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Apparent sound insulation in cold-formed steel-framed buildings
Hoeller, Christoph; Quirt, David; Zeitler, Berndt; Sabourin, Ivan

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Research Report (National Research Council of Canada. Construction), 2017-0407
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Construction

RR-337
Apparent Sound Insulationin Cold-Formed Steel-Framed
Buildings
Christoph Hoeller, David Quirt, Berndt Zeitler, Ivan Sabourin
07 April 2017

Apparent Sound Insulation in CFS-Framed Buildings
DRAFT 1st edition – October 2016

Page 1 of 108

ScopeThis Report presents the results from substantial experimental studies of sound transmission, together
with an explanation of calculation procedures to predict the sound transmission between adjacentspaces in a building whose walls and floors have cold-formed steel (CFS) framing.
This first edition contains mainly data for loadbearing steel framing formed from sheet steel withthickness from 1.37 mm (16 gauge) to 0.94 mm (20 gauge).
Non-loadbearing CFS studs formed from thinner steel (nominally 0.54 mm) are also commonly used but
these are not included in the data tables for sound transmission through wall assemblies in this Report.

Acknowledgments
The research studies on which this Report is based were supported by the Canadian Sheet Steel Building
Institute. The financial support and guidance on construction practices are gratefully acknowledged.

Disclaimer
Although it is not repeated at every step of this Report, it should be understood that some variation insound insulation is to be expected in practice due to changes in the specific design details, pooro k a ship, su stitutio of ge e i e ui ale ts , or simply rebuilding the construction. It would be
prudent to allow a margin of error of several ASTC points to ensure that a design will satisfy a specificrequirement.
Despite this caveat, the authors believe that methods and results shown here do provide a good
estimate of the apparent sound insulation for the types of constructions presented.

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Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Contents
1

Sound Transmission via Many Paths ............................................................................................. 1
1.1 Predicting Sound Transmission in a Building .................................................................................... 4
1.2 Standard Scenario for Examples in this Report ................................................................................ 5
1.3 Applying the Concepts of ISO Standards in an ASTM Environment ................................................. 7
1.4 Combining Sound Transmitted via Many Paths ................................................................................ 92

Sound Transmission through CFS-Framed Walls and Floors ........................................................ 13
2.1 Coding System for Specimen Descriptions ..................................................................................... 15
2.2 Wall Assemblies with CFS Framing ................................................................................................. 17
2.3 Floor/Ceiling Assemblies with CFS Framing .................................................................................... 23

3

Flanking Sound Transmission in CFS-Framed Constructions ........................................................ 29
3.1 Test Facility and Procedures for CFS-Framed Assemblies .............................................................. 29
3.2 Description of Flanking Specimen ................................................................................................... 32
3.3 Tested Junctions of CFS-Framed Floors with Walls ........................................................................ 40
3.4 Tested Junctions of CFS-Framed Walls with Walls ......................................................................... 55
3.5 Trends in Flanking Sound Transmission for CFS-Framed Constructions ......................................... 60

4

Predicting Sound Transmission in CFS-Framed Buildings ............................................................. 69
4.1 Calculation Procedure for CFS-Framed Walls and Floors ............................................................... 71
4.2 Calculation Examples for CFS-Framed Walls and Floors ................................................................. 74

5

Appendices of Sound Transmission Data .................................................................................... 91
5.1 Appendix A1: Transmission Loss Data for CFS-Framed Wall and Floor Assemblies ....................... 92

6

References and Explanatory Notes ............................................................................................. 98

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Chapter 1: Sound Transmission via Many Paths

1 Sound Transmission via Many Paths
The simplest approach to sound transmission between adjacent rooms in buildings considers only thesound transmission through the separating wall or floor. This perspective has been entrenched in North
American building codes, which for many decades have considered only the ratings for the separatingassembly: sound transmission class (STC) or field sound transmission class (FSTC) for airborne sources
and impact insulation class (IIC) for footstep noise.
Implicit in this approach (illustrated in Figure 1.1) is the simplistic assumption that sound is transmitted
only through the obvious separating assembly – the separating wall assembly when the rooms are sideby-side, or the floor/ceiling assembly when rooms are one-above-the-other. If the sound insulation isinadequate, this is attributed to errors in either the design of the separating assembly or theworkmanship of those who built it, and remediation focusses on that assembly. Unfortunately, thisparadigm is still common among designers and builders in North America.

Airborne
Sound
SourceTransmission
through wall

Airborne
Sound
SourceFlanking Transmission
via ceiling surfaces
Transmission
through wall
Flanking Transmission
via floor surfaces

Separating assembly

Figure 1.1: The drawings in Figure 1.1 and 1.2 show
a cross-section through a building with two adjacentrooms. Part of the sound from an airborne source in
one unit (represented by red loudspeaker in thedrawings, which could include anything from a hometheatre to people talking loudly) is transmitted tothe adjacent unit. The historic approach, illustrated
in Figure 1.1, considers only the direct soundtransmission through the separating assembly.

Figure 1.2: In reality, there are many paths forsound transmission between adjacent rooms,
including both direct transmission through theseparating assembly and indirect structure-borne
paths, a few of which are indicated here (seeSection 1.4 for more detail.) The structure-borne
paths usually significantly affect the overallsound transmission.

In reality, the technical issue is more complex, as illustrated in Figure 1.2. There is direct transmission ofsound through the separating assembly, but that is only part of the story of how sound is transmitted
between adjacent rooms. As shown in the figure, the airborne sound source excites all the surfaces inthe source space and all of these surfaces vibrate in response. Some of this vibrational energy istransmitted as structure-borne sound across the surfaces abutting the separating assembly, through thejunctions where these surfaces join the separating assembly, and into surfaces of the adjoining space.
These surfaces in the receiving room then radiate part of the vibrational energy as airborne sound. The
sound transmission by these paths is called flanking sound transmission.

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Chapter 1: Sound Transmission via Many Paths
It follows that the sound insulation between adjacent rooms is always worse than the sound insulation
provided by the obvious separating assembly. Occupants of the adjacent room actually hear the
combination of sound due to direct transmission through the separating assembly plus sound due tostructure-borne flanking transmission involving all the other elements coupled to the separatingassembly. Furthermore, there is also transmission of sound through leaks (openings) in the walls. The
importance of including all of the transmission paths has long been recognized in principle (and thefundamental science was largely explained decades ago, by Cremer et al [8]). The challenge has been to
reduce the complicated calculation process to manageable engineering that yields trustworthy
quantitative estimates, and to standardize that process to facilitate its inclusion in a regulatory
framework.
For design or regulation, there is well-established terminology to describe the overall soundtransmission including all paths between adjacent rooms. ISO ratings such as the weighted apparent
sound reduction i de R’w) have been used in many countries for decades, and ASTM E336 defines thecorresponding apparent sound transmission class (ASTC), which is used in the examples in this Report.
Although measuring the ASTC in a building (following ASTM Standard E336) is quite straightforward,
predicting the ASTC due to the set of transmission paths in a building is more complex. However,standardized frameworks for calculating the overall sound transmission have been developed. These
start from standardized measurements to characterize sub-assemblies, and have been used for morethan a decade to support performance-based European code systems.
In 2005, ISO published a calculation method, ISO 15712- , Buildi g a ousti s — Estimation of acoustic
performance of buildings from the performance of elements — Part 1: Airborne sound insulation
between rooms . This is o e pa t of a se ies of sta da ds: Pa t deals ith impact sound insulation
between rooms , Pa t deals ith ai o e sou d i sulatio agai st outdoo sou d , a d Pa t deals
ith transmission of indoor sound to the outside .
There are two significant impediments to applying the methods of ISO 15712-1 in a North American
context:
 ISO 15712-1 provides very reliable estimates for buildings constructed from heavy,homogeneous building elements, but not for buildings constructed from lightweight (steel- or
wood-) framed elements widely used in North America.
 ISO standards for building acoustics have many differences from the ASTM standards used by
the construction industry in North America – both in their terminology and in specific technicalrequirements for measurement procedures and ratings.
The following sections of this chapter outline a strategy for dealing with these limitations, both
explaining how to merge ASTM and ISO test data and procedures, and providing recommendations foradapting the calculation procedures for cold-formed steel-framed constructions.

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Chapter 1: Sound Transmission via Many Paths
This Report was developed in a project established by the National Research Council Canada and theCanadian Sheet Steel Building Institute to support the transition of construction industry practice tousing ASTC rather than STC for sound control objectives in the National Building Code of Canada (NBCC).
However, the potential range of application goes beyond the minimum requirements of the NBCC. The
Report also facilitates design to provide enhanced levels of sound insulation, and should be generally
applicable to construction with CFS-framed assemblies in both Canada and the USA.

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Chapter 1: Sound Transmission via Many Paths

1.1 Predicting Sound Transmission in a Building
As noted above, ISO 15712-1 provides reliable estimates for buildings constructed from heavy,homogeneous building elements, but it is less accurate for other common types of construction,
especially for constructions whose stiffness is directional such as lightweight wood-framed and steelframed constructions.
ISO 15712-1 has other limitations, too. For example, in several places (especially for lightweight framed
construction) the Standard identifies situations where the detailed calculation is not appropriate, butdoes not provide specific guidance on how to deal with such cases. Many of these limitations can beovercome by using data from laboratory testing following the procedures of the ISO 10848 series ofstandards; the four parts of ISO 10848 were developed by working groups of ISO TC43/2 to deal withmeasuring flanking transmission for various combinations of construction types and junctions. Because
the current (2005) edition of ISO 15712-1 replicates a European standard developed before 2000, it does
not reference more recent standards such as the ISO 10848 series, or the ISO 10140 series that are
replacing the ISO 140 series referenced in ISO 15712-1. The 2015 edition of the National Building Codeof Canada deals with these issues by specifying suitable procedures and test data to deal withcalculating ASTC for different types of construction. These procedures are also explained in the NRC
Research Report RR, Guide to Cal ulati g Ai o e “ou d T a s issio i Buildi gs.
For CFS-framed constructions1, the normal calculation procedure of ISO 15712-1 (both the Detailed
Method and the Simplified Method) must be modified to obtain accurate results. This Report outlines
the steps of the calculation process and the standard measurement data required for such calculations.
These modifications are consistent with the requirements in the 2015 edition of the National Building
Code of Canada.
This Report is restricted to consideration of buildings where all wall and floor assemblies are framedwith cold-formed steel (CFS) studs or joists. The scope could be expanded to include the combination of
CFS-framed assemblies with heavy concrete floor assemblies, by measuring the flanking soundtransmission for such combinations following the procedures of ISO 10848. However, at the time of
publication of this report, such data was not available.
In order to respect copyright, the Report does not reproduce the equations of ISO 15712-1, but it does
indicate which equations apply in each context and provides key adaptations of the ISO expressions
needed to apply the concepts in an ASTM context.

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1.2

Standard Scenario for Examples in this Report

The prediction of the sound transmitted in buildings depends not only on the construction details of thetransmission paths, but also on the size and shape of each of the room surfaces and on the soundabsorption in the receiving room. The ability to adjust the calculation to fit the dimensions in a specificbuilding or to normalize to different receiving room conditions enables a skilled designer to obtain moreaccurate predictions.
However, for purposes of this Report where results will be presented for a variety of constructions, easy
and meaningful comparison of results is facilitated by calculating all the examples for a common set ofroom geometry and dimensions. This is particularly useful where only small changes are made between
the construction details in the examples, since any change in the ASTC rating can then be attributed tothe changes which were made in the construction details.
Therefore, a Standard Scenario has been adopted for all the examples, with the following constraints:
 Sound is transmitted between adjacent rooms, either side-by-side or one-above-the-other.
 The adjacent rooms are mirror images of each other, (with one side of the separating assembly
facing each room, and constituting one complete face of each rectangular room).
The Standard Scenario is illustrated in Figures 1.3 and 1.4, for the cases where one room is beside theother, or one is above the other, respectively.
Figure 1.3:
Standard Scenario for theho izo tal room pai casewhere the pair of rooms
are side-by side with aseparating wall assembly
between the two rooms.

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Chapter 1: Sound Transmission via Many Paths
Figure 1.4:
Standard Scenario for thee ti al room pai casewhere one of the pair ofrooms is above the other,with the floor/ceilingassembly between thetwo rooms.

The pertinent dimensions and junction details are shown in Figures 1.3 and 1.4.
 Note the labelling of junctions at the four edges of the separating assembly (J1 to J4) in Figures 1.3
and 1.4. These junction designations are used in the design examples throughout this Report.
 For horizontal room pairs (i.e. rooms are side-by-side) the separating wall is 2.5 m high by 5 m wide,
flanking floor/ceilings are 4 m by 5 m and flanking walls are 2.5 m high by 4 m wide.
 For vertical room pairs (i.e. one room is above the other) the separating floor/ceiling is 4 m by 5 m
wide and flanking walls in both rooms are 2.5 m high.
 In general, it is assumed that junctions at one side of the room (at the separating wall if rooms are
side-by-side) are cross-junctions, while one or both of the other two junctions are T-junctions. This
enables the examples to illustrate typical differences between the two common junction cases.
 For a horizontal pair, the separating wall has T-junctions with the flanking walls at both the façadeand corridor sides, and cross-junctions at floor and ceiling.
 For a vertical pair, the façade wall has a T-junction with the separating floor, but the opposing
corridor wall has a cross-junction, as do the other two walls.
In practice, cases with cross-junctions at separating walls on either side and at the corridor side seem
quite common. Deviations from the Standard Scenario, such as room pairs where one room is an end
unit with T-junctions instead of cross-junctions, should tend to result in slightly higher ASTC ratings thanthe Standard Scenario.

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1.3

Applying the Concepts of ISO Standards in an ASTM Environment

Although the building acoustics standards developed by ASTM are very similar in concept to thecorresponding ISO standards, there are differences in the terminology and technical requirements
between the two which present numerous barriers to using a mix of standards from the two domains.
Although the ASTM standard E336 recognizes the contribution of flanking to apparent soundtransmission, there is neither an ASTM standard for measuring the structure-borne flanking
transmission that often dominates sound transmission between rooms, nor an ASTM counterpart ofISO 15712-1 for predicting the combination of direct and flanking transmission. In the absence ofsuitable ASTM standards, this Report uses the procedures of ISO 15712-1 and data from thecomplementary ISO 10848 series, but connects this ISO calculation framework to the ASTM terms andtest data widely used by the North American construction industry. This methodology combines
identifying where data from ASTM laboratory tests can reasonably be used in place of their ISO
counterparts, and presenting the results using ASTM terminology (or new terminology for flanking
transmission that is consistent with existing ASTM terms) to facilitate their use and understanding by a
North American audience. Some obvious counterparts in the terminology are presented in Table 1.1.
ISO Designation

Description

ASTM Counterpart

ISO 10140 Parts 1 and 2(formerly ISO 140-3)

Laboratory measurement of airborne
sound transmission through a wall or floor

ASTM E90

sound reduction index, R(from ISO 10140-2)

Fraction of sound power transmitted (indB) at each frequency, in laboratory test

sound transmission loss
TL (ASTM E90)

weighted sound reduction
index, Rw (ISO 717-1)

Single-number rating determined from R
or TL values in standard frequency bands

sound transmission class
STC (ASTM E413)

apparent sound reduction
index, R’ (ISO 140-4)

Fraction of sound power transmitted(expressed in dB) at each frequency,
including all paths in a building

weighted apparent soundreduction index, R’w(ISO 717-1)

Single-number rating determined from R’
or ATL values in standard frequency bands

apparent soundtransmission loss
ATL (ASTM E336)
apparent soundtransmission class, ASTC
(ASTM E413)

Table 1.1: Standards and terms used in ISO 15712-1 for which ASTM has close counterparts
Note that the des iptio
ou te pa t does ot i ply that the ASTM and ISO standards or terms areexactly equivalent. RW a d “TC a e ot i te ha gea le. Neithe a e R’W and ASTC because of systematicdifferences in the calculation procedures. However, the laboratory test used to measure airborne soundtransmission through wall or floor assemblies – ASTM E90 and its counterpart ISO 10140-2 – are basedon essentially the same procedure, with minor variants in facility requirements. Therefore, theeasu ed ua tities sou d t a s issio loss f o the A“TM E test a d sou d edu tio i defrom the ISO standard are sufficiently similar so that data from ASTM E90 tests can be used in place ofApparent Sound Insulation in CFS-Framed Buildings
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Chapter 1: Sound Transmission via Many Paths
data from ISO 10140-2 tests in the calculations of ISO 15712-1 to obtain a sensible answer. Similarly, thesimplified calculation of ISO 15712-1 may be performed using STC ratings to predict the ASTC rating. The
lose pa allel et ee sou d edu tio i de a d sou d t a s issio loss also ea s that esultsfrom ISO 15712-1 calculations o all e p essed as R’ alues) can confidently be treated as calculated
apparent sound transmission loss (ATL) values and then used in the procedure of ASTM E413 to
calculate the ASTC rating which is the objective for designers or regulators in the North American
context.
For purposes of this Report, a glossary of new terms with counterparts in ISO 15712-1 (using
terminology consistent with measures used in ASTM standards) and of other key terms from pertinent
ISO standards such as ISO 15712 and ISO 10848 is presented in Table 1.2.
Terms used in this Report

Description

Structural reverberation
time (TS)

Structural reverberation time is a measure indicating the rate of decay ofvibration energy in an element and can apply either to a laboratory wallor floor specimen, or to a wall or floor assembly in-situ in a building.

Transmission loss in-situ(TLsitu)Transmission loss in-situ is the counterpart of sound reduction index insitu (Rsitu) described in ISO 15712 as "the sound reduction index of anelement in the actual field situation".

Flanking soundtransmission loss
(Flanking TLij)

Flanking transmission loss is the counterpart of flanking sound reduction
index (Rij) in ISO 15712. It is a measure of sound transmission via theflanking path from element i in the source room to element j in thereceiving room, normalised like apparent sound transmission loss, as
described in Section 1.4.

Flanking soundtransmission class(Flanking STCij)

Flanking STC is the single-number rating calculated from the flanking
transmission loss following the STC calculation procedure of ASTM E413.

Table 1.2: Key terms used in this Report to deal with concepts from ISO 15712-1 and ISO 10848 forwhich ASTM acoustics standards have no counterparts.
In addition, several scientific terms used in ISO-15712 at various stages of the calculation have beenused without change. These include: radiation efficiency, internal loss factor, total loss factor,
equivalent absorption length, and transmission factor. They are described in the glossary in Annex A of
ISO 15712-1.

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1.4 Combining Sound Transmitted via Many Paths
The calculations of ISO 15712-1 must deal with combining the sound power transmitted via the direct
path and via a set of flanking paths. To discuss this, it is useful to introduce the convention for labelling
the transmission paths that is used in ISO 15712-1, as explained in Figure 1.5.
Figure 1.5: This figure shows the labelling
convention for transmission paths used in
ISO 15712-1. Consider transmission from asource room at the left to the receivingroom beside it. Each transmission pathinvolves one surface in the source room(denoted by a capital letter) and one in thereceive room (lower case). Directtransmission through the separating wall ispath Dd. For each edge of the separatingassembly there are three flanking paths,
each involving a surface in the source roomand one in the receiving room, that connect
at this edge: Ff from flanking surface F toflanking surface f, Df from direct surface D
to flanking surface f, and Fd from flanking
surface F to direct surface d in the receiving
room.
Note that the letter F or f denotes flanking surface, and D or d denotes the surface for directtransmission, i.e. the surface of the separating assembly. These surfaces may be either wall or
floor/ceiling assemblies, as detailed in the following Table 1.3.

Room Pair

Surfaces D and d

Horizontal(Fig. 1.3)

Separating wall

Vertical(Fig. 1.4)

Separating floor/ceiling

Flanking Surfaces F and f
Junction 1: floor F and f
Junction 2: façade wall F and f
Junction 3: ceiling F and f
Junction 4: corridor wall F and f
Junction 1: wall F and f
Junction 2: façade wall F and f
Junction 3: wall F and f
Junction 4: corridor wall F and f

Junction(Standard Scenario)
Cross junction
T-junction
Cross junction
T-junction
Cross junction
T-junction
Cross junction
Cross junction

Table 1.3: Surfaces (D, d, F and f) for flanking paths at each junction, as in the Standard Scenario

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Chapter 1: Sound Transmission via Many Paths
In Canada, building elements are normally tested according to the ASTM E90 [1] standard and buildingcode requirements are given in terms of apparent sound transmission class (ASTC) determined from theapparent sound transmission loss (ATL) for the set of frequency bands from 125 Hz to 4000 Hz, following
the procedure in ASTM E413. Merging this context with using the ISO 15712-1 procedures in thisReport, the te s di e t sound t a s issio loss a d fla ki g sound t a s issio loss ha e ee
introduced to provide consistency with ASTM terminology while matching the function of the direct andflanking sound reduction indices defined in ISO 15712-1.
Section 4.1 of ISO 15712-1 defines a process to calculate apparent sound transmission by combining thesound power transmitted via the direct path and the twelve first-order flanking paths (3 at each edge ofthe separating assembly, as illustrated in Figure 1.5). Equation 14 in ISO 15712-1 is recast here withslightly different grouping of the paths (treating the set of paths at each edge of the separating assemblyin turn) to match the presentation approach chosen for the examples in this Report.
The apparent sound transmission loss (ATL) between two rooms (assuming the room geometry ofSection 1.2 and neglecting sound that is by-passing the building structure, for example soundtransmitted through leaks and ducts) is the resultant of the direct sound transmission loss (TL )through the separating wall or floor element and the set of flanking sound transmission loss
contributions of the three flanking paths (TL� , TL� , and TL ) for each junction at the four edges ofthe separating element as shown in Fig. 1.5.
� �= −∙ log− . ∙ ���

4

+ ∑ (
=

− . ∙ ���+− . ∙ ���+− . ∙ ���)Eq. 1.1

Note that this equation differs slightly from the calculation of the apparent sound transmission definedin Equation 14 of ISO 15712-1. Eq. 1.1 of this Report treats the set of paths at each edge of theseparating assembly in turn to match the presentation for the examples in this Report. Eq. 1.1 isuniversally valid for all building systems, and the remaining challenge is to find the right expressions to
calculate the path transmission for the chosen building system and situation.
Each of the flanking sound transmission loss values for a specific path is normalized like the apparent
sound transmission loss, and can be considered as the ATL that would be observed if only this single
path were contributing to the sound transmitted into the receiving room. Normalization of direct andflanking transmission input data so that the receiving room absorption is numerically equal to the areaof the separating assembly (i.e. using apparent sound transmission loss and ASTC as the measure ofsystem performance) requires suitable corrections to data calculated according to ISO 15712-1, orvalues of flanking transmission loss from laboratory testing according to ISO 10848, so that the set ofpath transmission loss values can be properly combined or compared. This normalization process is fully
described in the calculation procedures in Chapter 4.

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Chapter 1: Sound Transmission via Many Paths
The standard ISO 15712-1 describes two methods of calculating the apparent sound insulation in abuilding: the Detailed Method and the Simplified Method. This Report describes the Simplified Method
to calculate the apparent sound insulation in a building consisting of CFS-framed elements. The
Simplified Method uses the single-number ratings (STC or Flanking STC for each transmission path)instead of the frequency-dependent transmission loss values and yields the ASTC directly:
�

�=−

∙ log

[

− . ⋅

��

+∑

4

=

(

− . ⋅

��

+

− . ⋅

��

+

− . ⋅

��

)]

Eq. 1.2

The Simplified Method has been widely used by designers in Europe for many years for calculations
based on RW data. Its primary advantage is the simplicity of the procedure, which makes it usable bynon-specialists, as illustrated by the worked examples in Section 4.2. Although it is less rigorous thanthe Detailed Method, the differences between the results using the two methods are small, and thecalculations for the Simplified Method use approximations that should ensure the results are slightly
conservative.
Cautions and limitations to examples presented in this Report:
This Report was developed to support the transition to ASTC ratings for sound control objectives in the
National Building Code of Canada. Simplifications were made to meet the specific needs of thatapplication, where sound insulation is addressed only in the context of multi-unit residential buildings.
The simplifications include that:

Transmission around or through the separating assembly due to leaks at its perimeter or
penetrations such as ventilation systems are assumed negligible.

Indirect airborne transmission (for example airborne flanking via an unblocked attic or crawl
space) is assumed to be suppressed by normal fire blocking requirements.

For adjacent occupancies in a multi-family residential building, these two issues should be dealt with bynormal good practice for fire and sound control between adjoining dwellings.
If this Report is applied to situations other than separation between adjacent units in multi-family
residential buildings, some of these issues may have to be explicitly addressed in the calculation process.
For example, for adjoining rooms within a single office or home, flanking paths such as ventilation ducts
or open shared plenum spaces may be an issue. The flanking transmission associated with these
additional paths should be determined and included in the calculated ASTC. ISO 15712-1 includes
specific guidance for such issues, and the examples in this Report allow for such a correction.

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Chapter 2: Sound Transmission through CFS-Framed Walls and Floors

2 Sound Transmission through CFS-Framed Walls and Floors
This chapter presents the results of experimental sound transmission loss tests of wall and floor
assemblies with several variants of CFS framing. The tested assemblies include assemblies with a varietyof framing details and linings covering the surfaces of the CFS framing.

ASTM E90 Test Method
Transmission loss tests of wall and floor specimens were conducted i NRC’s Wall a d Floo “ou dTransmission Facilities according to the ASTM E90 test protocol [1]. Concept drawings of the soundtransmission facilities are presented in Figure 2.1.
Figure 2.1: A concept drawing of the Wall
Sound Transmission Facility at the NRC ispresented in the upper drawing. The NRC
Floor Sound Transmission Facility, shown in
the lower drawing, is similar except that one
room is above the other.
In both cases, full scale test assemblies aremounted in the massive concrete movable
test frames between the two reverberant
rooms. The test openings are 3.66 m wideand 2.44 m high for walls and 4.70 m by
3.78 m for floors.
In the wall facility, the rooms (designatedla ge ha e and s all ha e haveapproximate volumes of 250 m3 and 140 m3
respectively. In the floor facility, bothchambers have volumes of approximately
175 m3. All the facility rooms are hardwalled reverberation chambers that are
vibration-isolated from each other and fromthe specimen frame. The rooms have fixed
and/or moving diffusor panels to enhance
diffusivity of the sound fields.
The facilities (including instrumentation)and the test procedures satisfy or exceed all
requirements of ASTM E90.

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Each facility is equipped with an automated measurement system for data acquisition and postprocessing. In each room, a calibrated Brüel & Kjær condenser microphone (type 4166 or 4165) withpreamp is moved under computer control to nine positions, and measurements are made in both rooms
using a National Instruments NI-4472 data acquisition system installed in a computer. Each room hasfour bi-amped loudspeakers driven by separate amplifiers and noise sources. To increase randomness ofthe sound field, there are fixed diffusing panels in each room.
Measurements of the airborne sound transmission loss (TL) were conducted in accordance with therequirements of ASTM E90-09, “ta da d Method for Laboratory Measurement of Airborne Sound
Transmission Loss of Building Pa titio s . Airborne sound transmission loss tests were performed inboth directions – from the large chamber to the small chamber and vice-versa for walls, and from theupper chamber to the lower chamber and vice-versa for floors. The results presented in this Report are
given as the average of the two transmission directions to reduce measurement uncertainty due tofactors such as calibration errors and local variations in the sound fields.
For every measurement, sound transmission loss values were calculated from the average soundpressure levels in the source room and the receiving room and the average reverberation times of thereceiving room. One-third octave band sound pressure levels were measured for 32 seconds at nine
microphone positions in each room and then averaged to get the average sound pressure level in eachroom. Five sound decays were averaged to get the reverberation time at each microphone position in
the receiving room; these times were averaged to get the average reverberation times for each room.
The frequency-dependent sound transmission loss was measured in one-third octave bands in thefrequency range from 50 Hz to 5000 Hz. However, only the frequency range between 125 Hz and4000 Hz is considered in the calculation of the sound transmission class (STC) single-number rating
according to ASTM E413 [3].
The impact sound transmission was also measured with both the standardized tapping machine(according to ASTM E492) and the heavy soft rubber ball (according to ISO 10140), but those results are
not within the scope of this edition of this Report.
The sound transmission loss data are presented as follows in this Report: The sets of one-third octave band sound transmission loss results from 50 Hz to 5000 Hz arepresented in the Appendix A1.
 Graphs of the transmission loss data for some wall and floor assemblies are presented in thediscussion of trends in Sections 2.2.1 and 2.3.1.
 This chapter presents a more compact summary of results in terms of the single-number STC
ratings that are required for the calculations in Chapter 4 to determine the ASTC rating.

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Chapter 2: Sound Transmission through CFS-Framed Walls and Floors

2.1 Coding System for Specimen Descriptions
A coding system is used throughout this Report to avoid long descriptions of floor or wall constructions.
Each surface layer in a floor or wall is coded as follows:

An integer representing the number of layers of material; if the number of layers is one, theleading 1 is omitted;
A sequence of letters to indicate the material in the layer (see Table 2.1 below);
A number representing the thickness in mm of each sheet or element in the layer;
Underscores separating the codes for each layer.

The coding system is also applied to elements that do not constitute surface layers such as joists, studs,
and resilient metal channels. For such elements, the number following the letters is the depth of eachelement (the dimension along the axis perpendicular to the surface of the assembly) and the number inparentheses following the depth code is the separation between adjacent elements.
Table 2.1: Examples of the codes used to identify materials and to describe constructions.
CodeMaterial

CARxx

CarpetVINxx

Vinyl sheet flooring

LAMxx

Laminate flooring planks

CONxx

Concrete

Gxx

Gypsum board

GCONxxGypsum concrete

mm thick

GFBxx

Glass fibre batts

mm thick

MFBxx

Mineral fibre batts

CFLxx

Blown-in cellulose fibremm thick

OSBxx

Oriented strand board

mm thick

SJxx(ss)

Cold-formed steel (CFS) C-joists with nominal depth ofmm, spaced ss mm on centers

SSxx(ss)

Cold-formed steel (CFS) studs with nominal depth ofmm, spaced ss mm on centers

RCxx(ss)

Resilient metal channels with nominal depth ofspaced ss mm on centers

CORSTExx

Corrugated steel deck formed with profilethi kmm thickmm thickmm thick

Apparent Sound Insulation in CFS-Framed Buildings
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mm deep

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Note that the coding system is a convenience and actual dimensions may not be exactly as coded. For
example, the nominal 16 mm thick gypsum board would be labelled by the manufacturer as 5/8 in or
15.9 mm thick. Other details are given for each specimen in Sections 2.2 and 2.3 and in the appendices.
For brevity, not all pertinent parameters are included in the short codes. For example, the thickness ofthe steel in CFS joists or studs is not indicated. This information is given separately in specimen
descriptions in the tables of measurement results and the calculation examples.
Thus the code OSB15_SJ203(406)_GFB150_RC13(610)_2G16 describes a floor with the following
construction details:






A 15 mm thick oriented strand board subfloor;
38 x 203 mm cold-formed steel joists, spaced 406 mm on centers;
150 mm thick glass fibre batts in the joist cavities;
12.7 mm deep resilient metal channels screwed to the joists and oriented perpendicular to
the joists, spaced 610 mm on centers;
Two layers of gypsum board, each 15.9 mm thick, attached to the resilient metal channels.

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2.2 Wall Assemblies with CFS Framing
The focus of this section is the measured sound transmission loss of wall assemblies comprised of aframe of cold-formed steel (CFS) studs with gypsum board attached on both sides of the studs. The
gypsum board was either fastened directly to the studs or supported on resilient metal channels. Mostof the tested assemblies had sound absorbing material in the cavities between the studs.
The typical construction of the wall specimens tested as part of this study had a single row ofloadbearing CFS studs as shown in Figure 2.2.1.
Figure 2.2.1:
Horizontal cross-section of a wall
assembly with a single row ofloadbearing CFS studs showing
typical components. Variations andelement properties are listed in
more detail on the right.

1. Single row of cold-formed steel (CFS) loadbearing studs 1(either 38 x 92 mm or 38 x 152 mm cross section) spaced
either 406 mm or 610 mm on center.
2. Surface of 1 or 2 layers of fire-rated gypsum board2
screwed directly to one face of the CFS studs. Gypsum
board may be designated either as G13 (nominal
thickness of 1/2 inch, 12.7 mm) or as G16 (nominal
thickness of 5/8 inch, 15.9 mm).
3. Sound absorbing material3 in the cavities between studs
may be glass fiber batts (GFB) or mineral fiber batts (MFB)or blown-in cellulose fiber (CFL) of various thicknesses.
4. Resilient metal channels designated RC13 in the coding,formed from light sheet steel with suitable profile4 andscrewed to the faces of the CFS studs. Resilient channels
spaced either 406 mm or 610 mm on center.

Drawings are not to scale; see
Figure 3.2.2 for a scale drawing of
one variant.

5. Surface of 1 or 2 layers of fire-rated gypsum board2
screwed to resilient metal channels whose other flange is
supported from the CFS studs. Gypsum board may bedesignated either as G13 (nominal thickness of 1/2 inch,
12.7 mm) or as G16 (nominal thickness of 5/8 inch,
15.9 mm).

NOTE: The wall tests reported here include a series of specimens tested in 2014, plus some specimens
tested in 1999-2000. All aspects of the facility and measurement procedure were identical for the twodatasets. For comparable cases, the STC rating differed by 0 or 1.

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Chapter 2: Sound Transmission through CFS-Framed Walls and Floors
Table 2.2.1(a): Measured STC values for wall assemblies with a single row of loadbearing CFS studs1 witha cross section of 38 x 152 mm. The results are numbered and organized in groups by common features
within each group. Specimens 01-09 have no resilient metal channels. Specimens 11-19 have resilient
metal channels but no sound absorbing material. Specimens numbered 21 or higher have both resilient
metal channels and sound absorbing material. These are grouped by thickness of sound absorbing batts,
spacing between studs, or thickness of the studs’ steel.

Specimen ID

SteelThickness

Descriptive Short Code

Test Reference

STC

CFS-S152-W01

G16_SS152(406)_GFB152_G16

1.37 mm

TLA-14-051

42

CFS-S152-W02

G16_SS152(406)_GFB152_2G16

1.37 mm

TLA-14-052

45

CFS-S152-W03

2G16_SS152(406)_GFB152_2G16

1.37 mm

TLA-14-053

48

CFS-S152-W11

G16_SS152(406)_RC13(406)_G16

1.37 mm

TLA-14-047

42

CFS-S152-W12

2G16_SS152(406)_RC13(406)_G16

1.37 mm

TLA-14-048

47

CFS-S152-W13

G16_SS152(406)_RC13(406)_2G16

1.37 mm

TLA-14-050

48

CFS-S152-W14

2G16_SS152(406)_RC13(406)_2G16

1.37 mm

TLA-14-049

53

CFS-S152-W21

G16_SS152(406)_GFB92_RC13(406)_G16

1.37 mm

TLA-14-044

49

CFS-S152-W22

2G16_SS152(406)_GFB92_RC13(406)_G16

1.37 mm

TLA-14-045

53

CFS-S152-W23

2G16_SS152(406)_GFB92_RC13(406)_2G16

1.37 mm

TLA-14-046

57

CFS-S152-W31

G16_SS152(406)_GFB152_RC13(406)_G16

1.37 mm

TLA-14-041,054,055

49

CFS-S152-W32

2G16_SS152(406)_GFB152_RC13(406)_G16

1.37 mm

TLA-14-056

54

CFS-S152-W33

2G16_SS152(406)_GFB152_RC13(406)_2G16

1.37 mm

TLA-14-042,057,059

58

CFS-S152-W34

2G13_SS152(406)_GFB152_RC13(406)_2G13

1.37 mm

TLA-14-043

57

CFS-S152-W41

G16_SS152(610)_GFB92_RC13(406)_G16

1.37 mm

TLA-14-063

50

CFS-S152-W42

2G16_SS152(610)_GFB92_RC13(406)_G16

1.37 mm

TLA-14-064

55

CFS-S152-W43

2G16_SS152(610)_GFB92_RC13(406)_2G16

1.37 mm

TLA-14-065

59

CFS-S152-W44

2G16_SS152(610)_GFB152_RC13(406)_2G16

1.37 mm

TLA-14-066

60

CFS-S152-W51

G16_SS152(406)_GFB152_RC13(406)_G16

1.09 mm

TLA-14-074

50

CFS-S152-W52

2G16_SS152(406)_GFB152_RC13(406)_G16

1.09 mm

TLA-14-075

54

CFS-S152-W53

2G16_SS152(406)_GFB152_RC13(406)_2G16

1.09 mm

TLA-14-076

58

NOTE: In some cases, tests were repeated on nominally identical specimens. In such cases, the STC
values differed by 0 or 1, and the results were averaged; these cases can be identified in the table bytheir multiple test references.

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Chapter 2: Sound Transmission through CFS-Framed Walls and Floors
Table 2.2.1(b): Measured STC values for wall assemblies with a single row of loadbearing CFS studs1 witha cross section of 38 x 92 mm. The results are numbered and organized in groups by common features
within each group. Specimens 01-02 have no resilient metal channels. Specimens 11-12 have resilient
metal channels but no sound absorbing material. Specimens numbered 21 or higher have both resilient
metal channels and sound absorbing material. These are grouped by thickness of the studs’ steel (21-27
were designated as 16 gauge) or by spacing between the framing elements (studs or resilient channels).
Specimen ID

Descriptive Short Code

Steel
Thickness

Test Reference

STC

CFS-S92-W01

G16_SS92(406)_GFB92_G16

1.37 mm

TLA-14-073

38

CFS-S92-W02

G13_SS92(406)_MFB89_2G13

0.94 mm

TLA-99-133a

40

CFS-S92-W11

2G13_SS92(406)_RC13(610)_2G13

0.94 mm

TLA-00-063a

50

CFS-S92-W12

2G16_SS92(406)_RC13(610)_2G16

0.94 mm

TLA-00-075a

51

CFS-S92-W21

G16_SS92(406)_GFB92_RC13(406)_G16

1.37 mm

TLA-14-067

45

CFS-S92-W22

G16_SS92(406)_GFB92_RC13(406)_2G16

1.50 mm

TLA-00-083a

50

CFS-S92-W23

2G16_SS92(406)_GFB92_RC13(406)_G16

1.37 mm

TLA-14-068

52

CFS-S92-W24

2G16_SS92(406)_GFB92_RC13(406)_2G16

1.37 mm

TLA-14-069

57

CFS-S92-W25

2G16_SS92(406)_GFB92_RC13(406)_2G16

1.50 mm

TLA-00-085a

57

CFS-S92-W26

2G13_SS92(406)_GFB92_RC13(406)_2G13

1.50 mm

TLA-00-079a

57

CFS-S92-W27

2G13_SS92(406)_MFB89_RC13(406)_2G13

1.50 mm

TLA-00-081a

56

CFS-S92-W31

G13_SS92(406)_GFB92_RC13(406)_G13

0.94 mm

TLA-00-105a

45

CFS-S92-W32

G13_SS92(406)_GFB92_RC13(406)_2G13

0.94 mm

TLA-00-103a

51

CFS-S92-W33

G13_SS92(406)_MFB89_RC13(406)_2G13

0.94 mm

TLA-99-127a,129a

51

CFS-S92-W34

G13_SS92(406)_CFL92_RC13(406)_2G13

0.94 mm

TLA-00-067a

51

CFS-S92-W35

G13_OSB12_SS92(406)_MFB89_RC13(406)_2G13

0.94 mm

TLA-99-135a

57

CFS-S92-W36

2G13_SS92(406)_GFB92_RC13(406)_2G13

0.94 mm

TLA-00-065a,101a

57

CFS-S92-W37

G16_SS92(406)_GFB92_RC13(406)_2G16

0.94 mm

TLA-00-069a

51

CFS-S92-W38

2G16_SS92(406)_GFB92_RC13(406)_2G16

0.94 mm

TLA-00-071a

58

CFS-S92-W41

G13_SS92(610)_MFB89_RC13(406)_2G13

0.94 mm

TLA-99-137a

55

CFS-S92-W51

G13_SS92(406)_GFB92_RC13(610)_G13

0.94 mm

TLA-00-095a

47

CFS-S92-W52

G13_SS92(406)_GFB92_RC13(610)_2G13

0.94 mm

TLA-00-097a

54

CFS-S92-W53

G13_SS92(406)_MFB89_RC13(610)_2G13

0.94 mm

TLA-99-123a

52

CFS-S92-W54

2G13_SS92(406)_GFB92_RC13(610)_2G13

0.94 mm

TLA-00-099a

59

CFS-S92-W55

G16_SS92(406)_GFB92_RC13(610)_G16

0.94 mm

TLA-00-089a

49

CFS-S92-W56

G16_SS92(406)_GFB92_RC13(610)_2G16

0.94 mm

TLA-00-091a

54

CFS-S92-W57

2G16_SS92(406)_GFB92_RC13(610)_2G16

0.94 mm

TLA-00-073a,093a

59

NOTE: In some cases, tests were repeated on nominally identical specimens. In such cases, the STC
values differed by 0 or 1, and the results were averaged; these cases can be identified in the table bytheir multiple test references.

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Chapter 2: Sound Transmission through CFS-Framed Walls and Floors

2.2.1 Trends in the Sound Transmission for CFS-Framed Walls
The effects of key parameters on the sound transmission loss of CFS-framed walls are described briefly
in this section. A more thorough parametric study was presented in previous publications [16].

Effect of Gypsum Board Layers:
The change in the construction detail of the CFS-framed walls with the most obvious effect on the soundtransmission loss values was the addition of extra layers of gypsum board. Figure 2.2.2 presents thesound transmission loss observed when an additional layer of gypsum board is added on each side ofwall CFS-S152-W21 (which has resilient channels on one side).

Figure 2.2.2:
Sound transmission loss for a set of
CFS-framed wall assemblies withidentical framing and soundinsulating batts, but different layersof gypsum board. Each of the threewall assemblies had resilient
channels on one side.

Changes very similar to those evident in Figure 2.2.2 were observed for other cases (different framing
details, different insulation, different type of gypsum board, etc.) when a second layer of gypsum board
was added on either side of the wall.
The individual changes and the mean change due to adding a second layer on either side are shown in
Figure 2.2.3 for all the specimens with 152 mm CFS studs.
The individual changes due to adding a second layer of gypsum board were scattered around the mean,
with a standard deviation of about 1 dB. There was a clear overall trend, with an increase in the soundtransmission loss of 5 to 6 dB at the lower and higher frequencies and a broad dip in the mid
frequencies. The trend is consistent between samples and the same trend was observed for the
specimens with 92 mm CFS studs in this study, and in previous studies [13.6] including other types offraming.

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Chapter 2: Sound Transmission through CFS-Framed Walls and Floors

Figure 2.2.3:
Change in sound transmission loss
for pairs of CFS-framed wall
assemblies with identical framing
and sound insulating batts, when asecond layer of gypsum board isadded on either side.
The mean change is shown by thesolid line. Individual cases scatteraround the mean with a standard
deviation of about 1 dB for eachthird-octave band.

Effect of Cavity Absorption
Adding sound absorbing material to the wall cavity has a significant effect if the gypsum board on atleast one side is mounted on resilient metal channels as shown in Figure 2.2.4.

Figure 2.2.4:
Sound transmission loss for a set of
CFS-framed wall assemblies withidentical framing and layers ofgypsum board, but different
amounts of sound absorbing
material in the inter-stud cavities.

The change in STC rating due to filling the inter-stud cavities with sound absorbing material is similar to
the improvement observed when the layers of gypsum board are doubled on both sides. Partially fillingthe cavity (the case with 92 mm absorbing batts) provides most of the effect.

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Chapter 2: Sound Transmission through CFS-Framed Walls and Floors
The effect of changing the type of sound absorbing material filling the cavities is shown in Figure 2.2.5.

Figure 2.2.5:
Sound transmission loss for a set of
CFS-framed wall assemblies withidentical framing and layers ofgypsum board, but different typesof sound absorbing material in theinter-stud cavities.

Although differences are evident among the sound transmission loss data with the 3 types of soundabsorbing materials, the differences are insignificant between 100 Hz and 300 Hz (which are dominant indetermining the STC rating for these specimens). All three specimens have an STC rating of 51, despite
the change from glass fiber to mineral fiber to cellulose fiber. This minimal effect on the STC rating is
consistent with the finding in previous NRC studies [13.7 and 13.8.] with other types of framing.

Effect of Other Parameters
The effect of other specimen parameters on the sound transmission loss can be summarized as follows:






The thickness of the material used to fabricate the CFS studs has only a small effect. The STC
rating increases by 1-2 points if studs with thinner steel are used.
Increasing the spacing between the CFS studs from 406 mm on centers to 610 mm on centerstypically increases the STC rating by 1-2 points for the walls used in this study; increasing the
spacing between resilient metal channels has a similar effect.
Changing the depth of the steel studs from 92 mm to 152 mm studs can increase the STC rating
by up to 4 points on walls with resilient channels.
The use of flat straps and bridging channels in loadbearing CFS-framed walls was found to havea negligible effect on the STC rating.

A more detailed analysis of these parameters is presented in a previous publication [16].

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Chapter 2: Sound Transmission through CFS-Framed Walls and Floors

2.3

Floor/Ceiling Assemblies with CFS Framing

The focus of this section is on sound transmission through floor/ceiling assemblies comprised of a coldformed steel (CFS) frame with a floor deck fastened directly to the top of the joists and a gypsum board
ceiling supported below the joists on resilient metal channels.
The typical construction of the floor specimens framed with CFS C-joists is shown in Figure 2.3.1. Thechanges for adding typical flooring are given in Table 2.3.2
Figure 2.3.1:
Vertical cross-section through a floor assemblywith loadbearing CFS joists showing typicalcomponents. The upper drawing shows a crosssection perpendicular to the long axis of the joists.
The drawing below shows a cross-section parallelto the joists. Variations and element properties arelisted in more detail on the right.

1. Subfloor comprised of a corrugated steel panscrewed to the top of the joists, with concreteor gypsum concrete installed on top of thepan. The thicknesses tested include concretewith average thickness of 40 mm (CON40) andgypsum concrete with average thickness of 32
mm (GCON32). The total thickness of the
subfloor was about 7 mm greater than the
average concrete thickness.
2. Cold-formed steel (CFS) loadbearing joists 1(sizes tested include cross sections of
38 x 317 mm, 38 x 254 mm, or 38 x 203 mm).
The joists were spaced 406 mm on center andwere fastened to framing headers of matching
depth. The thickness of the steel from which
the joists were formed is listed in Table 2.3.1.
3. Sound absorbing material3 in the joist cavities
may be glass fiber batts (GFB) or mineral fiber
batts (MFB) or blown-in cellulose fiber (CFL).
4. Resilient metal channels4 designated RC13 in
the coding were formed from light sheet steel
with a suitable profile, and were screwed to
the faces of the CFS joists. They may be spaced
either 406 mm or 610 mm on centers.

5. Fire-rated gypsum board2 screwed to resilient
metal channels whose other flange was
supported from the CFS joists. Gypsum board
may be designated either as G13 (nominal
thickness of 1/2 inch, 12.7 mm) or as G16
Drawings are not exactly to scale; see Figure 3.2.3(nominal thickness of 5/8 inch, 15.9 mm).
for a scale drawing of one variant.
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Chapter 2: Sound Transmission through CFS-Framed Walls and Floors
Table 2.3.1: Measured STC values for floor assemblies with cold-formed steel (CFS) C-joists with a crosssection of 38 x 203 mm, 38 x 254 mm, or 38 x 317 mm. The results are organized in groups by common
subfloor and steel framing within each group, and the specimen numbers reflect differences in the
gypsum board ceilings or differences in the sound absorbing material installed between the joists.
Specimen

Descriptive Short Code

Steel
Thickness

Test
Reference

STC

CFS-J317-F01

GCON32_CORSTE14_SJ317(406)_GFB92_RC13(305)_G16

1.37 mm

TLF-14-063,067

56

CFS-J317-F02

GCON32_CORSTE14_SJ317(406)_GFB92_RC13(305)_2G16

1.37 mm

TLF-14-066

60

CFS-J254-F01

GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16

1.37 mm

TLF-14-050,059

57

CFS-J254-F02

GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_2G16

1.37 mm

TLF-14046,048,049

60

CFS-J254-F03

GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G13

1.37 mm

TLF-14-061

56

CFS-J254-F04

GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_2G13

1.37 mm

TLF-14-062

60

CFS-J203-F01

CON40_CORSTE15_SJ203(406)_RC13(406)_2G13

1.22 mm

TLF-03009a,011a

62

CFS-J203-F02

CON40_CORSTE15_SJ203(406)_GFB90_RC13(406)_2G13

1.22 mm

TLF-03-005a

68

CFS-J203-F03

CON40_CORSTE15_SJ203(406)_MFB90_RC13(406)_2G13

1.22 mm

TLF-03-007a

68

CFS-J203-F04

CON40_CORSTE15_SJ203(406)_CFL200_RC13(406)_2G13

1.22 mm

TLF-03-031a

70

CFS-J203-F05

CON40_CORSTE15_SJ203(406)_CFS130_RC13(406)_2G13

1.22 mm

TLF-03-039a

68

Table 2.3.2: The measured ΔSTC values for floor finishes installed on top of the floor assemblies with agypsum concrete topping. The results for laminated flooring (LAM10_FOAM3) and for carpet(CAR11_UDLY9) are average values with the same finish floor installed on multiple floor assemblies. Allof these ΔSTC values are suitable for flooring installed over gypsum concrete subfloor of similar
thickness to the tested case. (GCON32 has an average thickness of 32 mm).
Flooring ID

Descriptive Short Code

Test Reference

ΔSTC

ΔTL-CFS-F01

VIN2 on GCON32

TLF-14-070,063

0

ΔTL-CFS-F02

LAM10_FOAM3 on GCON32

TLF-14-047,052,064,065

2

ΔTL-CFS-F03

CAR11_UDLY9 on GCON32

TLF-14-053,054

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2.3.1 Trends in the Sound Transmission for CFS-Framed Floors
The three sets of floor assemblies evaluated had the CFS joists spaced 406 mm on centers, and all had
resilient channel spacing of 406 mm on centers or less. These common features of the floors rule out
demonstrating the acoustical benefits of changing these parameters, but are common features inpractice to ensure adequate fire resistance.
Figure 2.3.2 compares the sound transmission loss observed for one floor from each set of test
specimens. These were chosen to provide the most consistent cases.

Figure 2.3.2:
Sound transmission loss for one
floor from each set of test
specimens. The floors differ in joist
depth and the details of the floor
deck, but the other features(spacing of the joists and resilient
channels, absorption in the cavity,
layers of gypsum board) are similar.

Effect of Subfloor
The most obvious difference between the specimens in the figure is that the floor with a thicker deck ofregular concrete (CON40) has significantly higher sound transmission loss across the whole frequency
range, despite having the joists with the smallest depths. The combination of the 25% thicker concrete
layer and the 16% higher density of the concrete (2260 kg/m3 for regular concrete compared to1950 kg/m3 for gypsum concrete) gives a significant increase in the mass per area and hence higher
sound transmission loss for the top surface. This is augmented slightly by improvements due to thinnersteel of the joists and larger spacing between the resilient channels, but the mass per area of the top
surface is the primary factor.

Effect of Gypsum Board Layers
Changing from 1 to 2 layers of 15.9 mm fire-resistant gypsum board on the ceiling consistently increased
the STC rating by about 4 points. The typical change in sound transmission loss as a function of
frequency roughly matched that shown in Figure 2.2.3 for wall specimens: an improvement of about 5
or 6 dB at the low and high frequencies and a broad dip between.
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Chapter 2: Sound Transmission through CFS-Framed Walls and Floors

Effect of Cavity Absorption
As in the case of CFS-framed walls, the depth and the type of sound absorbing material in the cavities
between the framing members is also a factor that should be considered. Figure 2.3.3 shows the effectof changing the sound absorbing material in a set of floors that are otherwise identical.

Figure 2.3.3:
Sound transmission loss for a set offloors that are identical except for
the amount and type of soundabsorbing material in the spaces
between joists. Note that thetransmission loss results withadded absorption are significantly
higher than the transmission loss
results for the empty cavity.

The addition of sound absorbing material between the floor joists has a significant effect on the STC
rating of the floor assembly:

Adding 90 mm of absorption (filling about 40 % of the cavity volume) increases the STC rating by
6 from 62 for the empty cavity to 68 after adding the absorbing glass fiber or mineral fiber batts.
Increasing the depth of the absorption to 200 mm (which nearly fills the cavity) increases the
STC rating by 2 more to 70.
The overall increase due to filling the cavity with absorption (+8) is very similar to the increase in
STC rating observed when the layers of gypsum board are doubled.

The effect of using different types of sound absorbing material is small. For the floors in Figure 2.3.3,
the glass fiber batts and mineral fiber batts resulted in nearly identical transmission loss values. The
figure shows that the curves are almost identical above 125 Hz. The use of cellulose fiber resulted in ahigher transmission loss, but this improvement is best ascribed to the thickness of the CFL200 batts
which filled 90% of the cavity (versus 40% for the glass fiber and mineral fiber batts). This interpretation
is supported by the observations that floor CFS-J203-F05 with 120 mm of cellulose fiber (not plotted)
had the same STC rating as the walls with 90 mm glass fiber or mineral fiber batts. As for the walls
presented in Section 2.2, this study suggests no significant change in the STC rating due to the type ofsound absorbing material.

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Effect of Cavity Depth
Comparison studies were performed between a CFS-framed floor with a joist depth of 254 mm and anominally identical CFS-framed floor with a joist depth of 317 mm. The STC ratings for the two floors
differed by 0 to 1 points, and the transmission loss values were generally within ±3 dB. For these cases it
was therefore concluded that the cavity depth does not significantly influence the sound insulation.

Effect of Floor Finishes
When floor finishes were added over the gypsum concrete subfloor surfaces, an appreciable change insound transmission loss was observed, as presented in Figure 2.3.4.

Figure 2.3.4:
Change in sound transmission loss
ΔTL due to addi g floor finishes
over the bare subfloor of the floors
with gypsum concrete surface. In
each plot, the mean change isshown by a solid line.
The upper graph shows the changes
due to adding laminate flooring(ΔTL-CFS-F02 in Table 2.3.2) on four
floors. The changes are very similar
except above 2 kHz, and thechanges in STC were consistent.
The lower graph shows the changes
due to adding carpet and underlay(ΔTL-CFS-F03 in Table 2.3.2) on two
floors. The changes are very similar
except above 2 kHz, and thechanges in STC rating were similar.

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Chapter 2: Sound Transmission through CFS-Framed Walls and Floors
Figure 2.3.5 presents the mean change in sound transmission loss observed for the three types of floor
finishes that were tested on these floors.

Figure 2.3.5:
Mean change in the soundtransmission loss ΔTL due to the 3types of floor finishes added overthe bare gypsum concrete floor
surfaces.
Note that despite the large
increases at the higher frequencies
for carpet and laminate flooring,the increase in the STC rating issmall, because the STC ratings arelimited by the low frequency
performance of the floor.

The effects of the floor coverings on the impact insulation class (IIC) are greater than for the STC rating,but the impact noise insulation is out of the scope of this edition of the Report.

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

3 Flanking Sound Transmission in CFS-Framed Constructions
The focus of this chapter is the experimental testing conducted on a series of building mock-ups
comprising CFS-framed walls connected to CFS-framed floors. ISO 15712-1 [7] provides a procedure forpredicting sound transmission in buildings where the structure is composed of connected homogeneous
wall and floor assemblies. CFS-framed constructions do not fall within this scope.
The same basic concept of combining the sound power transmitted via direct and flanking paths does
apply to CFS-framed assemblies, but different test methods are required to evaluate flanking paths.
Instead of using the procedures of ISO 15712-1, which are appropriate only for heavy homogeneous
constructions, experimental data from measurements following the procedures of ISO 10848 [6] areused to characterize the flanking transmission for CFS constructions.

3.1

Test Facility and Procedures for CFS-Framed Assemblies

This introduction provides a brief description of the setup and standardised test methods used tomeasure flanking sound transmission loss values for specific structure-borne transmission paths in CFSframed assemblies.
Measurements were conducted in the fully-automated 8-room flanking sound transmission facility at
the NRC, depicted in Figure 3.1.1. Each room in the facility is equipped with four loudspeakers withindependent/incoherent sources and one microphone that can be positioned by a robot at a set of
selected positions for each test sequence. The test specimen consists of eight walls, four floors, and six
junctions. The permanent shell of the facility (upper ceiling/roof, perimeter walls, and foundation floor)
is constructed of highly sound insulating elements that are resiliently isolated from each other and fromthe test specimens, with vibration breaks in the permanent surfaces where the specimens are installed.
The upper rooms have a ceiling height of 2.7 m while the lower rooms have a height of 2.4 m. The
volume of the rooms used to assess flanking transmission in this study ranged between 34 m3 and 53 m3.
Specimens are installed with the loadbearing walls under a hydraulic loading system, which permits
simulation of buildings more than 2 stories in height.
The individual flanking paths between adjacent rooms (horizontally and vertically separated) were
determined following the indirect method described in ISO 10848. Sound transmission loss
measurements were conducted in both directions and the average was used as the final result. This
procedure reduces errors associated with the microphone calibration. For each room pair, the source
room was excited with pink noise using the four uncorrelated loudspeakers in that room. The soundpressure levels were recorded in the source room and the other seven rooms at nine positions each,using a microphone which was moved by a computer-controlled robot in each room. The reverberation
times were measured using the interrupted noise method as specified in ASTM E2235 [3]. Backgroundnoise levels were measured in each room as part of the transmission loss measurements. The impact
sound insulation of the specimen was also tested using the standard tapping machine and the heavy soft
rubber ball, but those results are out of the scope of this edition of the Report.
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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Figure 3.1.1(a): Schematic representation of a
specimen installed in the 8-room flanking facility

Figure 3.1.1(b): The interior of the flanking facility
before construction of the specimen.

Determining Flanking TL for Individual Transmission Paths
In many cases, the flanking path of interest could be measured directly by shielding all other paths
between the rooms. The wall shielding consisted of two layers of 15.9 mm gypsum board which were
installed in front of the specimen surface without any structural connection (i. e. the shielding was
supported by the permanent facility floor or ceiling instead of being attached to the test specimen). The
120 mm deep cavity between the shielding layers and the specimen surface was filled with fibrousinsulation, and the perimeter was sealed with tape. Tests showed that this type of wall shielding
provided an additional transmission loss between 15 dB and 25 dB over most of the frequency range ofinterest when installed on both sides of the wall.
In the upper rooms, floor shielding consisted of two layers of 16 mm plywood held together withacoustic dampening glue and supported on 70 mm thick mineral fiber board. The additionaltransmission loss provided by the shielding layers was insufficient for evaluating the wall paths in theupper rooms. For this reason, the wall paths from the lower rooms are considered to be more reliable
than the wall paths from the upper rooms, and were used to assess wall-wall paths.
In some cases, it was necessary to extract the flanking path of interest from a set of measurements withdifferent shielding conditions. For example, the ceiling surfaces in the lower rooms could not be shielded
due to the practical difficulties of suspending the shielding layers without structurally connecting themto the specimen. As a consequence, the ceiling-ceiling path is always included in any measurement
between horizontally adjacent lower rooms. In order to determine the direct path through a separatingwall in the lower rooms, it was therefore necessary to first determine the ceiling-ceiling path and thewall-ceiling and ceiling-wall paths. The sound power of these three paths was then removed from thePage 30 of 102

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions
apparent transmission, yielding the direct path through the separating wall. Throughout this procedure
it was important to take proper account of flanking limits and background noise.

Effect of Structural Loading
Normally the tests were conducted with an axial load of approximately 5000 lbs applied to the top of
the loadbearing wall, but a comparison was made between data measured both with and without theload. The apparent transmission loss of the loadbearing walls without loading is about 2 dB higher
above 315 Hz than with load, but within 0.5 dB below that frequency. For all other paths the change due
to removing loading was less than 0.5 dB. Generally, the configuration without loading has a slightly
higher transmission loss, but the ASTC ratings are all within 1 point. Thus vertical loading has only aminor influence on the measured transmission loss values, and the normal test procedure with loading
can be regarded as providing a slightly conservative estimate.

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

3.2 Description of Flanking Specimen
Figure 3.2.1 shows some images of the specimen during construction.
Figure 3.2.1: Some images of the CFS-framed
assemblies under construction.
The flanking test specimen consisted of four
loadbearing walls, four non-loadbearing
walls, four floors, and six junctions, which
divide the space into 8 rooms.
To take advantage of symmetries and toallow for redundant measurements, each of
the four loadbearing walls was nominallyidentical in this study, as were the four nonloadbearing walls and the four floors.

1

The images show:
1. The top image shows early assemblyof the CFS framing for the lower
loadbearing walls and the CFS joists
for the floor-ceiling assemblies.
2. The middle image shows construction
after framing of the floor assembly
was complete, with some insulation
installed in the joist cavities.
3. The bottom image shows the floor
surface after installation of the
gypsum concrete with the upper
loadbearing walls in place in theforeground. Note the continuous
gypsum concrete through the framingon the left (loadbearing Junction LBc)
and the break in the gypsum concretesurface on the right (loadbearing
Junction LBd). The upper wall framing
for the non-loadbearing Junction
NLBd is visible in the back, looking
through the loadbearing wall. The
upper wall for the non-loadbearing
Junction NLBc was installed on top of
the gypsum concrete in the front.

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

3.2.1 Walls of CFS-Framed Flanking Specimen
The walls investigated in this study were double-leaf walls with one row of cold-formed steel studs asframing members. Using a short code to describe the various wall parameters (as in Sections 2.1 and2.2) the loadbearing walls were defined as follows: 2G16_SS152(406)_GFB152_RC13(406)_2G16. Here,
2G16 indicates two layers of 15.9 mm thick gypsum board2 (mass per area: 11.0 kg/m2 per layer),
SS152(406) indicates 152 mm deep steel studs1 spaced 406 mm on centers (steel thickness: 1.37 mm),
GFB152 indicates 152 mm thick glass fiber insulation3, and RC13(406) indicates 13 mm deep resilient
metal channels4 spaced 406 mm on centers. The gypsum board was attached with screws spaced
305 mm on centers at the perimeter and in the field. In addition to these elements, the loadbearing
walls also included bridging channels and steel straps for bracing against lateral and shear loads.
Figure 3.2.2 shows ahorizontal cross section(where the studs areperpendicular to theplane of the drawing) of
typical construction forthe loadbearing and nonloadbearing wall
assemblies.
The non-loadbearing walls in this study were very similar to the loadbearing walls, except for thefollowing changes:
 The non-loadbearing studs were formed from steel with a thickness of 0.54 mm.
 Stud depth and cavity insulation thickness were reduced from 152 mm to 92 mm.
 The non-loadbearing CFS studs were inserted into the upper track but not screwed to it. The
studs were fixed in position by the gypsum board which was screwed to the studs.
 The non-loadbearing walls did not include bridging channels and bracing steel straps, but aredescribed using a similar short code as 2G16_SS92(406)_GFB92_RC13(406)_2G16.

3.2.2 Floors of CFS-Framed Flanking Specimen
The floors investigated in this study consisted of lightweight gypsum concrete with an average thicknessof 32 mm on a corrugated steel deck, fastened to steel joists with a gypsum board ceiling. Using a shortcode to describe the various floor parameters (as in Sections 2.1 and 2.3), the floor assembly wasdefined as the following: GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16. Here, GCON32
indicates a layer of lightweight gypsum concrete with an average thickness of 32 mm (maximum
thickness of 38 mm measured from the bottom of the corrugated steel deck). The gypsum concretedensity was 1950 kg/m3, which gave an average mass per unit area on the corrugated steel deck ofApparent Sound Insulation in CFS-Framed Buildings
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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions
60 kg/m2. The gypsum concrete was poured onto the steel deck in-situ, and was left to cure for morethan a month before testing. The strength of the cured gypsum concrete was 24.8 MPa.
CORSTE14 indicates the corrugated steel deck (depth of corrugation: 14 mm, steel thickness: 0.76 mm),and SJ254(406) indicates 254 mm deep steel joists1 spaced 406 mm on centers (steel thickness:
1.37 mm). The floor also included blocking strips, installed at the center of the joists between the twolast joists on each end and between the two joists in the floor center, and a steel strap connecting thethree blocking strips with each other and with the other joists. The corrugated steel deck was fastened
to the joists with screws spaced 203 mm on centers. As before, GFB92 indicates 92 mm thick glass fiber
batts3, RC13(305) indicates 13 mm deep resilient metal channels4 spaced 305 mm on centers, and G16
indicates one layer of 15.9 mm thick gypsum board2. The gypsum board was attached with screws
spaced 305 mm on centers at the perimeter and in the field. The glass fiber insulation batts were restingon the resilient metal channels. A cross-section of one of the floor assemblies is shown in Figure 3.2.3.
Figure 3.2.3 shows a vertical cross section (plane of the drawing is parallel to the joists) of theconstruction details for the floor assemblies used in the flanking sound transmission tests.

3.2.3 Junctions of the CFS-Framed Flanking Specimen
The four horizontal wall/floor junctions were chosen to represent a variety of junction details
encountered in practice. Table 3.2.1 summarizes some key features of these junction configurations
which are described in more detail below.
Table 3.2.1

Walls

Joist Orientation

JoistsSubfloor

Junction LBc

Loadbearing

Perpendicular to junction

Continuous

Continuous

Junction LBd

Loadbearing

Perpendicular to junction

Discontinuous Discontinuous

Junction NLBd

Non-Loadbearing

Parallel to junction

N/A

Discontinuous

Junction NLBc

Non-Loadbearing

Parallel to junction

N/A

Continuous

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Loadbearing Junction LBc
The LBc junction connected the loadbearing CFS-framed walls with CFS-framed floors whose joists wereperpendicular to the junction and continuous across the junction. The floor deck was essentiallycontinuous.







The CFS floor joists1 were supported on the top track of the lower loadbearing wall, and thebottom track of the upper loadbearing wall was supported on the top of the floor joists. A shortstud segment was fastened to each joist to stiffen it at the junction. The floor and wall framing
were screwed together at their intersections.
The corrugated steel deck was installed after the loadbearing walls and the floor joists, andended at the wall framing. Gypsum concrete was installed on the floor deck, filling the bottom
track of the upper loadbearing wall to create a gypsum concrete floor deck that is essentiallycontinuous (interrupted only by the embedded bottom track of the upper loadbearing wall).
The gypsum concrete was bonded to the surfaces of the deck and the track of this upper
loadbearing wall.
Details of the wall and floor assemblies are given in Sections 3.2.1 and 3.2.2.
Different configurations of Junction LBc were tested in this study, including with and without fire
blocks in the joist cavities, and with one or two layers of gypsum board on the ceiling.

Figure 3.2.4 shows a verticalcross section (joists areparallel to the plane of thedrawing) of the construction
details for the loadbearing
wall/floor Junction LBc.
Note that both the floor joists
and the gypsum concrete deckare continuous across thejunction.
Drawing is approximately toscale. This junction was also
called the East junction insome previous publications.

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Loadbearing Junction LBd
The LBd junction connected the loadbearing CFS-framed wall with CFS-framed floors whose joists wereperpendicular to the junction, but not continuous across the junction. The composite floor deck of
gypsum concrete on a corrugated metal pan was also discontinuous.








The end frame of the CFS floor was attached to the top of the lower loadbearing wall so that the
top of the joists aligned with the top of the lower wall. Then the CFS floor joists1 were attachedto the end frame and the loadbearing studs using joist hangers. Note that the CFS end frames
on both sides of the loadbearing wall completely block the spaces between the joists, thus
providing a fire block and suppressing airborne flanking via the joist cavities.
The bottom track of the upper loadbearing wall was supported on top of the lower wall framing.
The corrugated steel deck was installed after the loadbearing walls and the floor joists, andended at the wall framing. Gypsum concrete was installed on the floor deck, but did not fill thebottom track of the upper loadbearing wall, so that the subfloor between the two upper rooms
was structurally disconnected. The gypsum concrete was bonded to the surfaces of thecorrugated steel deck and to the outer faces of the track of the upper wall.
Details of the wall and floor assemblies are given in Sections 3.2.1 and 3.2.2.
Different configurations of Junction LBd were tested in this study, including with one or twolayers of gypsum board on the ceiling.

Figure 3.2.5 shows a verticalcross section (joists areparallel to the plane of thedrawing ) of the construction
details for the loadbearing
wall/floor Junction LBd.
Note that both the floor joists
and the gypsum concrete deckare discontinuous across thejunction.
Drawing is approximately toscale. This junction was also
alled the West ju tio isome previous publications.

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Non-Loadbearing Junction NLBc
The NLBc junction connected the non-loadbearing CFS-framed walls with CFS-framed floors whose joists
were oriented parallel to the junction. The floor deck was installed before the upper non-loadbearing
wall, and was continuous across the junction.









An assembly of 4 CFS floor joists1 was positioned at the wall/floor junction. Two joists were
faste ed togethe to fo a o , hi h as filled ith sou d absorbing material; this pair ofjoists supported the floor deck above, and the top track of the lower non-loadbearing wall was
fastened to their bottom surface. A othe joist as faste ed to ea h fa e of the o a d theseprovided support for the ends of the resilient metal channels supporting the ceiling below.
The upper non-loadbearing wall was standing on top of the gypsum concrete floor deck
assembly at the junction. This wall assembly was installed after the corrugated steel deck andgypsum concrete were added to form the floor deck. The gypsum concrete was bonded to thecorrugated steel deck and the bottom track of the upper wall was fixed to the subfloor deck.
The upper track of the lower non-loadbearing wall was screwed to the underside of the joists
above. The non-loadbearing CFS studs1 were inserted into the upper track but not screwed to it;
the studs were fixed in position by the gypsum board which was screwed to the studs.
Details of the wall and floor assemblies are given in Sections 3.2.1 and 3.2.2.
Different configurations of Junction LBd were tested in this study, including with one or twolayers of gypsum board on the ceiling.

Figure 3.2.6 shows a verticalcross section (joists areperpendicular to the plane ofthe drawing) of theconstruction details for the
non-loadbearing wall/floor
Junction NLBc.
Note that the gypsum
concrete deck is continuous
across the junction.
Drawing is approximately toscale. This junction was also
alled the No th ju tio isome previous publications.

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Non-Loadbearing Junction NLBdThe NLBd junction connected the non-loadbearing CFS-framed walls with CFS-framed floors whose joists
were oriented parallel to the junction. The floor deck was discontinuous.









An assembly of 4 CFS floor joists1 was positioned at the wall/floor junction. Two joists were
faste ed togethe to fo a o , hi h as filled ith sou d absorbing material; this pair ofjoists supported the non-loadbearing wall above, and the track of the lower non-loadbearing
all as faste ed to thei otto su fa e. A othe joist as faste ed to ea h fa e of the oand these provided support for the edge of the floor deck above and for the ends of the resilient
metal channels supporting the ceiling below.
The upper non-loadbearing wall was built directly on top of the floor joist assembly at thejunction. This wall assembly was installed before the corrugated steel deck and gypsum concrete
were added to form the floor deck, so the floor deck ended at the outer faces of its bottom
track. Although this configuration is not often found in practice, it was chosen to allow theinsertion of vibration breaks in the subfloor.
The lower non-loadbearing wall terminated at the bottom of the joists. The upper track wasscrewed to the underside of the joists, and the non-loadbearing CFS studs1 were inserted into
the upper track but not screwed to it; the studs were fixed in position by the gypsum board.
Details of the wall and floor assemblies are given in Sections 3.2.1 and 3.2.2.
Different configurations of Junction LBd were tested in this study, including with one or twolayers of gypsum board on the ceiling.

Figure 3.2.7 shows a verticalcross section (joists areperpendicular to the plane ofthe drawing) of theconstruction details for the
non-loadbearing wall/floor
Junction NLBd.
Note that the gypsum
concrete deck is discontinuous
across the junction.
Drawing is approximately toscale. This junction was also
alled the “outh ju tio isome previous publications.

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Wall/Wall Junctions (LB or NLB)
The two vertical wall/wall junctions (in the upper and lower rooms) in this specimen were essentially
mirror images. Figure 3.2.8 shows a top view of the wall-wall junction. If a loadbearing wall separates
the side-by-side rooms of interest the wall/wall ju tio is desig ated LB . If a non-loadbearing wall is
the sepa ati g asse l the ju tio is desig ated NLB .








The loadbearing walls (left to right in Figure 3.2.8) and the floors were framed first. An assemblyof two loadbearing CFS studs was positioned at the wall/wall ju tio to fo a o , hi h
was filled with sound absorbing material and had a slight gap between the two studs forvibration isolation. Clips fastened to the loadbearing studs provided support for the ends of theresilient metal channels, and 65 mm wide metal tracks supported the edge of the directly
attached gypsum board on the other side of the wall.
The non-loadbearing wall assembly on each side was installed after the loadbearing wall, withthe closest non-loadbearing stud about 10
f o the o of load ea i g studs.
The gypsum board on each wall was directly attached to one side of the studs and supported on
resilient channels on the other. The resilient channels were always attached first, then the
directly attached gypsum board sheets, and then the gypsum board supported on the resilient
channels (butting against the directly attached gypsum board).
Details of the wall assemblies are given in Section 3.2.1.
Different configurations of the wall/wall junction were tested in this study, including with one or
two layers of gypsum board attached to the resilient channels on the walls.

Figure 3.2.8 shows a horizontal crosssection (studs are perpendicular tothe plane of the drawing) of theconstruction details for the wall/wall
junctions.
The drawing is approximately toscale. This is a top view of the wall
assemblies separating the lower
rooms; the configuration for theupper floor is identical.
If a loadbearing wall separates the
side-by-side rooms of interest theall/ all ju tio is desig ated LB .
If a non-loadbearing wall is theseparating assembly the junction isdesig ated NLB .

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

3.3 Tested Junctions of CFS-Framed Floors with Walls
The following tables present values of the flanking sound transmission via specific paths that were
determined from measurements following the procedures of ISO 10848 on a series of mock-up
constructions with connected CFS-framed floor and wall assemblies. The facilities and test proceduresare described in Section 3.1. The test specimens are described in Section 3.2.
This chapter focusses on single-number results for the flanking sound transmission as was done for thepresentation of the STC and Δ“TC results in Chapter 2. In this case, the results are values of flanking
sound transmission class (Flanking STCij), where the subscript i denotes the source room (surface D or F),
and the subscript j denotes the connected receiving room (surface d or f) for the transmission paththrough the junction. These values are used to calculate the ASTC rating in the examples in Chapter 4
which are calculated using the Simplified Method of ISO 15712-1.
Tables 3.3.3.1 to 3.4.4.3 show the Flanking STC values for a set of paths through a junction. Each tableconsists of several parts:
1. A brief generic description of details of the wall and floor/ceiling assemblies and the junctions
where they connect (a summary of the more complete descriptions provided in Section 3.2).
2. A drawing showing the general features of the junction.
3. Each cross-junction of walls with floor/ceiling assemblies can be viewed in several ways:(a) as the wall-floor junction between two side-by-side rooms above the floor;(b) as the wall-ceiling junction between two side-by-side rooms below the ceiling; and(c) as the junction of a flanking wall with the floor/ceiling assembly separating two rooms thatare one-above-the-other.
4. Junction cases (a) to (c) are presented in the rows below, with stylized drawings to identify thepaths in each case and Flanking STC values for each flanking path ij.
Junction naming follows a simple coding system in four segments:
 The first segment of the code indicates that the junction consist of CFS-framed assemblies.
 The second segment of the code indicates the junction type:> WF = wall/floor,> WC = wall/ceiling,> FW = floor/wall, The third segment of the code indicates which of the basic junctions from Section 3.2 is used.
 The fourth segment of the code is the unique number for that junction detail.

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

NOTE:
All the Flanking STC results in this chapter have been normalized to the Standard Scenario presented
in Chapter 1, using Equation 4.1.3. The test results presented in the tables in this Section include:(a) Values of Flanking STC measured following the procedures of ISO 10848-3 for rooms that are
side-by-side (i. e. a wall is the separating assembly), normalized to S = 12.5 m2 and l = 5 m forthe wall/floor or wall/ceiling junction;(b) Values of Flanking STC measured following ISO 10848-3 for rooms that are one-above-theother (i. e. a floor/ceiling is the separating assembly), normalized to S = 20 m2 and l = 5 m; and(c) Values of STC measured according to ASTM E90 (as tabulated in Sections 2.2 and 2.3) for pathDd, in lieu of the measured Flanking STC for the same path.

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.3.1.1: Floor-Wall Transmission Paths
Loadbearing wall assembly:
 2G16_SS152(406)_GFB152_RC13(406)_2G16
 CFS framing formed from steel 1.37 mm thickFloor/Ceiling assembly:
 GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
Junction of wall with floor/ceiling assembly: Junction LBc without fire block CFS floor joists perpendicular to the loadbearing walland continuous across the junction
 Gypsum concrete subfloor continuous across junction
 Warning: This design without fire block does notcontrol smoke or fire spread at the junction.

Floor-Wall Junction LBc. Vertical section,
drawn approximately to scale.

(Complete description of Junction LBc in Section 3.2.)

Path

STCij

CFS-WF-LBc-11

Dd

58

Wall-Floor
Loadbearing Junction

Ff

48

Fd

49

Df

50

CFS-WC-LBc-11

Dd

58

Wall-Ceiling
Loadbearing Junction

Ff

62

Fd

60

Df

64

Dd

57

Ff

67

Fd

71

Df

72

Dd

57

Ff

67

Fd

69

Df

65

CFS-FW-LBc-11r
Floor-Wall
Loadbearing Junction(Wall gypsum board on
resilient channels)

CFS-FW-LBc-11d
Floor-Wall
Loadbearing Junction(Wall gypsum board
attached directly)

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.3.1.2: Floor-Wall Transmission Paths(same as 3.3.1.1 except 2nd layer of G16 removed on walls
where gypsum board is mounted on resilient channels)
Loadbearing wall assembly:
 2G16_SS152(406)_GFB152_RC13(406)_G16
Floor/Ceiling assembly:
 GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
Junction of wall with floor/ceiling assembly: Junction LBc without fire block CFS floor joists perpendicular to the loadbearing walland continuous across the junction
 Gypsum concrete subfloor continuous across junction
 Warning: This design without fire block does notcontrol smoke or fire spread at the junction.

Floor-Wall Junction LBc. Vertical section,
drawn approximately to scale.

(Complete description of Junction LBc in Section 3.2.)

Path

STCij

CFS-WF-LBc-12

Dd

54

Ff+Fd+Df≥44

CFS-WC-LBc-12

Dd

54

Wall-Ceiling
Loadbearing Junction

Ff

62

Fd

60

Df

69

Dd

57

Ff+Fd+Df

≥

Dd

57

Ff

67

Fd

69

Df

65

IICij

Wall-Floor
Loadbearing Junction

CFS-FW-LBc-12r
Floor-Wall
Loadbearing Junction(Wall gypsum board on
resilient channels)

CFS-FW-LBc-12d
Floor-Wall
Loadbearing Junction(Wall gypsum board
attached directly)

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.3.1.3: Floor-Wall Transmission Paths(same as 3.3.1.2 except fire block installed in the floor
cavities where the floor joists cross the loadbearing wall)
Loadbearing wall assembly:
 2G16_SS152(406)_GFB152_RC13(406)_G16
Floor/Ceiling assembly:
 GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
Junction of wall with floor/ceiling assembly: Junction LBc with fire block in joist cavities
 CFS floor joists perpendicular to the loadbearing walland continuous across the junction
 Gypsum concrete subfloor continuous across junction
 Fire block in floor cavities where floor joists cross wall

Floor-Wall Junction LBc. Vertical section,
drawn approximately to scale.

(Complete description of Junction LBc in Section 3.2.)

Path

STCij

CFS-WF-LBc-13

Dd

54

Wall-Floor
Loadbearing Junction

Ff

50

Fd

53

Df

55

CFS-WC-LBc-13

Dd

54

Wall-Ceiling
Loadbearing Junction

Ff

65

Fd

73

Df

69

Dd

57

CFS-FW-LBc-13r
Floor-Wall
Loadbearing Junction(Wall gypsum board on
resilient channels)

CFS-FW-LBc-13d
Floor-Wall
Loadbearing Junction(Wall gypsum board
attached directly)

Ff+Fd+Df

≥

IICij

*

Dd

57

Ff

67*

Fd

69*

Df

65*

(*) Estimates based on the assumption that the fire block has little influence on the vertical paths.
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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.3.1.4: Floor-Wall Transmission Paths(same as 3.3.1.3 except 2nd layer of G16 added to ceiling)
Loadbearing wall assembly:
 2G16_SS152(406)_GFB152_RC13(406)_2G16
 CFS framing formed from steel 1.37 mm thickFloor/Ceiling assembly:
 GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_2G16
Junction of wall with floor/ceiling assembly: Junction LBc with fire block in joist cavities
 CFS floor joists perpendicular to the loadbearing walland continuous across the junction
 Gypsum concrete subfloor continuous across junction
 Fire block in floor cavities where floor joists cross wall

Floor-Wall Junction LBc. Vertical section,
drawn approximately to scale.

(Complete description of Junction LBc in Section 3.2.)

Path

STCij

CFS-WF-LBc-14

Dd

54

Wall-Floor
Loadbearing Junction

Ff

50

Fd

53

Df

55

CFS-WC-LBc-14

Dd

54

Wall-Ceiling
Loadbearing Junction

Ff

76

Fd

77

Df

71

Dd

60

CFS-FW-LBc-14r
Floor-Wall
Loadbearing Junction(Wall gypsum board on
resilient channels)

CFS-FW-LBc-14d
Floor-Wall
Loadbearing Junction(Wall gypsum board
attached directly)

Ff+Fd+Df

≥

IICij

*

Dd

60

Ff

67*

Fd

≥

*

Df

≥

*

(*) Estimates based on the assumption that the fire block has little influence on the vertical paths.
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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.3.2.1: Floor-Wall Transmission Paths
Loadbearing wall assembly:
 2G16_SS152(406)_GFB152_RC13(406)_2G16
 CFS framing formed from steel 1.37 mm thickFloor/Ceiling assembly:
 GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
Junction of wall with floor/ceiling assembly: Junction LBd
 CFS floor joists perpendicular to the loadbearing wall
but not continuous across the junction
 Gypsum concrete subfloor not continuous across thejunction(Complete description of Junction LBd in Section 3.2.)

Floor-Wall Junction LBd. Vertical section,
drawn approximately to scale.

Path

STCij

CFS-WF-LBd-21

Dd58

Wall-Floor
Loadbearing Junction

Ff

65

Fd

62

Df

67

CFS-WC-LBd-21

Dd58

Wall-Ceiling
Loadbearing Junction

Ff

75

Fd

64

Df

70

Dd

57

CFS-FW-LBd-21r
Floor-Wall
Loadbearing Junction(Wall gypsum board on
resilient channels)

Ff

72

Fd

77

Df

75

CFS-FW-LBd-21d

Dd

57

Ff

65

Fd

72

Df

67

Floor-Wall
Loadbearing Junction(Wall gypsum board
attached directly)

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.3.2.2: Floor-Wall Transmission Paths(same as 3.3.2.1 except 2nd layer of G16 removed on walls
where gypsum board is mounted on resilient channels)
Loadbearing wall assembly:
 2G16_SS152(406)_GFB152_RC13(406)_G16
 CFS framing formed from steel 1.37 mm thickFloor/Ceiling assembly:
 GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
Junction of wall with floor/ceiling assembly: Junction LBd
 CFS floor joists perpendicular to the loadbearing wall
but not continuous across the junction
 Gypsum concrete subfloor not continuous across thejunction

Floor-Wall Junction LBd. Vertical section,
drawn approximately to scale.

(Complete description of Junction LBd in Section 3.2.)

Path

STCij

CFS-WF-LBd-22

Dd

54

Ff+Fd+Df≥

CFS-WC-LBd-22

Dd54

Wall-Ceiling
Loadbearing Junction

Ff

75

Fd

64

Df

70

Dd

57

Ff+Fd+Df

≥

Dd

57

Ff

65

Fd

72

Df

67

IICij

Wall-Floor
Loadbearing Junction

CFS-FW-LBd-22r
Floor-Wall
Loadbearing Junction(Wall gypsum board on
resilient channels)

CFS-FW-LBd-22d
Floor-Wall
Loadbearing Junction(Wall gypsum board
attached directly)

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.3.2.3: Floor-Wall Transmission Paths(same as 3.3.2.2 except 2nd layer of G16 added to ceiling)
Loadbearing wall assembly:
 2G16_SS152(406)_GFB152_RC13(406)_G16
 CFS framing formed from steel 1.37 mm thickFloor/Ceiling assembly:
 GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_2G16
Junction of wall with floor/ceiling assembly: Junction LBd
 CFS floor joists perpendicular to the loadbearing wall
but not continuous across the junction
 Gypsum concrete subfloor not continuous across thejunction(Complete description of Junction LBd in Section 3.2.)

Floor-Wall Junction LBd. Vertical section,
drawn approximately to scale.

Path

STCij

Dd

54

Ff+Fd+Df≥

CFS-WC-LBd-23

Dd54

Wall-Ceiling
Loadbearing Junction

Ff

83

Fd

≥

Df

74

Dd

60

Ff+Fd+Df

≥

Dd

60

Ff

65

Fd

≥

Df

≥

CFS-WF-LBd-23

IICij

Wall-Floor
Loadbearing Junction

CFS-FW-LBd-23r
Floor-Wall
Loadbearing Junction(Wall gypsum board on
resilient channels)

CFS-FW-LBd-23d
Floor-Wall
Loadbearing Junction(Wall gypsum board
attached directly)

Page 48 of 102

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.3.3.1: Floor-Wall Transmission Paths
Non-loadbearing wall assembly:
 2G16_SS92(406)_GFB92_RC13(406)_2G16
 CFS framing formed from steel 0.54 mm thickFloor/Ceiling assembly:
 GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
Junction of wall with floor/ceiling assembly: Junction NLBc
 CFS floor joists parallel to the non-loadbearing wall
 Gypsum concrete subfloor continuous across junction(Complete description of Junction NLBc in Section 3.2.)

Floor-Wall Junction NLBc. Vertical section,
drawn approximately to scale.

Path

STCij

CFS-WF-NLBc-31

Dd

57

Wall-Floor
Non-Loadbearing Junction

Ff

40

Fd

49

Df

50

CFS-WC-NLBc-31

Dd

57

Wall-Ceiling
Non-Loadbearing Junction

Ff

67

Fd

65

Df

71

Dd

57

Ff

72

Fd

76

Df

67

Dd

57

Ff

74

Fd

72

Df

67

CFS-FW-NLBc-31r
Floor-Wall
Non-Loadbearing Junction(Wall gypsum board on
resilient channels)

CFS-FW-NLBc-31d
Floor-Wall
Non-Loadbearing Junction(Wall gypsum board
attached directly)

Apparent Sound Insulation in CFS-Framed Buildings
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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.3.3.2: Floor-Wall Transmission Paths(same as 3.3.3.1 except 2nd layer of G16 removed on walls
where gypsum board is mounted on resilient channels)
Non-loadbearing wall assembly:
 2G16_SS92(406)_GFB92_RC13(406)_G16
 CFS framing formed from steel 0.54 mm thickFloor/Ceiling assembly:
 GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
Junction of wall with floor/ceiling assembly: Junction NLBc
 CFS floor joists parallel to the non-loadbearing wall
 Gypsum concrete subfloor continuous across junction(Complete description of Junction NLBc in Section 3.2.)

Floor-Wall Junction NLBc. Vertical section,
drawn approximately to scale.

Path

STCij

CFS-WF-NLBc-32

Dd

53

Wall-Floor
Non-Loadbearing Junction

Ff

40

Fd

49

Df

50

CFS-WC-NLBc-32

Dd

53

Wall-Ceiling
Non-Loadbearing Junction

Ff

67

Fd

65

Df

70

Dd

57

Ff+Fd+Df

63

Dd

57

Ff

74

Fd

72

Df

67

CFS-FW-NLBc-32r
Floor-Wall
Non-Loadbearing Junction(Wall gypsum board on
resilient channels)

CFS-FW-NLBc-32d
Floor-Wall
Non-Loadbearing Junction(Wall gypsum board
attached directly)

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.3.3.3: Floor-Wall Transmission Paths(same as 3.3.3.2 except 2nd layer of G16 added to ceiling)
Non-loadbearing wall assembly:
 2G16_SS92(406)_GFB92_RC13(406)_G16
 CFS framing formed from steel 0.54 mm thickFloor/Ceiling assembly:
 GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_2G16
Junction of wall with floor/ceiling assembly: Junction NLBc
 CFS floor joists parallel to the non-loadbearing wall
 Gypsum concrete subfloor continuous across junction(Complete description of Junction NLBc in Section 3.2.)

Floor-Wall Junction NLBc. Vertical section,
drawn approximately to scale.

Path

STCij

CFS-WF-NLBc-33

Dd

53

Wall-Floor
Non-Loadbearing Junction

Ff

40

Fd

49

Df

50

CFS-WC-NLBc-33

Dd

53

Wall-Ceiling
Non-Loadbearing Junction

Ff

76

Fd

≥

Df

≥

Dd

60

Ff+Fd+Df

≥

Dd

60

Ff

74

Fd

≥

Df

≥

CFS-FW-NLBc-33r
Floor-Wall
Non-Loadbearing Junction(Wall gypsum board on
resilient channels)

CFS-FW-NLBc-33d
Floor-Wall
Non-Loadbearing Junction(Wall gypsum board
attached directly)

Apparent Sound Insulation in CFS-Framed Buildings
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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.3.4.1: Floor-Wall Transmission Paths
Non-loadbearing wall assembly:
 2G16_SS92(406)_GFB92_RC13(406)_2G16
 CFS framing formed from steel 0.54 mm thickFloor/Ceiling assembly:
 GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
Junction of wall with floor/ceiling assembly: Junction NLBd CFS floor joists parallel to the non-loadbearing wall
 Gypsum concrete subfloor not continuous across thejunction(Complete description of Junction NLBd in Section 3.2.)

Floor-Wall Junction NLBd. Vertical section,
drawn approximately to scale.

Path

STCij

CFS-WF-NLBd-41

Dd57

Wall-Floor
Non-Loadbearing Junction

Ff

60

Fd

63

Df

67

CFS-WC-NLBd-41

Dd57

Wall-Ceiling
Non-Loadbearing Junction

Ff

77

Fd

70

Df

69

Dd

57

Ff

72

Fd

83

Df

82

Dd

57

Ff

72

Fd

76

Df

74

CFS-FW-NLBd-41r
Floor-Wall
Non-Loadbearing Junction(Wall gypsum board on
resilient channels)

CFS-FW-NLBd-41d
Floor-Wall
Non-Loadbearing Junction(Wall gypsum board
attached directly)

Page 52 of 102

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.3.4.2: Floor-Wall Transmission Paths(same as 3.3.4.1 except 2nd layer of G16 removed on walls
where gypsum board is mounted on resilient channels)
Non-loadbearing wall assembly:
 2G16_SS92(406)_GFB92_RC13(406)_G16
 CFS framing formed from steel 0.54 mm thickFloor/Ceiling assembly:
 GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
Junction of wall with floor/ceiling assembly: Junction NLBd CFS floor joists parallel to the non-loadbearing wall
 Gypsum concrete subfloor not continuous across thejunction

Floor-Wall Junction NLBd. Vertical section,
drawn approximately to scale.

(Complete description of Junction NLBd in Section 3.2.)

Path

STCij

CFS-WF-NLBd-42

Dd53

Wall-Floor
Non-Loadbearing Junction

Ff

60

Fd

63

Df

67

CFS-WC-NLBd-42

Dd53

Wall-Ceiling
Non-Loadbearing Junction

Ff

77

Fd

70

Df

69

Dd

57

Ff+Fd+Df

≥

Dd

57

Ff

72

Fd

76

Df

74

CFS-FW-NLBd-42r
Floor-Wall
Non-Loadbearing Junction(Wall gypsum board on
resilient channels)

CFS-FW-NLBd-42d
Floor-Wall
Non-Loadbearing Junction(Wall gypsum board
attached directly)

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.3.4.3: Floor-Wall Transmission Paths(same as 3.3.4.2 except 2nd layer of G16 added to ceiling)
Non-loadbearing wall assembly:
 2G16_SS92(406)_GFB92_RC13(406)_G16
 CFS framing formed from steel 0.54 mm thickFloor/Ceiling assembly:
 GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_2G16
Junction of wall with floor/ceiling assembly: Junction NLBd CFS floor joists parallel to the non-loadbearing wall
 Gypsum concrete subfloor not continuous across thejunction

Floor-Wall Junction NLBd. Vertical section,
drawn approximately to scale.

(Complete description of Junction NLBd in Section 3.2.)

Path

STCij

CFS-WF-NLBd-43

Dd53

Wall-Floor
Non-Loadbearing Junction

Ff

60

Fd

63

Df

67

CFS-WC-NLBd-43

Dd53

Wall-Ceiling
Non-Loadbearing Junction

Ff

80

Fd

72

Df

≥

Dd

60

Ff+Fd+Df

≥

Dd

60

Ff

72

Fd

≥

Df

≥

CFS-FW-NLBd-43r
Floor-Wall
Non-Loadbearing Junction(Wall gypsum board on
resilient channels)

CFS-FW-NLBd-43d
Floor-Wall
Non-Loadbearing Junction(Wall gypsum board
attached directly)

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

3.4 Tested Junctions of CFS-Framed Walls with Walls
The following tables present values of the flanking sound transmission via specific paths that were
determined from measurements following the procedures of ISO 10848 on a series of mock-up
constructions with connected CFS-framed wall assemblies. The facilities and test procedures aredescribed in Section 3.1. The test specimens are described in Section 3.2.
This chapter focusses on single-number results for the flanking sound transmission as was done for thepresentation of the STC and Δ“TC results in Chapter 2. In this case, the results are values of flanking
sound transmission class (Flanking STCij), where the subscript i denotes the source room (surface D or F),
and the subscript j denotes the connected receiving room (surface d or f) for the transmission paththrough the junction. These values are used to calculate the ASTC rating in the examples in Chapter 4
which are calculated using the Simplified Method of ISO 15712-1.
Tables 3.4.01 to 3.4.04 show the Flanking STC values for a set of paths through a junction. Each tableconsists of several parts:
1. A brief generic description of the details of the abutting wall assemblies and their junction.
2. A drawing showing the general features of the junction.
3. Junction cases are presented in the rows below, with stylized drawings to identify the paths ineach case, and Flanking STCij values for each flanking path ij.
4. Note that each junction of wall assemblies comprises the combination of a separating wall andtwo flanking walls. The separating wall could be a loadbearing wall, or a non-loadbearing wall. If
the separating wall is loadbearing, the flanking walls are non-loadbearing and vice versa.
5. The junction name is defined by the type of separating wall LB… o NLB… .
Junction naming follows a simple coding system in four segments:
 The first segment of the code indicates that the junction consists of CFS-framed assemblies.
 The second segment of the code indicates the junction type (WW=wall-wall).
 The third segment of the code indicates the nature of the junction itself:> the first letters (LB or NLB) indicates the type of separating wall,> the final letters (92, 152, etc.) indicates the stud depth for the separating wall
 The fourth segment of the code is the unique number for that junction detail.
Note 1. All the Flanking STC results in this chapter have been normalized to the Standard Scenariopresented in Chapter 1, using Equation 4.1.3.
Note 2. The test results in this section are for wall/wall junctions where the rooms are side-by-side,
separated by a wall assembly. Values are normalized to S = 12.5 m2 and l = 2.5 m.
Note 3. Although only cross-junctions were tested, a T-junction of wall assemblies should have thesame flanking sound transmission ratings as a cross-junction for CFS-framed wall assemblies.
Note 4. STC ratings measured according to ASTM E90 (from tables in Sections 2.2 and 2.3) are given for
path Dd in lieu of the measured Flanking STC for path Dd.

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.4.01: Wall-Wall Transmission Paths
Non-loadbearing wall assembly:
 2G16_SS92(406)_GFB92_RC13(406)_2G16
 CFS framing formed from steel 0.54 mm thickLoadbearing wall assembly:
 2G16_SS152(406)_GFB152_RC13(406)_2G16
 CFS framing formed from steel 1.37 mm thick
Junction:
 X-junction with closest studs of the non-loadbearing
walls spaced 10 mm from framing of loadbearing wall.
 If gypsum board on loadbearing wall is directly
attached to the framing, gypsum board on theadjacent non-loadbearing wall is supported on
resilient channels, and vice versa.

Wall-Wall Junction for CFS-framed
construction.

(Complete descriptions of these assemblies and junctions
with larger drawings are provided in Section 3.2.)

Horizontal section viewed from above,
drawn approximately to scale.

Path

Flanking STCij

Dd

58

Ff

82

Fd

76

Df

82

Dd

57

Ff

84

Fd

82

Df

81

CFS-WW-LB152-01
Wall-Wall Junction
with loadbearing
separating wall

CFS-WW-NLB92-01
Wall-Wall Junction
with non-loadbearing
separating wall

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.4.02: Wall-Wall Transmission Paths(same as 3.4.01 except 2nd layer of G16 removed on walls
where gypsum board is mounted on resilient channels)
Non-loadbearing wall assembly:
 2G16_SS92(406)_GFB92_RC13(406)_G16
 CFS framing formed from steel 0.54 mm thickLoadbearing wall assembly:
 2G16_SS152(406)_GFB152_RC13(406)_G16
 CFS framing formed from steel 1.37 mm thick
Junction:
 X-junction with closest studs of the non-loadbearing
walls spaced 10 mm from framing of loadbearing wall.
 If gypsum board on loadbearing wall is directly
attached to the framing, gypsum board on adjacentnon-loadbearing wall is supported on resilient
channels, and vice versa.
(Complete descriptions of these assemblies and junctions
with larger drawings are provided in Section 3.2.)

Wall-Wall Junction for CFS-framed
construction.
Horizontal section viewed from above,
drawn approximately to scale.

Path

Flanking STCij

Dd

54

Ff

82

Fd

76

Df

80

Dd

53

Ff

82

Fd

78

Df

81

CFS-WW-LB152-02
Wall-Wall Junction
with loadbearing
separating wall

CFS-WW-NLB92-02
Wall-Wall Junction
with non-loadbearing
separating wall

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.4.03: Wall-Wall Transmission Paths(same as 3.4.02 except resilient channels removed on
non-loadbearing separating wall and on loadbearing
flanking wall, and the directly attached gypsum board on
the flanking wall is continuous across the junction)
Non-loadbearing wall assembly:
 2G16_SS92(406)_GFB92_G16
 CFS framing formed from steel 0.54 mm thickLoadbearing wall assembly: G16_SS152(406)_GFB152_2G16 (left) and G16_SS152(406)_GFB152_RC13(406)_G16 (right)
 CFS framing formed from steel 1.37 mm thick
Junction:
 X-junction with closest studs of the non-loadbearing
walls spaced 10 mm from framing of loadbearing wall.
(Complete descriptions of these assemblies and junctions
with larger drawings are provided in Section 3.2.)

Wall-Wall Junction for CFS-framed
construction.
Horizontal section viewed from above,
drawn approximately to scale.

Path

Flanking STCij

Dd

43

Ff

48

Fd

62

Df

62

CFS-WW-NLB92-03
Wall-Wall Junction
with non-loadbearing
separating wall

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Table 3.4.04: Wall-Wall Transmission Paths(same as 3.4.03 except 2nd layer of G16 installed on theloadbearing flanking walls, directly attached to the studs
and continuous across the junction)
Non-loadbearing wall assembly:
 2G16_SS92(406)_GFB92_G16
 CFS framing formed from steel 0.54 mm thickLoadbearing wall assembly:
 2G16_SS152(406)_GFB152_2G16 (left) and 2G16_SS152(406)_GFB152_RC13(406)_G16 (right)
 CFS framing formed from steel 1.37 mm thick
Junction:
 X-junction with closest studs of the non-loadbearing
walls spaced 10 mm from framing of loadbearing wall.
(Complete descriptions of these assemblies and junctions
with larger drawings are provided in Section 3.2.)

Wall-Wall Junction for CFS-framed
construction.
Horizontal section viewed from above,
drawn approximately to scale.

Path

Flanking STCij

Dd

43

Ff

53

Fd

61

Df

66

CFS-WW-NLB92-04
Wall-Wall Junction
with non-loadbearing
separating wall

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

3.5 Trends in Flanking Sound Transmission for CFS-Framed Constructions
The evaluation of the flanking sound transmission in CFS-framed constructions included a wide range of
construction details. Flanking STC values for the tested configurations are presented in the tables in thepreceding sections for wall/floor and wall/wall junctions.
This section discusses the results for some of the cases to highlight the systematic changes in the
Flanking STC values due to specific changes in the construction details.
The discussion focuses on the following differences in the constructions: The effect of direction and continuity of the floor joists and of the subfloor; The effect of fire blocking of the floor cavities with Junction LBc;
 The effect of adding finish flooring on top of the floor-ceiling assemblies; The effect of adding layers of gypsum board to the ceilings;
 The effect of gypsum board continuity and attachment to the studs at wall/wall junctions.
These comparisons clearly identify construction details with the potential to significantly improve orworsen the flanking sound transmission.

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Effect of Continuous vs Discontinuous Joists and Subfloor
Flanking transmission is compared for Junction LBc vs. LBd (with floor joists perpendicular to theloadbearing separating wall) and then for NLBc vs. NLBd (with floor joists parallel to the non-loadbearing
separating wall). In each case, a pair of graphs shows floor-floor paths and then corresponding ceilingceiling paths, to illustrate changes in the flanking transmission loss due to differences in continuity of
the gypsum concrete deck and/or floor framing.

Figure 3.5.1:
Flanking sound transmission loss
for the floor-floor path Ff for aloadbearing wall/floor junction withjoists and subfloor continuous
across the junction (Junction LBc)
and for a loadbearing wall/floor
junction with joists and subfloor
discontinuous across the junction(Junction LBd).
Above 200 Hz, the transmission loss
for Junction Lbd is significantly
higher than for Junction LBc.
The corresponding changes in the ceiling-ceiling paths are shown in Figure 3.5.2. These changes arequite similar to those for the floor-floor paths, although slightly smaller.

Figure 3.5.2:
Flanking sound transmission loss
for the ceiling-ceiling path Ff for aloadbearing wall/ceiling junction
with joists continuous across thejunction (Junction LBc) and for aloadbearing wall/ceiling junction
with joists discontinuous across thejunction (Junction LBd).
Above 200 Hz, the transmission loss
for Junction Lbd is significantly
higher than for Junction LBc.

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Figure 3.5.3:
Flanking sound transmission loss
for the floor-floor path Ff for a nonloadbearing wall/floor junction with
continuous subfloor (Junction NLBc)
and for a non-loadbearing
wall/floor junction withdiscontinuous subfloor (Junction
NLBd).
The transmission loss is significantly
higher for Junction NLBd, due tothe discontinuity of the gypsum
concrete floor deck.
Figure 3.5.3 shows performance for the floor-floor paths at junction NLBc vs. NLBd, and corresponding
changes in the ceiling-ceiling paths are shown in Figure 3.5.4. The ceiling-ceiling path changes show
similar trends to those for the floor-floor paths, although the changes are much smaller, which is
expected since the construction differences are all associated with subassemblies above the floor joists.

Figure 3.5.4:
Flanking sound transmission loss
for the ceiling-ceiling path Ff for a
non-loadbearing wall/ceilingjunction with continuous subfloor(Junction NLBc) and for a nonloadbearing wall/ceiling junction
with discontinuous subfloor(Junction NLBd).
The transmission loss is higher for
Junction NLBd, due to discontinuityof the gypsum concrete floor deck,
although the change is smaller thanfor the floor-floor path.
Overall, it is clear that a subfloor which is continuous across the junction can cause serious flanking via
the floor-surfaces (especially path Ff). For Junction NLBc, the Flanking STC for the floor-floor path is 40,
significantly below a value at which occupant satisfaction can be expected. The Flanking STC value of 50
for Junction LBc is at the lower limit of acceptability, no matter how good the separating wall may be.
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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Effect of Fire Blocking in Floor Cavities
The fire block at the LBc junction is described in Section 3.2.

Figure 3.5.5:
Flanking sound transmission loss
for the floor-floor path Ff atwall/floor junction LBc with vs.
without a fire block at the junction.
For this junction, the floor joists areperpendicular to the loadbearing
separating wall and continuous
across the wall. Without a fire blockat the junction there is an open
cavity that provides an airborne
flanking path that decreases theapparent transmission loss.
Figure 3.5.5 shows that the performance for the floor-floor paths is only slightly changed by adding thefire block, but the Flanking STC rating does rise by 2 due to the increase between 200 and 2000 Hz.
Comparing this with Figure 3.5.6, the ceiling-ceiling path transmission loss increases more at mostfrequencies when the fire block is added, except for a small dip around 300 Hz that limits the
improvement in the Flanking STC rating to 3.

Figure 3.5.6:
Flanking sound transmission loss
for the ceiling-ceiling path Ff atwall/floor junction LBc with vs.
without a fire block at the junction.
For this junction, the floor joists areperpendicular to the loadbearing
separating wall and continuous
across the wall. Without a fire blockat the junction there is an open
cavity that provides an airborne
flanking path that decreases theapparent transmission loss.

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions
These changes in the floor-floor and ceiling-ceiling paths can make the difference between a junction
design that does not meet the ASTC 47 requirement of the NBCC (without the fire block), and a junction
design that does satisfy the ASTC 47 requirement, due to the added fire block. Of course the design
without the fire block also fails to satisfy the requirements for control of smoke and fire at the junction.
This provides an excellent example of how good design to control smoke and fire penetration across ajunction via hidden cavities tends to eliminate potentially problematic airborne flanking paths.

Effect of Adding Finish Flooring
The effect of adding finish flooring to the floors was presented in Section 2.3.1 for direct transmission
through the assembly. The corresponding effect for flanking paths involving the top surface of the floor
is shown in Figure 3.5.7. The effect on flanking paths is largest for the floor-floor flanking paths, and is
illustrated for Junction LBc in Figure 3.5.7. Similar improvements were measured for the other junctions.

Figure 3.5.7:
Flanking sound transmission loss
for the floor-floor path Ff atwall/floor junction LBc with a baregypsum concrete subfloor vs. thecase with finish flooring over the
gypsum concrete subfloor.

Figure 3.5.7 shows that performance for the floor-floor paths below 500 Hz is not significantly changedby adding the flooring, but the flanking transmission loss is increased appreciably at higher frequencies.
This result is consistent with the improvement in direct transmission loss through the floor-ceilingassembly shown in Figures 2.3.4 and 2.3.5. Note that the flanking transmission loss is limited at thehigher frequencies by the flanking limit of the test facility.
Although these flanking measurements were slightly affected by other paths, they are generally
consistent with the ΔTL measurements in Section 2.3.1 and justify using the latter in the ASTC
calculation examples in Chapter 4.

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Effect of Adding Gypsum Board Layers to Ceilings
Adding gypsum board to the ceilings increases not only the direct sound transmission loss for the floorceiling assembly (as shown in Section 2.3) but also the flanking transmission loss for paths including theceiling surfaces. Results for ceiling-ceiling paths Ff (where the effect is largest and most consistent) are
shown in Figures 3.5.8 and 3.5.9 for junctions LBc and NLBd, respectively.

Figure 3.5.8:
Flanking sound transmission loss
for the ceiling-ceiling path Ff atwall/floor junction LBc (joists
continuous across the junction)with a ceiling of one layer or twolayers of 16 mm thick gypsum
board on resilient channels.
Adding the second layer of gypsum
board is shown to increase the
Flanking STC rating by 11.

Figure 3.5.9:
Flanking sound transmission loss
for the ceiling-ceiling path Ff atwall/floor junction NLBd (joists
parallel to the junction) with aceiling of one layer or two layers of
16 mm thick gypsum board on
resilient channels.
Adding the second layer of gypsum
board is shown to increase the
Flanking STC rating by 3.

The two cases illustrated had the largest and smallest changes due to adding the second layer of gypsum
board. The Flanking STC rating increases of 8 and 9 for Junctions LBd and NLBc respectively wereintermediate between the illustrated cases.

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Effect of Gypsum Board Attachment at the Junction
The flanking transmission at the wall/wall junctions depends significantly on the way the gypsum board
is attached to the wall framing. Gypsum board that is continuous across the junction was shown todecrease the Flanking STC rating by about 30 points compared with gypsum board that is interrupted at
the junction.

Figure 3.5.10:
Flanking sound transmission loss
for the wall-wall path Ff at thewall/wall junction for different
variations of gypsum board
attachment to the loadbearing
flanking walls.
Gypsum board that is continuous
across the junction significantly
reduces the Flanking STC rating, by
about 30 STC points.

Figure 3.5.10 shows the transmission loss for the wall-wall flanking paths (path Ff) when the flanking
wall is loadbearing. The figure illustrates how continuous gypsum board on the flanking walls provides
an effective path for sound transmission between adjacent rooms. This can significantly affect theapparent sound insulation, independent of the design of the separating wall.

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

Summary of Trends in the Flanking Sound Transmission
The comparisons in Section 3.5 and the tabulated Flanking STC values in Sections 3.3 and 3.4 clearly
identify construction details with the potential to significantly improve or decrease the flanking
sound insulation:
 A break in the subfloor, for example by an intervening wall assembly without concrete filling thebottom track, can significantly reduce the flanking transmission via the floor surfaces. In thiscase study, the Flanking STC values for the floor-floor path for discontinuous subfloors were 15
points higher than for continuous subfloors in the case of a loadbearing junction, and 20 points
higher in the case of a non-loadbearing junction.
 For loadbearing junctions, the continuity of the joists affects both the flanking soundtransmission via the floor surfaces and the transmission via the ceiling surfaces. Joists that arecontinuous across the junction allow sound to travel uninterrupted, and hence should be
avoided if possible. In this case study, the Flanking STC values for the ceiling-ceiling path fordiscontinuous joists were 10 points higher than for continuous joists.
 Fire blocking is usually inserted into the joist cavities at the junction to control smoke and flame
spread, but it is also an efficient way to suppress airborne flanking transmission through thecavity. In this case study, the Flanking STC values for the floor-floor and ceiling-ceiling paths
increased by 2 and 3 points respectively when fire blocking was installed. Care should be taken
though to avoid additional rigid connections at the junction which could lead to higher
structure-borne sound transmission.
 Finish flooring on top of a floor-ceiling assembly has only a small effect on the flanking soundtransmission via the floor. For the cases tested, the Flanking STC values increased by 1-2 points.
Although the improvements are small for airborne sound insulation, the larger effect of flooringon impact sound insulation can significantly improve the overall acoustic performance.
 Adding a second layer of gypsum board to the ceiling was shown to improve the flanking
transmission for paths involving the ceiling. The Flanking STC values for the ceiling-ceiling paths
increased by 8-11 points for most junctions.
 Gypsum board that is installed continuous across a wall/wall junction can significantly decrease
the apparent sound insulation. When the gypsum board and wall studs were well-separated,
Flanking STC values above 80 were measured for the wall-wall path. When the gypsum board
was installed continuous across the junction, the Flanking STC values dropped to 48 and 53 forone and two layers of gypsum board respectively.

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Chapter 3: Flanking Sound Transmission in CFS-Framed Constructions

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Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

4 Predicting Sound Transmission in CFS-Framed Buildings
The focus of this chapter is to present the method for predicting the apparent sound transmission class(ASTC) rating between adjacent rooms in a building. The prediction method uses an empirical calculation
approach described in ISO 15712-1 [7] that combines laboratory sound transmission data for individual
CFS-framed wall or floor separating assemblies with flanking sound transmission data for each path attheir junctions with adjoining assemblies.
The transmission of structure-borne vibration in a building with lightweight framed structures (made ofwood or steel members) differs markedly from that in heavy homogeneous structures of concrete or
masonry. There is both good news and bad news:The good news: For lightweight framed assemblies, the high internal loss factors result inminimal dependence on the connection to the adjoining structures, so that laboratory soundtransmission values can be used without adjustment to estimate the direct transmission throughthe separating assembly in the finished building.
The bad news: The standardized method of calculating flanking sound transmission fromlaboratory sound transmission data for individual wall and floor assemblies combined withjunction attenuation data does not yield reliable results for lightweight framed building
elements, and a different approach is required. The calculation process explained below is very
simple (more good news), but it requires a new type of laboratory input data.

Before presenting the calculation process, some background justification seems appropriate. The
characteristic transmission of structure-borne vibration can be illustrated by considering the vibrationlevels in a framed floor assembly excited by a localized impact source, as presented in Figure 4.1.
Separatingwall

ImpactsourceFloorjoists70

100

Plan view offloor surface

94
96
98

92 88
86
76
80
82
72
70
78
68
74

70
66
66

Figure 4.1: Variation across the floor surface of the vibration levels (2 kHz band) due to an impact
source. The floor construction has a 19 mm plywood subfloor on wood joists that are perpendicular
to the separating wall between the two side-by-side rooms.
Clearly, the lightweight framed floor system is both highly damped and anisotropic – the vibration field
exhibits a strong gradient away from the source due to the high internal losses, and the gradient isApparent Sound Insulation in CFS-Framed Buildings
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Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings
different in the directions parallel and perpendicular to the joists, unlike the uniform flow of energy in all
directions that would be expected in a homogeneous cast-in-place concrete assembly. As a result, thedirection of transmission relative to the framing members becomes an additional parameter needed for
accurate prediction, and the transmission of sound power to or from a flanking surface is not simply
proportional to its area. In general, this vibration field is a poor approximation of a diffuse field, which
limits applicability of the energy flow model of ISO 15712-1 (which assumes homogeneous and lightlydamped assemblies that can be sensibly represented by an average vibration level).
Because of the attenuation across a flanking assembly, especially at higher frequencies, the assumptionthat sound power due to flanking is proportional to the flanking area (implicit in Section 4.1 ofISO 15712-1) is not appropriate. The equations in Section 4.1 of this Report provide more appropriate
normalization for highly-damped assemblies such as lightweight CFS-framed walls and floors.
Not only do vibration levels vary strongly across the surface of the structural assembly, but also typicalchanges to the surfaces (such as changing the gypsum board layers and/or their attachment to the walls
and ceiling) change the attenuation across the structural assembly, with different changes in the threeorthogonal directions pertinent to direct and flanking transmission. The change provided by a layer
added to a surface depends on the weight and stiffness of the surface to which it is added, and if theadded material is also anisotropic (for example, strip hardwood over a plywood subfloor) then its effectdepends on its orientation relative to the supporting framing.
Hence, the concept of a simple correction to account for adding a given lining is not generally applicablefor lightweight framed assemblies. However, the procedures presented in this Report do allow using
ΔTL a d Δ“TC o e tio s for floor finishes on a gypsum concrete subfloor, which is more reverberant.

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Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

4.1 Calculation Procedure for CFS-Framed Walls and Floors
The calculation process requires specific laboratory test data, and can be performed using frequency
band data or single-number ratings, following the steps illustrated in Figure 4.1.1.
The detailed calculation combines the set of one-third octave band transmission loss data for the direct
path and all flanking paths using Eq. 1.1 to arrive at values of the apparent sound transmission loss
(ATL). From the apparent sound transmission loss, the ASTC rating is calculated using the procedure of
ASTM E413 [3].

For CFS-framed assemblies, using the Simplified Method presented below should provide essentiallythe same answer as the Detailed Method (within ±1 ASTC points, with no bias). Hence the Simplified
Method is used for the following more complete description of the calculation procedure including
equations, and for the examples in Section 4.2.

Step 2a: For each edge of theseparating assembly, use Flanking TL
based on ISO 10848-3 tests for paths Ff,
Fd and Df (preferred), or the Flanking TL
due to this combination of paths.

Step 1a: For the
separating assembly, thein-situ TLDd equals the
TL measured in ASTM
E90 laboratory test.

Step 1b: If theseparating assemblyis a gypsum concrete
floor, add ΔTL
correction for added
finish flooring.

Step 3: Combine
Direct TLDd with
Flanking TL for the
12 flanking paths
to determine ATL.
Use ASTM E413 to
calculate ASTC.

ASTC

Step 2b: For each flanking path,
if any surface is a gypsum concrete floor,
add the ΔTL o e tio fo the additioof finish flooring. If the combination ofpaths Ff, Fd, Df is used in Step 2a, thelinings must be included in the whole
ju tioeasu e e ts a d o ΔTL
correction should be applied.

Figure 4.1.1: Steps to calculate the ASTC rating for lightweight CFS-framed constructions usingtransmission loss data. For the simplified procedure with STC ratings, su stitute “TC fo TL .
Step 1: (a) For the separating assembly, the in-situ STCDd is equal to the STC rating determined in thelaboratory according to ASTM E90.
(b) If the separating assembly is a floor with gypsum concrete surface, add the Δ“TC o e tio
for added floor finishes to the STC rating for the bare floor to obtain STCDd.

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Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings
Step 2: (a) Determine the Flanking STC values (STCFf, STCFd, STCDf) for the 3 flanking paths Ff, Fd and Df
at each edge of the separating assembly with the following adjustments:o Values measured following the procedures of ISO 10848-3 must be re-normalized to thescenario dimensions using Equation 4.1.3.
o If only the Flanking STC rating for the combined transmission by the set of 3 paths at ajunction is available, that data may be used.
(b) If one (or both) surface(s) for a flanking path is the gypsum concrete surface of a subfloor,
add the Δ“TC o e tio fo any added floor finish:o If o e su fa e i a fla ki g path is a g psu o ete su fa e of a su floo , add the Δ“TC fo
the added finish flooring to the value for the bare floor to obtain the Flanking STC rating.
o If both surfaces in a flanking path are gypsum concrete surfaces of a subfloor, the correction
e uals the la ge of the t o li i g Δ“TC o e tio s plus half of the lesse o e.
Step 3: Combine the transmission via the direct path and the 12 flanking paths using Equation 4.1.1(equivalent to Eq. 26 in Section 4.4 of ISO 15712-1), with the following adaptations:o If the Flanking STC rating calculated for any flanking path is over 90, set the value to 90.
o Round the final ASTC rating to the nearest integer.

Expressing the Calculation Process using Equations:
The ASTC rating between two rooms (neglecting sound transmitted by paths that bypass the building
structure, e. g. through leaks or ducts) is estimated in the Simplified Method from the logarithmic
expression of the combination of the Direct STC rating (STCDd) of the separating wall or floor element
and the combined Flanking STC ratings of the three flanking paths for every junction at the four edges ofthe separating element. This may be expressed as:

ASTC = −log[− . ⋅STC��

4

+ ∑ (
edge=

− . ⋅STC��+− . ⋅STC��+− . ⋅STC��

)]

Eq. 4.1.1

Eq. 4.1.1 is appropriate for all types of building systems with the geometry of the Standard Scenario, andis applied here using the following notes to calculate the sound transmission for each individual path:(a) If the separating assembly is a framed wall assembly, then the direct path STCDd is equal to thelaboratory STC rating for that assembly. Alternatively if the separating assembly is a floor with
gypsum concrete surface, add the Δ“TC o e tio fo any added finish flooring to the STC rating
for the bare floor to obtain STCDd for the direct path, as indicated in Eq. 4.1.2.
STC

Page 72 of 102= STC+ ΔSTC �

Eq. 4.1.2

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Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings(b) The options for the calculation of the Flanking STCij for each flanking path ij include:The procedures described in ISO 10848-3 yield experimental values of the normalizedflanking level difference Dnf. As per the standard, these Dnf values are normalized to anabsorption of 10 m2 in the receiving room. In order to convert the Dnf values to Flanking TLij
values, the correction term 10 log(Slab/10) is added, yielding values of Flanking TL normalized
to the room dimensions of the laboratory. When the laboratory values for Flanking TL or
Flanking STC are to be applied for a calculation scenario where the room dimensions aredifferent, they must be re-normalized to reflect room dimension differences between thelaboratory test rooms and the prediction scenario (indicated in Eq. 4.1.3 by the subscript
situ . The e p essio to use i the al ulatio is:

Flanking TL= Flanking TL�

+

log

/ �

+

log

�

/

in dB

Eq. 4.1.3

Here, Ssitu is the area (in m2) of the separating assembly and lsitu is the junction length (in m)
for the prediction scenario, and Slab and llab are the corresponding values for the specimen in
the ISO 10848 laboratory test. The Flanking STC rating may be determined using theprocedure of ASTM E413 with the one-third octave band values of Flanking TL as input data.



If one of the flanking ele e ts is a flooith g psu
o ete su fa e, add the Δ“TCcorrection for added floor finishes to the Flanking STCij for the bare floor to obtain the
Flanking STCij including the flooring.
Flanking STC= Flanking STC+ ΔSTC �

Eq. 4.1.4

If flanking elements i and j are both floor assemblies with gypsum concrete surfaces, andboth have added finish flooring, add the correction to the Flanking STCij for the bare floor as
in Eq. 4.1.5. Note, however, that lining corrections are not appropriate for CFS-framed
assemblies with surfaces other than gypsum concrete or concrete (such as OSB for floors or
gypsum board for walls).

Flanking STC= Flanking STC+ { ��(ΔSTC , ΔSTC ) +Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

� (ΔSTC , ΔSTC )}Eq. 4.1.5

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Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

4.2 Calculation Examples for CFS-Framed Walls and Floors
This section presents a number of worked examples that demonstrate the calculation of the ASTC rating
for CFS-framed constructions according to the Simplified Method described in Section 4.1. Each worked
example in this section presents all the pertinent physical characteristics of the assemblies andjunctions, together with a summary of key steps in the calculation process for these constructions.
U de the si gle headi g “TC, Δ“TC , the e a ples p ese t i put data deteaccording to ASTM E90, including:i ed i la o ato

tests

STC ratings for laboratory sound transmission loss data for wall and floor assemblies;
Δ“TC alues easu ed i the la o ato a o di g to ASTM E90 for the change in STC rating due
to adding floor finishes to the specified floor assembly (as discussed in Section 2.3);
Flanking STC values for each flanking path at each junction measured following ISO 10848 andre-normalized using Eq. 4.1.3.

U de the headi g A“TC , the e a ples p ese t the al ulated alues i ludi g:

Direct STC ratings for in-situ transmission through the separating assembly including linings;
Flanking STC ratings for each flanking transmission path including the change due to linings;
ASTC ratings for the combination of direct and flanking transmission paths.

When the calculated Flanking STC for a given path exceeds 90 dB, the value is limited to 90, to allow for
the inevitable effect of higher order flanking paths which make the higher calculated value notrepresentative of the true situation. Further enhancements to elements in these paths will give
negligible benefit. The consequence of this limit is that the Junction STC for the set of 3 paths at eachedge of the separating assembly cannot exceed 85 and the Total Flanking STC for all 4 edges cannot
exceed 79.
The numeric calculations present the arithmetic step-by-step in each worked example, using compact
notation consistent with spreadsheet expressions:For the calculation of the Direct STC, these expressions are easily recognized either as:o measured STC values without correction for a lining if the separating assembly is a wall;o measured STC values which may include corrections for added floor finishes if theseparating assembly is a floor with gypsum concrete surface.
For the calculation of the Flanking STC rating, these expressions are easily recognized as measured
Flanking STC values re-normalised according to Eq. 4.1.3, possibly with a Δ“TC o e tio for added
flooring if a floor with gypsum concrete surface is one of the flanking surfaces.
These STC or Flanking STC values are rounded to the nearest integer for consistency with thecorresponding measured values.

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Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings
For combining the sound power transmitted via specific paths, the calculation of Eq. 4.1.1 is presented
in several stages, first for the subset of paths at each junction, then for the combined effect of all four
flanking junctions, and finally for the combination of the direct path and all flanking paths. Note that in
the compact notation, a term for transmitted sound power fraction such as − . ∙STC becomes 10^7.4, if STCij = 74.
For each path or junction, the overall transmission result is converted into decibel form by calculating-10*log10 (transmitted sound power fraction) to facilitate comparison of each path or junction with the
Direct STC rating and the final ASTC rating.
The u e i g of the ta les p ese ti g the o ked e a ples e d i a alpha u e i su h as H o
V to i di ate Ho izo tal Case
ith oo s side-by-side) or Vertical Case 2 (with rooms one-abovethe-other), respectively.

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Page 75 of 102

Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

EXAMPLE 4.2-H1:


(SIMPLIFIED METHOD)

Illustration for this caseRooms side-by-side
Loadbearing junction with continuous joists and subfloor

Loadbearing separating wall assembly with: Wall CFS-S152-W33 (see Table 2.2.1) with short code
2G16_SS152(406)_GFB152_RC13(406)_G16
Junction 1: Separating wall / floor with:
 Junction code CFS-WF-LBc-13
 Floor name CFS-J254-F01 (see Table 2.3.1) with short code
GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
 CFS floor joists1 perpendicular to the loadbearing wall andcontinuous across the junction, with fire blocking at the junction.
 Gypsum concrete floor deck continuous across the junction.
Junction 2 or 4: Separating wall / abutting side wall with:
 Junction code CFS-WW-LB152-01
 Non-loadbearing flanking walls with short code
2G16_SS92(406)_GFB152_RC13(406)_G16, framing formed fromsteel 0.54 mm thick Closest CFS studs1 of the non-loadbearing walls are spaced 10 mmfrom framing of loadbearing wall.
 If gypsum board2 on loadbearing wall is directly attached toframing, gypsum board on adjacent non-loadbearing wall is
supported on resilient channels4, and vice versa.

Cross junction LBc of loadbearing
CFS-framed separating wall with
CFS-framed floor/ceiling assembly(Side view of Junctions 1 and 3)

Junction 3: Separating wall / ceiling with:
 Junction code CFS-WC-LBc-13(More complete descriptions of these assemblies and junctions withlarger drawings are given in Section 3.2.)
Acoustical Parameters:
Separating partition area ( m2 ) =Floor/separating wall junction length ( m ) =Wall/separating wall junction length ( m ) =In Scenario
12.5
5.0
2.5

Junction of separating wall withflanking side wall, both CFS-framed(Plan view of Junctions 2 and 4)

In Laboratory
12.5
5.0
2.5

Normalization for Junctions 1 and 3:
10*log(S_situ/S_lab) + 10*log(l_lab/l_situ) =0.00
RR-337, Eq. 4.1.3
RR-337 Flanking TL data normalized to Std. Scenario
Normalization for Junctions 2 and 4:
10*log(S_situ/S_lab) + 10*log(l_lab/l_situ) =0.00
RR-337, Eq. 4.1.3
RR-337 Flanking TL data normalized to Std. Scenario(See footnotes at end of document)

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Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

ISO Symbol
Separating Partition (Loadbearing CFS-Framed Wall)Laboratory STC for Dd
R_s,w
Direct STC in situ
R_Dd,w

STC, D_STC

Reference
RR-337, Wall CFS-S152-W33
RR-337, Eq. 4.1.2 (not a floor, so no ΔSTC correction)

ASTC

54
54

Junction 1 (Wall/Floor Junction LBc (loadbearing continuous) with CFS-Framed Floor)
For Flanking Path Ff_1:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-WF-LBc-13
50
Δ“TC ha ge Li i g o F
ΔR_F,
No flooring0
Δ“TC ha ge Li i g o f
ΔR_f,
No flooring0
Flanking STC for path Ff_1
R_Ff,w
RR-337, Eq. 4.1.3 and Eq. 4.1.5
50 + MAX(0,0)) + MIN(0,0)/2 + 0 =For Flanking Path Fd_1:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-WF-LBc-13
53
Δ“TC ha ge Li i g o F
ΔR_F,
No flooring0
Flanking STC for path Fd_1
R_ Fd,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
53 + 0 + 0 =For Flanking Path Df_1:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-WF-LBc-13
55
Δ“TC ha ge Li i g o f
ΔR_f,
No flooring0
Flanking STC for path Df_1
R_ Df,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
55 + 0 + 0 =Junction 1: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-5 + 10^- 5.3 + 10^- 5.5 ) =Junction 2 (Loadbearing CFS-Framed Separating Wall / Non-loadbearing CFS-Framed Flanking Walls)
For Flanking Path Ff_2:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-WW-LB152-01
82
Flanking STC for path Ff_2
R_Ff,w
RR-337, Eq. 4.1.3
82 + 0 =For Flanking Path Fd_2:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-WW-LB152-01
76
Flanking STC for path Fd_2
R_ Fd,w
RR-337, Eq. 4.1.3
76 + 0 =For Flanking Path Df_2:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-WW-LB152-01
82
Flanking STC for path Df_2
R_ Df,w
RR-337, Eq. 4.1.3
82 + 0 =Junction 2: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-8.2 + 10^- 7.6 + 10^- 8.2 ) =Junction 3 (Wall/Ceiling Junction LBc (loadbearing continuous) with CFS-Framed Floor/Ceiling)
For Flanking Path Ff_3:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-WC-LBc-13
65
Flanking STC for path Ff_3
R_Ff,w
RR-337, Eq. 4.1.3
65 + 0 =For Flanking Path Fd_3:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-WC-LBc-13
73
Flanking STC for path Fd_3
R_ Fd,w
RR-337, Eq. 4.1.3
73 + 0 =For Flanking Path Df_3:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-WC-LBc-13
69
Flanking STC for path Df_3
R_ Df,w
RR-337, Eq. 4.1.3
69 + 0 =Junction 3: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-6.5 + 10^- 7.3 + 10^- 6.9 ) =

50

53

55
47

82

76

82
74

65

73

69
63

Junction 4 (Loadbearing CFS-Framed Separating Wall / Non-loadbearing CFS-Framed Flanking Walls)
All values the same as for Junction_2
Flanking STC for path Ff_4
R_Ff,w
Same as for Ff_2
Flanking STC for path Fd_4
R_ Fd,w
Same as for Fd_2
Flanking STC for path Df_4
R_ Df,w
Same as for Df_2
Junction 4: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-8.2 + 10^- 7.6 + 10^- 8.2 ) =Total Flanking STC (4 Junctions)
Subset of Eq. 4.1.1
Combining 12 Flanking STC values

82
76
82

ASTC due to Direct plus Total Flanking

46

Equation 4.1.1

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Combining Direct STC with 12 Flanking STC values

74
47

Page 77 of 102

Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

EXAMPLE 4.2-H2:


(SIMPLIFIED METHOD)

Illustration for this caseRooms side-by-side
Loadbearing junction with discontinuous joists and subfloor

Loadbearing separating wall assembly with: Wall CFS-S152-W33 (see Table 2.2.1) with short code
2G16_SS152(406)_GFB152_RC13(406)_2G16
Junction 1: Separating wall / floor with:
 Junction code CFS-WF-LBd-21
 Floor name CFS-J254-F01 (see Table 2.3.1) with short code
GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
 CFS floor joists1 perpendicular to the loadbearing wall but notcontinuous across the junction.
 Gypsum concrete floor deck discontinuous at the junction.
Junction 2 or 4: Separating wall / abutting side wall with:
 Junction code CFS-WW-LB152-01
 Non-loadbearing flanking walls with short code
2G16_SS92(406)_GFB152_RC13(406)_2G16, framing formed fromsteel 0.54 mm thick Closest CFS studs1 of the non-loadbearing walls spaced 10 mmfrom framing of loadbearing wall.
 If gypsum board2 on loadbearing wall is directly attached toframing, gypsum board on adjacent non-loadbearing wall is
supported on resilient channels4, and vice versa.

Cross junction LBd of loadbearing
CFS-framed separating wall with CFSframed floor/ceiling assembly(Side view of Junctions 1 and 3)

Junction 3: Separating wall / ceiling with:
 Junction code CFS-WC-LBd-21(More complete descriptions of these assemblies and junctions withlarger drawings are given in Section 3.2.)
Acoustical Parameters:
Separating partition area ( m2 ) =Floor/separating wall junction length ( m ) =Wall/separating wall junction length ( m ) =In Scenario
12.5
5.0
2.5

Junction of separating wall withflanking side wall, both CFS-framed(Plan view of Junctions 2 and 4)

In Laboratory
12.5
5.0
2.5

Normalization for Junctions 1 and 3:
10*log(S_situ/S_lab) + 10*log(l_lab/l_situ) =0.00
RR-337, Eq. 4.1.3
RR-337 Flanking TL data normalized to Std. Scenario
Normalization for Junctions 2 and 4:
10*log(S_situ/S_lab) + 10*log(l_lab/l_situ) =0.00
RR-337, Eq. 4.1.3
RR-337 Flanking TL data normalized to Std. Scenario(See footnotes at end of document)

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Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

ISO Symbol
Separating Partition (Loadbearing CFS-Framed Wall)Laboratory STC for Dd
R_s,w
Direct STC in situ
R_Dd,w

STC, D_STC

Reference
RR-337, Wall CFS-S152-W33
RR-337, Eq. 4.1.2 (not a floor, so no ΔSTC correction)

ASTC

58
58

Junction 1 (Wall/Floor Junction LBd (loadbearing discontinuous) with CFS-Framed Floor)
For Flanking Path Ff_1:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-WF-LBd-21
65
Δ“TC ha ge Li i g o F
ΔR_F,
No flooring0
Δ“TC ha ge Li i g o f
ΔR_f,
No flooring0
Flanking STC for path Ff_1
R_Ff,w
RR-337, Eq. 4.1.3 and Eq. 4.1.5
65 + MAX(0,0)) + MIN(0,0)/2 + 0 =For Flanking Path Fd_1:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-WF-LBd-21
62
Δ“TC ha ge Li i g o F
ΔR_F,
No flooring0
Flanking STC for path Fd_1
R_ Fd,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
62 + 0 + 0 =For Flanking Path Df_1:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-WF-LBd-21
67
Δ“TC ha ge Li i g o f
ΔR_f,
No flooring0
Flanking STC for path Df_1
R_ Df,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
67 + 0 + 0 =Junction 1: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-6.5 + 10^- 6.2 + 10^- 6.7 ) =Junction 2 (Loadbearing CFS-Framed Separating Wall / Non-loadbearing CFS-Framed Flanking Walls)
For Flanking Path Ff_2:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-WW-LB152-01
82
Flanking STC for path Ff_2
R_Ff,w
RR-337, Eq. 4.1.3
82 + 0 =For Flanking Path Fd_2:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-WW-LB152-01
76
Flanking STC for path Fd_2
R_ Fd,w
RR-337, Eq. 4.1.3
76 + 0 =For Flanking Path Df_2:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-WW-LB152-01
82
Flanking STC for path Df_2
R_ Df,w
RR-337, Eq. 4.1.3
82 + 0 =Junction 2: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-8.2 + 10^- 7.6 + 10^- 8.2 ) =Junction 3 (Wall/Ceiling Junction LBd (loadbearing discontinuous) with CFS-Framed Floor/Ceiling)
For Flanking Path Ff_3:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-WC-LBd-21
75
Flanking STC for path Ff_3
R_Ff,w
RR-337, Eq. 4.1.3
75 + 0 =For Flanking Path Fd_3:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-WC-LBd-21
64
Flanking STC for path Fd_3
R_ Fd,w
RR-337, Eq. 4.1.3
For Flanking Path Df_3:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-WC-LBd-21
70
Flanking STC for path Df_3
R_ Df,w
RR-337, Eq. 4.1.3
70 + 0 =Junction 3: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-7.5 + 10^- 6.4 + 10^- 7 ) =

65

62

67
59

82

76

82
74

75

64

70
63

Junction 4 (Loadbearing CFS-Framed Separating Wall / Non-loadbearing CFS-Framed Flanking Walls)
All values the same as for Junction_2
Flanking STC for path Ff_4
R_Ff,w
Same as for Ff_2
Flanking STC for path Fd_4
R_ Fd,w
Same as for Fd_2
Flanking STC for path Df_4
R_ Df,w
Same as for Df_2
Junction 4: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-8.2 + 10^- 7.6 + 10^- 8.2 ) =Total Flanking STC (4 Junctions)
Subset of Eq. 4.1.1
Combining 12 Flanking STC values

82
76
82

ASTC due to Direct plus Total Flanking

55

Equation 4.1.1

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Combining Direct STC with 12 Flanking STC values

74
58

Page 79 of 102

Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

EXAMPLE 4.2-H3:


(SIMPLIFIED METHOD)

Illustration for this caseRooms side-by-side
Non-loadbearing junction with continuous subfloor

Non-loadbearing separating wall assembly with:
 Non-loadbearing separating walls with short code
2G16_SS92(406)_GFB92_RC13(406)_2G16, framing formed fromsteel 0.54 mm thick
Junction 1: Separating wall / floor with:
 Junction code CFS-WF-NLBc-31
 Floor name CFS-J254-F01 (see Table 2.3.1) with short code
GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
 CFS floor joists1 parallel to the non-loadbearing wall
 Gypsum concrete floor deck continuous across the junction.
Junction 2 or 4: Separating wall / abutting side wall with:
 Junction code CFS-WW-NLB92-01
 Loadbearing flanking walls Wall CFS-S152-W33 (see Table 2.2.1)
with short code 2G16_SS152(406)_GFB152_RC13(406)_2G16
 Closest CFS studs1 of the non-loadbearing walls spaced 10 mmfrom framing of loadbearing wall.
 If gypsum board2 on loadbearing wall is directly attached toframing, gypsum board on adjacent non-loadbearing wall is
supported on resilient channels4, and vice versa.

Cross junction NLBc of nonloadbearing CFS-framed separatingwall assembly with CFS-framed
floor/ceiling assembly(Side view of Junctions 1 and 3)

Junction 3: Separating wall / ceiling with:
 Junction code CFS-WC-NLBc-31(More complete descriptions of these assemblies and junctions withlarger drawings are given in Section 3.2.)
Acoustical Parameters:
Separating partition area ( m2 ) =Floor/separating wall junction length ( m ) =Wall/separating wall junction length ( m ) =In Scenario
12.5
5.0
2.5

In Laboratory
12.5
5.0
2.5

Junction of separating wall withflanking side wall, both CFS-framed(Plan view of Junctions 2 and 4)

Normalization for Junctions 1 and 3:
10*log(S_situ/S_lab) + 10*log(l_lab/l_situ) =0.00
RR-337, Eq. 4.1.3
RR-337 Flanking TL data normalized to Std. Scenario
Normalization for Junctions 2 and 4:
10*log(S_situ/S_lab) + 10*log(l_lab/l_situ) =0.00
RR-337, Eq. 4.1.3
RR-337 Flanking TL data normalized to Std. Scenario(See footnotes at end of document)

Page 80 of 102

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Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

ISO Symbol

STC, D_STC

Reference

Separating Partition (Non-Loadbearing CFS-Framed Wall)Laboratory STC for Dd
R_s,w
RR-337, NLB wall 2G16_SS92(406)_GFB92_RC13(406RR-337, Eq. 4.1.2 (not a floor, so no ΔSTC correction)
Direct STC in situ
R_Dd,w

ASTC

57
57

Junction 1 (Wall/Floor Junction NLBc (Non-loadbearing continuous) with CFS-Framed Floor)
For Flanking Path Ff_1:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-WF-NLBc-31
40
Δ“TC ha ge Li i g o F
ΔR_F,
No flooring0
Δ“TC ha ge Li i g o f
ΔR_f,
No flooring0
Flanking STC for path Ff_1
R_Ff,w
RR-337, Eq. 4.1.3 and Eq. 4.1.5
40 + MAX(0,0)) + MIN(0,0)/2 + 0 =For Flanking Path Fd_1:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-WF-NLBc-31
49
Δ“TC ha ge Li i g o F
ΔR_F,
No flooring0
Flanking STC for path Fd_1
R_ Fd,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
49 + 0 + 0 =For Flanking Path Df_1:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-WF-NLBc-31
50
Δ“TC ha ge Li i g o f
ΔR_f,
No flooring0
Flanking STC for path Df_1
R_ Df,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
50 + 0 + 0 =Junction 1: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-4 + 10^- 4.9 + 10^- 5 ) =Junction 2 (Non-Loadbearing CFS-Framed Separating Wall / Loadbearing CFS-Framed Flanking Walls)
For Flanking Path Ff_2:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-WW-NLB92-01
84
Flanking STC for path Ff_2
R_Ff,w
RR-337, Eq. 4.1.3
84 + 0 =For Flanking Path Fd_2:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-WW-NLB92-01
82
Flanking STC for path Fd_2
R_ Fd,w
RR-337, Eq. 4.1.3
82 + 0 =For Flanking Path Df_2:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-WW-NLB92-01
81
Flanking STC for path Df_2
R_ Df,w
RR-337, Eq. 4.1.3
81 + 0 =Junction 2: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-8.4 + 10^- 8.2 + 10^- 8.1 ) =Junction 3 (Wall/Ceiling Junction NLBc (non-loadbearing continuous) with CFS-Framed Floor/Ceiling)
For Flanking Path Ff_3:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-WC-NLBc-31
67
Flanking STC for path Ff_3
R_Ff,w
RR-337, Eq. 4.1.3
67 + 0 =For Flanking Path Fd_3:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-WC-NLBc-31
65
Flanking STC for path Fd_3
R_ Fd,w
RR-337, Eq. 4.1.3
65 + 0 =For Flanking Path Df_3:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-WC-NLBc-31
71
Flanking STC for path Df_3
R_ Df,w
RR-337, Eq. 4.1.3
71 + 0 =Junction 3: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-6.7 + 10^- 6.5 + 10^- 7.1 ) =

40

49

50
39

84

82

81
77

67

65

71
62

Junction 4 (Non-Loadbearing CFS-Framed Separating Wall / loadbearing CFS-Framed Flanking Walls)
All values the same as for Junction_2
Flanking STC for path Ff_4
R_Ff,w
Same as for Ff_2
Flanking STC for path Fd_4
R_ Fd,w
Same as for Fd_2
Flanking STC for path Df_4
R_ Df,w
Same as for Df_2
Junction 4: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-8.4 + 10^- 8.2 + 10^- 8.1 ) =Total Flanking STC (4 Junctions)
Subset of Eq. 4.1.1
Combining 12 Flanking STC values

84
82
81

ASTC due to Direct plus Total Flanking

39

Equation 4.1.1

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Combining Direct STC with 12 Flanking STC values

77
39

Page 81 of 102

Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

EXAMPLE 4.2-H4:


(SIMPLIFIED METHOD)

Illustration for this caseRooms side-by-side
Non-loadbearing junction with discontinuous subfloor

Non-loadbearing separating wall assembly with:
 Non-loadbearing separating wall with short code
2G16_SS92(406)_GFB92_RC13(406)_2G16, framing formed fromsteel 0.54 mm thick
Junction 1: Separating wall / floor with:
 Junction code CFS-WF-NLBd-41
 Floor name CFS-J254-F01 (see Table 2.3.1) with short code
GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
 CFS floor joists1 parallel to the non-loadbearing wall
 Gypsum concrete floor deck discontinuous at the junction.
Junction 2 or 4: Separating wall / abutting side wall with:
 Junction code CFS-WW-NLB92-01
 Loadbearing flanking walls Wall CFS-S152-W33 (see Table 2.2.1)
with short code 2G16_SS152(406)_GFB152_RC13(406)_2G16
 Closest CFS studs1 of the non-loadbearing walls spaced 10 mmfrom framing of loadbearing wall.
 If gypsum board2 on loadbearing wall is directly attached toframing, gypsum board on adjacent non-loadbearing wall is
supported on resilient channels4, and vice versa.

Cross junction NLBd of the nonloadbearing CFS-framed separatingwall with CFS-framed floor/ceilingassembly(Side view of Junctions 1 and 3)

Junction 3: Separating wall / ceiling with:
 Junction code CFS-WC-NLBd-41(More complete descriptions of these assemblies and junctions withlarger drawings are given in Section 3.2.)
Acoustical Parameters:
Separating partition area ( m2 ) =Floor/separating wall junction length ( m ) =Wall/separating wall junction length ( m ) =In Scenario
12.5
5.0
2.5

In Laboratory
12.5
5.0
2.5

Junction of separating wall withflanking side wall, both CFS-framed(Plan view of Junctions 2 and 4)

Normalization for Junctions 1 and 3:
10*log(S_situ/S_lab) + 10*log(l_lab/l_situ) =0.00
RR-337, Eq. 4.1.3
RR-337 Flanking TL data normalized to Std. Scenario
Normalization for Junctions 2 and 4:
10*log(S_situ/S_lab) + 10*log(l_lab/l_situ) =0.00
RR-337, Eq. 4.1.3
RR-337 Flanking TL data normalized to Std. Scenario(See footnotes at end of document)

Page 82 of 102

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

ISO Symbol

STC, D_STC

Reference

Separating Partition (Non-Loadbearing CFS-Framed Wall)Laboratory STC for Dd
R_s,w
RR-337, NLB wall 2G16_SS92(406)_GFB92_RC13(406)_
RR-337, Eq. 4.1.2 (not a floor, so no ΔSTC correction)
Direct STC in situ
R_Dd,w

ASTC

57
57

Junction 1 (Wall/Floor Junction NLBd (Non-loadbearing discontinuous) with CFS-Framed Floor)
For Flanking Path Ff_1:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-WF-NLBd-41
60
Δ“TC ha ge Li i g o F
ΔR_F,
No flooring0
Δ“TC ha ge Li i g o f
ΔR_f,
No flooring0
Flanking STC for path Ff_1
R_Ff,w
RR-337, Eq. 4.1.3 and Eq. 4.1.5
60 + MAX(0,0)) + MIN(0,0)/2 + 0 =For Flanking Path Fd_1:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-WF-NLBd-41
63
Δ“TC ha ge Li i g o F
ΔR_F,
No flooring0
Flanking STC for path Fd_1
R_ Fd,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
63 + 0 + 0 =For Flanking Path Df_1:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-WF-NLBd-41
67
Δ“TC ha ge Li i g o f
ΔR_f,
No flooring0
Flanking STC for path Df_1
R_ Df,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
67 + 0 + 0 =Junction 1: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-6 + 10^- 6.3 + 10^- 6.7 ) =Junction 2 (Non-Loadbearing CFS-Framed Separating Wall / loadbearing CFS-Framed Flanking Walls)
For Flanking Path Ff_2:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-WW-NLB92-01
84
Flanking STC for path Ff_2
R_Ff,w
RR-337, Eq. 4.1.3
84 + 0 =For Flanking Path Fd_2:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-WW-NLB92-01
82
Flanking STC for path Fd_2
R_ Fd,w
RR-337, Eq. 4.1.3
82 + 0 =For Flanking Path Df_2:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-WW-NLB92-01
81
Flanking STC for path Df_2
R_ Df,w
RR-337, Eq. 4.1.3
81 + 0 =Junction 2: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-8.4 + 10^- 8.2 + 10^- 8.1 ) =Junction 3 (Wall/Ceiling Junction NLBd (non-loadbearing discontinuous) with CFS-Framed Floor/Ceiling)
For Flanking Path Ff_3:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-WC-NLBd-41
77
Flanking STC for path Ff_3
R_Ff,w
RR-337, Eq. 4.1.3
77 + 0 =For Flanking Path Fd_3:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-WC-NLBd-41
70
Flanking STC for path Fd_3
R_ Fd,w
RR-337, Eq. 4.1.3
70 + 0 =For Flanking Path Df_3:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-WC-NLBd-41
69
Flanking STC for path Df_3
R_ Df,w
RR-337, Eq. 4.1.3
69 + 0 =Junction 3: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-7.7 + 10^- 7 + 10^- 6.9 ) =

60

63

67
58

84

82

81
77

77

70

69
66

Junction 4 (Non-Loadbearing CFS-Framed Separating Wall / loadbearing CFS-Framed Flanking Walls)
All values the same as for Junction_2
Flanking STC for path Ff_4
R_Ff,w
Same as for Ff_2
Flanking STC for path Fd_4
R_ Fd,w
Same as for Fd_2
Flanking STC for path Df_4
R_ Df,w
Same as for Df_2
Junction 4: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-8.4 + 10^- 8.2 + 10^- 8.1 ) =Total Flanking STC (4 Junctions)
Subset of Eq. 4.1.1
Combining 12 Flanking STC values

84
82
81

ASTC due to Direct plus Total Flanking

54

Equation 4.1.1

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Combining Direct STC with 12 Flanking STC values

77
57

Page 83 of 102

Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

EXAMPLE 4.2-H5:



(SIMPLIFIED METHOD)

Illustration for this caseRooms side-by-side
Loadbearing junction with continuous joists and subfloor
Same as EXAMPLE 4.2-H1 with added finish flooring

Loadbearing separating wall assembly with: Wall CFS-S152-W33 (see Table 2.2.1) with short code
2G16_SS152(406)_GFB152_RC13(406)_G16
Junction 1: Separating wall / floor with:
 Junction code CFS-WF-LBc-13
 Floor name CFS-J254-F01 (see Table 2.3.1) with short code
GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
 CFS floor joists1 perpendicular to the loadbearing wall andcontinuous across the junction with fire blocking at the junction.
 Gypsum concrete floor deck continuous across the junction.
 Finish flooring LAM10_FOAM3 installed over the subfloor.

Cross junction LBc of loadbearing
CFS-framed separating wall with CFSframed floor/ceiling assembly(Side view of Junctions 1 and 3)

Junction 2 or 4: Separating wall / abutting side wall with:
 Junction code CFS-WW-LB152-01
 Non-loadbearing flanking walls with short code
2G16_SS92(406)_GFB152_RC13(406)_G16, framing formed fromsteel 0.54 mm thick Closest CFS studs1 of the non-loadbearing walls spaced 10 mmfrom framing of loadbearing wall.
 If gypsum board2 on loadbearing wall is directly attached toframing, gypsum board on adjacent non-loadbearing wall is
supported on resilient channels4, and vice versa.
Junction 3: Separating wall / ceiling with:
 Junction code CFS-WC-LBc-13(More complete descriptions of these assemblies and junctions withlarger drawings are given in Section 3.2.)

Junction of separating wall withflanking side wall, both CFS-framed(Plan view of Junctions 2 and 4)

Acoustical Parameters:
Separating partition area ( m2 ) =Floor/separating wall junction length ( m ) =Wall/separating wall junction length ( m ) =In Scenario
12.5
5.0
2.5

In Laboratory
12.5
5.0
2.5

Normalization for Junctions 1 and 3:
10*log(S_situ/S_lab) + 10*log(l_lab/l_situ) =0.00
RR-337, Eq. 4.1.3
RR-337 Flanking TL data normalized to Std. Scenario
Normalization for Junctions 2 and 4:
10*log(S_situ/S_lab) + 10*log(l_lab/l_situ) =0.00
RR-337, Eq. 4.1.3
RR-337 Flanking TL data normalized to Std. Scenario(See footnotes at end of document)

Page 84 of 102

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

ISO Symbol
Separating Partition (Loadbearing CFS-Framed Wall)Laboratory STC for Dd
R_s,w
Direct STC in situ
R_Dd,w

STC, D_STC

Reference
RR-337, wall CFS-S152-W33
RR-337, Eq. 4.1.2 (not a floor, so no ΔSTC correction)

ASTC

54
54

Junction 1 (Wall/Floor Junction LBc (loadbearing continuous) with CFS-Framed Floor)
For Flanking Path Ff_1:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-WF-LBc-13
50
ΔTL-CF“-F , floo i g LAM10_FOAM3 on GCON32
2
Δ“TC ha ge Li i g o F
ΔR_F,
Δ“TC ha ge Li i g o f
ΔR_f,
ΔTL-CF“-F , floo i g LAM10_FOAM3 on GCON32
2
Flanking STC for path Ff_1
R_Ff,w
RR-337, Eq. 4.1.3 and Eq. 4.1.5
50 + MAX(2,2)) + MIN(2,2)/2 + 0 =For Flanking Path Fd_1:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-WF-LBc-13
53
ΔTL-CF“-F , floo i g LAM10_FOAM3 on GCON32
2
Δ“TC ha ge Li i g o F
ΔR_F,
Flanking STC for path Fd_1
R_ Fd,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
53 + 2 + 0 =For Flanking Path Df_1:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-WF-LBc-13
55
ΔTL-CF“-F , floo i g LAM10_FOAM3 on GCON32
2
Δ“TC ha ge Li i g o f
ΔR_f,
Flanking STC for path Df_1
R_ Df,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
55 + 2 + 0 =Junction 1: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-5.3 + 10^- 5.5 + 10^- 5.7 ) =Junction 2 (Loadbearing CFS-Framed Separating Wall / Non-loadbearing CFS-Framed Flanking Walls)
For Flanking Path Ff_2:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-WW-LB152-01
82
Flanking STC for path Ff_2
R_Ff,w
RR-337, Eq. 4.1.3
82 + 0 =For Flanking Path Fd_2:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-WW-LB152-01
76
Flanking STC for path Fd_2
R_ Fd,w
RR-337, Eq. 4.1.3
76 + 0 =For Flanking Path Df_2:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-WW-LB152-01
82
Flanking STC for path Df_2
R_ Df,w
RR-337, Eq. 4.1.3
82 + 0 =Junction 2: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-8.2 + 10^- 7.6 + 10^- 8.2 ) =Junction 3 (Wall/Ceiling Junction LBc (loadbearing continuous) with CFS-Framed Floor/Ceiling)
For Flanking Path Ff_3:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-WC-LBc-13
65
Flanking STC for path Ff_3
R_Ff,w
RR-337, Eq. 4.1.3
65 + 0 =For Flanking Path Fd_3:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-WC-LBc-13
73
Flanking STC for path Fd_3
R_ Fd,w
RR-337, Eq. 4.1.3
73 + 0 =For Flanking Path Df_3:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-WC-LBc-13
69
Flanking STC for path Df_3
R_ Df,w
RR-337, Eq. 4.1.3
69 + 0 =Junction 3: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-6.5 + 10^- 7.3 + 10^- 6.9 ) =

53

55

57
50

82

76

82
74

65

73

69
63

Junction 4 (Loadbearing CFS-Framed Separating Wall / Non-loadbearing CFS-Framed Flanking Walls)
All values the same as for Junction_2
Flanking STC for path Ff_4
R_Ff,w
Same as for Ff_2
Flanking STC for path Fd_4
R_ Fd,w
Same as for Fd_2
Flanking STC for path Df_4
R_ Df,w
Same as for Df_2
Junction 4: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-8.2 + 10^- 7.6 + 10^- 8.2 ) =Total Flanking STC (4 Junctions)
Subset of Eq. 4.1.1
Combining 12 Flanking STC values

82
76
82

ASTC due to Direct plus Total Flanking

48

Equation 4.1.1

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Combining Direct STC with 12 Flanking STC values

74
50

Page 85 of 102

Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

EXAMPLE 4.2-V1:
(SIMPLIFIED METHOD)

Illustration for this caseRooms one above the other

Loadbearing separating floor assembly with:
 Separating floor/ceiling CFS-J254-F01 (see Table 2.3.1) with shortcode GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
Junction 1 or 3: Separating floor / loadbearing walls with:
 Junction code CFS-FW-LBc-11
 Loadbearing flanking walls CFS-S152-W33 (see Table 2.2.1) withshort code 2G16_SS152(406)_GFB152_RC13(406)_2G16
 Gypsum board2 supported on resilient channels4 (Junction 1) or
attached directly to wall framing (Junction 3).
 CFS floor joists1 perpendicular to the loadbearing wall andcontinuous across the junction and gypsum concrete floor deck
continuous across the junction.
Junction 2 or 4: Separating floor / non-loadbearing walls with:
 Junction code CFS-FW-NLBd-41
 Non-loadbearing flanking walls with short code
2G16_SS92(406)_GFB92_RC13(406)_2G16 with CFS studs1 formed
from steel 0.54 mm thick.
 Gypsum board2 attached directly to wall framing CFS floor joists1 parallel to the non-loadbearing wall.
 Gypsum concrete floor deck discontinuous across the junction.

Cross junction CFS-FW-LBc-11 ofloadbearing CFS-framed separatingwall with CFS-framed floor/ceiling(Side view of Junctions 1 and 3)(More complete descriptions of these assemblies and junctions withlarger drawings are given in Section 3.2.)
Acoustical Parameters:
Separating partition area ( m2 ) =Floor/LB flanking wall junction length ( m ) =Floor/NLB flanking wall junction length ( m ) =In Scenario
20.0
5.0
4.0

In Laboratory
20.0
5.0
5.0

Normalization for Junctions 1 and 3:
10*log(S_situ/S_lab) + 10*log(l_lab/l_situ) =0.00
RR-337, Eq. 4.1.3
RR-337 Flanking TL data normalized to Std. Scenario
Normalization for Junctions 2 and 4:
10*log(S_situ/S_lab) + 10*log(l_lab/l_situ) =0.97
RR-337, Eq. 4.1.3
RR-337 Flanking TL data normalized to Std. Scenario

Cross junction CFS-FW-NLBd-41 of
non-loadbearing CFS-framed wallwith CFS-framed floor/ceiling(Side view of Junctions 2 and 4)(See footnotes at end of document)

Page 86 of 102

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

ISO Symbol
Separating Partition (CFS-Framed Floor)
Laboratory STC for Dd
Δ“TC change by Lining on D
Direct STC in situ

R_s,w
ΔR_D,w
R_Dd,w

STC, D_STC

Reference
RR-337, floor CFS-J254-F01
No finish flooring
RR-337, Eq. 4.1.2

57
057 + 0 =Junction 1 (Floor/Wall Junction LBc of CFS-Framed Floor with Loadbearing Wall)
For Flanking Path Ff_1:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-FW-LBc-11r, wall gypsum board on RC
67
Flanking STC for path Ff_1
R_Ff,w
RR-337, Eq. 4.1.3
67 + 0 =For Flanking Path Fd_1:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-FW-LBc-11r, wall gypsum board on RC
71
Flanking STC for path Fd_1
R_ Fd,w
RR-337, Eq. 4.1.3
71 + 0 =For Flanking Path Df_1:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-FW-LBc-11r, wall gypsum board on RC
72
Δ“TC ha ge Li i g o D
ΔR_D,
No finish flooring0
Flanking STC for path Df_1
R_ Df,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
72 + 0 + 0 =Junction 1: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-6.7 + 10^- 7.1 + 10^- 7.2 ) =Junction 2 (Floor/Wall Junction NLBd of CFS-Framed Floor with Non-loadbearing Wall)
For Flanking Path Ff_2:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-FW-NLBd-41d, wall gypsum board direct
72
Flanking STC for path Ff_2
R_Ff,w
RR-337, Eq. 4.1.3
72 + 1 =For Flanking Path Fd_2:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-FW-NLBd-41d, wall gypsum board direct
76
Flanking STC for path Fd_2
R_ Fd,w
RR-337, Eq. 4.1.3
76 + 1 =For Flanking Path Df_2:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-FW-NLBd-41d, wall gypsum board direct
74
Δ“TC ha ge Li i g o D
ΔR_D,
No finish flooring0
Flanking STC for path Df_2
R_ Df,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
74 + 0 + 1 =Junction 2: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-7.3 + 10^- 7.7 + 10^- 7.5 ) =Junction 3 (Floor/Wall Junction LBc of CFS-Framed Floor with Loadbearing Wall)
For Flanking Path Ff_3:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-FW-LBc-11d, wall gypsum board direct
67
Flanking STC for path Ff_3
R_Ff,w
RR-337, Eq. 4.1.3
67 + 0 =For Flanking Path Fd_3:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-FW-LBc-11d, wall gypsum board direct
69
Flanking STC for path Fd_3
R_ Fd,w
RR-337, Eq. 4.1.3
69 + 0 =For Flanking Path Df_3:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-FW-LBc-11d, wall gypsum board direct
65
Δ“TC ha ge Li i g o D
ΔR_D,
No finish flooring0
Flanking STC for path Df_3
R_ Df,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
65 + 0 + 0 =Junction 3: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-6.7 + 10^- 6.9 + 10^- 6.5 ) =Junction 4 (Floor/Wall Junction NLBd of CFS-Framed Floor with Non-loadbearing Wall)All values the same as for Junction_2
Flanking STC for path Ff_4
R_Ff,w
Same as for Ff_2
Flanking STC for path Fd_4
R_ Fd,w
Same as for Fd_2
Flanking STC for path Df_4
R_ Df,w
Same as for Df_2
Junction 4: Flanking STC for all paths
Subset of Eq. 4.1.1
Total Flanking STC (4 Junctions)
Subset of Eq. 4.1.1
ASTC due to Direct plus Total Flanking

Equation 4.1.1

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

ASTC

57

67

71

72
65

73

77

75
70

67

69

65
62

73
77
75
70
59

- 10*LOG10(10^-7.3 + 10^- 7.7 + 10^- 7.5 ) =Combining 12 Flanking STC values

Combining Direct STC with 12 Flanking STC values

55

Page 87 of 102

Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

EXAMPLE 4.2-V2:



(SIMPLIFIED METHOD)

Illustration for this caseRooms one above the other
Same as EXAMPLE 4.2-V1 with added finish flooring

Loadbearing separating floor assembly with:
 Separating floor/ceiling CFS-J254-F01 (see Table 2.3.1) with shortcode GCON32_CORSTE14_SJ254(406)_GFB92_RC13(305)_G16
Junction 1 or 3: Junction of separating floor / loadbearing walls:
 Junction code CFS-FW-LBc-11
 Loadbearing flanking walls CFS-S152-W33 (see Table 2.2.1) withshort code 2G16_SS152(406)_GFB152_RC13(406)_2G16
 Gypsum board2 supported on resilient channels4 (Junction 1) or
attached directly to wall framing (Junction 3).
 CFS floor joists1 perpendicular to the loadbearing wall andcontinuous across the junction and gypsum concrete floor deck
continuous across the junction.
 Finish flooring LAM10_FOAM3 installed over the subfloor.

Cross junction CFS-FW-LBc-11 ofloadbearing CFS-framed separatingwall with CFS-framed floor/ceiling(Side view of Junctions 1 and 3)

Junction 2 or 4: Junction of separating floor / non-loadbearing walls:
 Junction code CFS-FW-NLBd-41
 Non-loadbearing flanking walls with short code
2G16_SS92(406)_GFB92_RC13(406)_2G16 with CFS studs1 formed
from steel 0.54 mm thick.
 Gypsum board2 attached directly to wall framing CFS floor joists1 parallel to the non-loadbearing wall.
 Gypsum concrete floor deck discontinuous across the junction.
 Finish flooring LAM10_FOAM3 installed over the subfloor.
(More complete descriptions of these assemblies and junctions withlarger drawings are given in Section 3.2.)
Acoustical Parameters:
Separating partition area ( m2 ) =Floor/LB flanking wall junction length ( m ) =Floor/NLB flanking wall junction length ( m ) =In Scenario
20.0
5.0
4.0

In Laboratory
20.0
5.0
5.0

Cross junction CFS-FW-NLBd-41 of
non-loadbearing CFS-framed wallwith CFS-framed floor/ceiling(Side view of Junctions 2 and 4)

Normalization for Junctions 1 and 3:
10*log(S_situ/S_lab) + 10*log(l_lab/l_situ) =0.00
RR-337, Eq. 4.1.3
RR-337 Flanking TL data normalized to Std. Scenario
Normalization for Junctions 2 and 4:
10*log(S_situ/S_lab) + 10*log(l_lab/l_situ) =0.97
RR-337, Eq. 4.1.3
RR-337 Flanking TL data normalized to Std. Scenario(See footnotes at end of document)

Page 88 of 102

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

ISO Symbol
Separating Partition (CFS-Framed Floor)
Laboratory STC for Dd
Δ“TC change by Lining on D
Direct STC in situ

R_s,w
ΔR_D,w
R_Dd,w

STC, D_STC

Reference
RR-337, floor CFS-J254-F01
ΔTL-CF“-F , floo i g LAM10_FOAM3 on GCON32
RR-337, Eq. 4.1.2

57
2
57 + 2 =Junction 1 (Floor/Wall Junction LBc of CFS-Framed Floor with Loadbearing Wall)
For Flanking Path Ff_1:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-FW-LBc-11r, wall gypsum board on RC
67
Flanking STC for path Ff_1
R_Ff,w
RR-337, Eq. 4.1.3
67 + 0 =For Flanking Path Fd_1:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-FW-LBc-11r, wall gypsum board on RC
71
Flanking STC for path Fd_1
R_ Fd,w
RR-337, Eq. 4.1.3
71 + 0 =For Flanking Path Df_1:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-FW-LBc-11r, wall gypsum board on RC
72
ΔTL-CF“-F , floo i g LAM10_FOAM3 on GCON32
2
Δ“TC ha ge Li i g o D
ΔR_D,
Flanking STC for path Df_1
R_ Df,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
72 + 2 + 0 =Junction 1: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-6.7 + 10^- 7.1 + 10^- 7.4 ) =Junction 2 (Floor/Wall Junction NLBd of CFS-Framed Floor with Non-loadbearing Wall)
For Flanking Path Ff_2:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-FW-NLBd-41d, wall gypsum board direct
72
Flanking STC for path Ff_2
R_Ff,w
RR-337, Eq. 4.1.3
72 + 1 =For Flanking Path Fd_2:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-FW-NLBd-41d, wall gypsum board direct
76
Flanking STC for path Fd_2
R_ Fd,w
RR-337, Eq. 4.1.3
76 + 1 =For Flanking Path Df_2:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-FW-NLBd-41d, wall gypsum board direct
74
Δ“TC ha ge Li i g o D
ΔR_D,
ΔTL-CF“-F , floo i g LAM10_FOAM3 on GCON32
2
Flanking STC for path Df_2
R_ Df,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
74 + 2 + 1 =Junction 2: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-7.3 + 10^- 7.7 + 10^- 7.7 ) =Junction 3 (Floor/Wall Junction LBc of CFS-Framed Floor with Loadbearing Wall)
For Flanking Path Ff_3:
Laboratory Flanking STC
Measured Path Ff RR-337, CFS-FW-LBc-11d, wall gypsum board direct
67
Flanking STC for path Ff_3
R_Ff,w
RR-337, Eq. 4.1.3
67 + 0 =For Flanking Path Fd_3:
Laboratory Flanking STC
Measured Path Fd RR-337, CFS-FW-LBc-11d, wall gypsum board direct
69
Flanking STC for path Fd_3
R_ Fd,w
RR-337, Eq. 4.1.3
69 + 0 =For Flanking Path Df_3:
Laboratory Flanking STC
Measured Path Df RR-337, CFS-FW-LBc-11d, wall gypsum board direct
65
Δ“TC ha ge Li i g o D
ΔR_D,
ΔTL-CF“-F , floo i g LAM10_FOAM3 on GCON32
2
Flanking STC for path Df_3
R_ Df,w
RR-337, Eq. 4.1.3 and Eq. 4.1.4
65 + 2 + 0 =Junction 3: Flanking STC for all paths
Subset of Eq. 4.1.1- 10*LOG10(10^-6.7 + 10^- 6.9 + 10^- 6.7 ) =Junction 4 (Floor/Wall Junction NLBd of CFS-Framed Floor with Non-loadbearing Wall)All values the same as for Junction_2
Flanking STC for path Ff_4
R_Ff,w
Same as for Ff_2
Flanking STC for path Fd_4
R_ Fd,w
Same as for Fd_2
Flanking STC for path Df_4
R_ Df,w
Same as for Df_2
Junction 4: Flanking STC for all paths
Subset of Eq. 4.1.1
Total Flanking STC (4 Junctions)
Subset of Eq. 4.1.1
ASTC due to Direct plus Total Flanking

Equation 4.1.1

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

ASTC

59

67

71

74
65

73

77

77
70

67

69

67
63

73
77
77
70
60

- 10*LOG10(10^-7.3 + 10^- 7.7 + 10^- 7.7 ) =Combining 12 Flanking STC values
Combining Direct STC with 12 Flanking STC values

56

Page 89 of 102

Chapter 4: Predicting Sound Transmission in CFS-Framed Buildings

Summary for Section 4.2: Calculation Examples for CFS-Framed Constructions
The worked examples (4.2-H1 to H5 and 4.2-V1 to V2) illustrate the use of the Simplified
Method for calculating the apparent sound transmission class (ASTC) ratings between rooms ina building with CFS-framed floor and wall assemblies.
The examples show the performance for five cases with a e gypsum concrete floor surfaces(Examples 4.2-H1 to H4 and 4.2-V1) and for two cases with improvements in direct and/or
flanking transmission loss via specific paths due to the addition of typical finish flooring.
For a horizontal room pair, comparing pairs of examples shows the effect of changing key
details of the wall/floor junctions: Comparing Example H1 vs. Example H2 shows the change from ASTC 46 to ASTC 55 when abreak is introduced in the gypsum concrete floor surface, for the case with joists
perpendicular to a loadbearing separating wall.
 Comparing Example H3 vs. Example H4 shows the even larger change from ASTC 39 to
ASTC 54 when a break is introduced in the gypsum concrete floor surface, for the case withfloor joists parallel to a non-loadbearing separating wall.
From these examples, it is clear that a break in the continuous gypsum concrete surface
significantly reduces flanking transmission, which raises the ASTC rating from the unacceptable
range to a level which should satisfy a majority of occupants.
Adding laminate flooring to the bare floor surface (Example H5 vs. H1) only slightly increases
the Flanking STC ratings for the floor paths, but as the floor paths limit the ASTC rating for theare configuration this small improvement is enough to raise the ASTC rating from 46 to 48,
above the minimum requirement of ASTC 47 in the 2015 edition of the National Building Codeof Canada.
For a vertical room pair, Example 4.2-V1 shows that the sound transmitted through all 12
flanking paths combined is slightly less than the sound transmitted via the separating floor
assembly (Total Flanking STC rating of 59 vs. Direct STC rating of 57). Hence, the ASTC rating of
55 is dominated by the STC rating of the separating floor. Adding finished flooring in Example
V2 increases the Direct STC by 2 points to STC 59, and the ASTC increases to 56.

Page 90 of 102

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Appendices of Sound Transmission Data

5 Appendices of Sound Transmission Data
This Appendix presents one-third octave band sound transmission loss data, measured according to the
ASTM standard E90, for the CFS-framed wall and floor assemblies used in this Report.
Details of the test facilities and the measurement procedures are given in Chapter 2.
The test reports with detailed construction descriptions and results are provided in separate reports[13.7, 13.8, 13.9].

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Page 91 of 102

Appendices of Sound Transmission Data

5.1 Appendix A1: Transmission Loss Data for CFS-Framed Wall and Floor
Assemblies
Table A1.1(a): Sound transmission loss data for CFS-framed wall assemblies with a single row ofloadbearing CFS studs1 with a cross section of 38 x 152 mm, as described in Section 2.1.
Specimen CodeDescription

Steel
(mm)

CFS-S152-W01

G16_SS152(406)_GFB152_G16

1.37

19

18

12

13

19

27

32

38

36

CFS-S152-W02

G16_SS152(406)_GFB152_2G16

1.37

23

20

15

16

21

30

37

41

38

CFS-S152-W03

2G16_SS152(406)_GFB152_2G16

1.37

25

21

17

17

24

33

40

43

40

CFS-S152-W11

G16_SS152(406)_RC13(406)_G16

1.37

16

13

9

14

21

23

29

35

37

CFS-S152-W12

2G16_SS152(406)_RC13(406)_G16
G16_SS152(406)_RC13(406)_2G16
2G16_SS152(406)_RC13(406)_2G16
G16_SS152(406)_GFB92_RC13(406)_G16
2G16_SS152(406)_GFB92_RC13(406)_G16
2G16_SS152(406)_GFB92_RC13(406)_2G16
G16_SS152(406)_GFB152_RC13(406)_G16
2G16_SS152(406)_GFB152_RC13(406)_G16
2G16_SS152(406)_GFB152_RC13(406)_2G16
2G13_SS152(406)_GFB152_RC13(406)_2G13
G16_SS152(610)_GFB92_RC13(406)_G16
2G16_SS152(610)_GFB92_RC13(406)_G16
2G16_SS152(610)_GFB92_RC13(406)_2G16
2G16_SS152(610)_GFB152_RC13(406)_2G16
G16_SS152(406)_GFB152_RC13(406)_G16
2G16_SS152(406)_GFB152_RC13(406)_G16
2G16_SS152(406)_GFB152_RC13(406)_2G16

1.37

17

13

13

20

28

29

33

40

42

1.37

18

15

15

21

28

29

34

41

43

1.37

16

14

20

26

34

34

38

45

47

1.37

16

14

11

18

28

31

35

42

45

1.37

17

15

16

24

33

36

39

46

48

1.37

16

18

22

31

39

42

45

50

51

1.37

18

15

13

17

27

31

36

43

46

1.37

17

14

16

22

32

37

40

47

50

1.37

17

18

22

28

37

43

45

51

53

1.37

17

16

19

27

36

41

45

50

51

1.37

15

14

12

20

31

34

40

44

45

1.37

15

16

18

26

36

38

44

47

47

1.37

13

20

25

32

41

46

49

52

51

1.37

15

20

27

33

43

45

50

52

52

1.09

18

14

13

19

29

31

37

43

46

1.09

18

14

17

24

34

36

42

46

49

1.09

16

18

23

31

39

41

47

52

53

CFS-S152-W13
CFS-S152-W14
CFS-S152-W21
CFS-S152-W22
CFS-S152-W23
CFS-S152-W31
CFS-S152-W32
CFS-S152-W33
CFS-S152-W34
CFS-S152-W41
CFS-S152-W42
CFS-S152-W43
CFS-S152-W44
CFS-S152-W51
CFS-S152-W52
CFS-S152-W53

Page 92 of 102

63 Hz

125 Hz250 HzApparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Appendices of Sound Transmission Data

(Continuation of Table A1.1(a) from opposite page):

500 HZ

1000 HZ

2000 HZ

4000 HZ

STC

Reference

40

43

47

47

51

53

50

44

39

42

47

52

42

TLA-14-051

42

45

49

49

53

56

54

47

44

46

52

57

45

TLA-14-052

43

47

50

50

54

57

56

50

48

51

56

61

48

TLA-14-053

39

43

48

50

51

53

52

44

39

45

50

54

42

TLA-14-047

43

48

52

53

55

57

56

48

45

51

56

59

47

TLA-14-048

44

48

52

53

55

57

57

49

46

51

57

61

48

TLA-14-050

48

52

56

56

57

60

60

53

52

57

62

65

53

TLA-14-049

49

52

54

55

57

59

58

49

45

48

53

56

49

TLA-14-044

50

54

57

57

59

62

60

53

50

53

58

61

53

TLA-14-045

53

57

59

59

60

63

63

57

55

59

63

67

57

TLA-14-046

48

53

55

57

60

61

57

48

45

49

54

56

49

TLA-14-041,054,055

51

54

57

59

62

66

63

54

50

54

59

61

54

TLA-14-056

54

56

58

60

63

66

64

57

55

59

64

67

58

TLA-14-042,057,059

54

57

59

59

61

63

64

62

55

57

62

65

57

TLA-14-043

49

52

55

58

61

63

60

51

46

50

55

58

50

TLA-14-063

51

54

57

59

63

66

64

57

51

54

59

62

55

TLA-14-064

55

57

60

63

67

69

68

60

57

60

65

68

59

TLA-14-065

56

58

61

64

67

69

68

59

56

60

65

68

60

TLA-14-066

51

54

57

59

62

61

59

49

46

50

54

56

50

TLA-14-074

53

57

59

60

63

64

62

52

50

54

59

61

54

TLA-14-075

56

60

61

63

66

66

66

56

55

59

64

67

58

TLA-14-076

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Page 93 of 102

Appendices of Sound Transmission Data
Table A1.1(b): Sound transmission loss data for CFS-framed wall assemblies with a single row ofloadbearing CFS studs1 with a cross section of 38 x 92 mm, as described in Section 2.1.
Specimen CodeDescription

CFS-S92-W01
CFS-S92-W02

G16_SS92(406)_GFB92_G16

CFS-S92-W11

Steel
(mm)

63 Hz

125 Hz250 Hz

1.37
0.94

22
23

17
20

16
21

15
13

14
16

17
28

29
39

37
41

39
45

2G13_SS92(406)_RC13(610)_2G13

0.94

18

17

22

22

27

29

37

41

44

CFS-S92-W12

2G16_SS92(406) _RC13(610)_2G16

0.94

17

17

23

23

30

31

39

43

45

CFS-S92-W21

G16_SS92(406)_GFB92_RC13(406)_G16
G16_SS92(406)_GFB92_RC13(406)_2G16
2G16_SS92(406)_GFB92_RC13(406)_G16
2G16_SS92(406)_GFB92_RC13(406)_2G16
2G16_SS92(406)_GFB92_RC13(406)_2G16
2G13_SS92(406)_GFB92_RC13(406)_2G13
2G13_SS92(406)_MFB89_RC13(406)_2G13
G13_SS92(406)_GFB92_RC13(406)_G13
G13_SS92(406)_GFB92_RC13(406)_2G13
G13_SS92(406)_MFB89_RC13(406)_2G13
G13_SS92(406)_CFL92_RC13(406)_2G13
G13_OSB12_SS92(406)_MFB89_RC13(406)_2G13
2G13_SS92(406)_GFB92_RC13(406)_2G13
G16_SS92(406)_GFB92_RC13(406)_2G16
2G16_SS92(406)_GFB92_RC13(406)_2G16
G13_SS92(610)_MFB89_RC13(406)_2G13
G13_SS92(406)_GFB92_RC13(610)_G13
G13_SS92(406)_GFB92_RC13(610)_2G13
G13_SS92(406)_MFB89_RC13(610)_2G13
2G13_SS92(406)_GFB92_RC13(610)_2G13
G16_SS92(406)_GFB92_RC13(610)_G16
G16_SS92(406)_GFB92_RC13(610)_2G16
2G16_SS92(406)_GFB92_RC13(610)_2G16

1.37

20

17

14

12

21

28

34

42

45

1.5

20

18

18

20

26

33

40

46

51

1.37

22

18

15

18

28

34

39

45

50

1.37

21

16

16

25

34

39

44

49

53

1.5

20

16

21

27

33

39

45

50

54

1.5

20

18

20

24

33

38

44

49

54

1.5

21

18

18

24

32

38

44

49

54

0.94

17

16

13

14

21

27

36

41

45

0.94

19

17

15

20

27

32

40

46

50

0.94

21

17

18

20

27

34

42

48

53

0.94

21

17

16

19

27

33

41

47

50

0.94

20

16

21

26

33

38

45

51

55

0.94

19

18

20

25

33

38

44

50

54

0.94

20

17

18

21

27

34

41

46

51

0.94

18

18

22

27

35

40

45

51

55

0.94

17

15

19

25

31

37

44

48

53

0.94

15

14

13

19

23

28

36

42

45

0.94

18

16

15

22

30

33

41

46

50

0.94

20

16

17

22

28

35

42

48

53

0.94

17

17

20

29

36

39

45

51

54

0.94

16

14

13

19

26

29

37

43

47

0.94

18

17

16

23

31

35

41

47

51

0.94

18

20

23

29

38

42

46

51

55

CFS-S92-W22
CFS-S92-W23
CFS-S92-W24
CFS-S92-W25
CFS-S92-W26
CFS-S92-W27
CFS-S92-W31
CFS-S92-W32
CFS-S92-W33
CFS-S92-W34
CFS-S92-W35
CFS-S92-W36
CFS-S92-W37
CFS-S92-W38
CFS-S92-W41
CFS-S92-W51
CFS-S92-W52
CFS-S92-W53
CFS-S92-W54
CFS-S92-W55
CFS-S92-W56
CFS-S92-W57

Page 94 of 102

G13_SS92(406)_MFB89_2G13

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Appendices of Sound Transmission Data
(Continuation of Table A1.1(b) from opposite page):

500 HZ

1000 HZ

2000 HZ

4000 HZ

STC

Reference

38
50

38
53

45
55

44
57

48
60

49
60

49
62

41
59

37
50

41
49

46
53

51
56

38
40

TLA-14-073
TLA-99-133a

47

50

53

56

59

62

63

60

52

52

58

60

50

TLA-00-063a

48

52

55

58

59

61

59

52

50

55

61

63

51

TLA-00-075a

48

52

53

56

61

62

59

49

47

50

55

57

45

TLA-14-067

54

57

60

62

63

63

59

50

48

54

58

61

50

TLA-00-083a

52

54

55

57

62

64

63

55

51

54

60

62

52

TLA-14-068

55

55

56

60

64

66

66

58

55

59

65

68

57

TLA-14-069

58

61

62

64

65

66

63

55

53

59

62

65

57

TLA-00-085a

58

59

61

64

66

67

67

65

56

56

61

63

57

TLA-00-079a

59

60

62

65

66

67

68

66

57

58

62

64

56

TLA-00-081a

50

53

57

60

62

63

63

62

50

48

52

56

45

TLA-00-105a

55

58

61

63

64

65

65

64

53

52

57

61

51

TLA-00-103a

58

61

65

68

69

70

71

69

59

57

62

65

51

TLA-99-127a,129a

56

59

62

65

66

66

66

65

54

55

59

61

51

TLA-00-067a

60

64

67

69

70

72

73

71

62

62

68

70

57

TLA-99-135a

58

60

63

65

66

66

67

66

56

56

61

64

57

TLA-00-065a,101a

55

58

62

63

63

63

61

52

49

55

59

60

51

TLA-00-069a

58

61

65

66

65

66

64

56

55

60

64

65

58

TLA-00-071a

58

63

66

69

71

72

72

68

57

56

61

65

55

TLA-99-137a

50

54

57

60

63

64

64

62

49

48

52

56

47

TLA-00-095a

54

58

61

63

65

65

66

65

53

53

58

61

54

TLA-00-097a

58

62

65

68

69

70

71

69

60

57

62

64

52

TLA-99-123a

57

61

63

65

67

67

68

67

58

58

63

66

59

TLA-00-099a

50

54

58

60

62

62

60

51

46

51

55

57

49

TLA-00-089a

55

58

61

63

64

64

62

55

51

57

61

63

54

TLA-00-091a

58

62

64

66

67

66

65

58

56

61

65

67

59

TLA-00-073a,093a

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Page 95 of 102

Appendices of Sound Transmission Data
Table A1.2: Sound transmission loss data for CFS-framed floor assemblies with CFS joists of various
dimensions and spacing as described in Section 2.2.
Specimen
Code

Description

Steel
(mm)

63 HZ

125 Hz250 HzCFS-J317-F01 GCON32_CORSTE14_SJ317(406)_
GFB92_RC13(305)_G16

1.37

24

22

25

30

39

42

45

49

52

CFS-J317-F02 GCON32_CORSTE14_SJ317(406)_
GFB92_RC13(305)_2G16

1.37

26

27

30

36

44

47

48

53

56

CFS-J254-F01 GCON32_CORSTE14_SJ254(406)_
GFB92_RC13(305)_G16

1.37

23

25

29

30

36

41

47

47

54

CFS-J254-F02 GCON32_CORSTE14_SJ254(406)_
GFB92_RC13(305)_2G16

1.37

23

31

34

33

39

44

50

50

58

CFS-J254-F03 GCON32_CORSTE14_SJ254(406)_
GFB92_RC13(305)_G13

1.37

21

24

28

29

36

41

45

46

54

CFS-J254-F04 GCON32_CORSTE14_SJ254(406)_
GFB92_RC13(305)_2G13

1.37

24

30

32

34

40

44

48

50

57

CFS-J203-F01 CON40_CORSTE15_SJ203(406)_
RC13(406)_2G13

1.22

26

33

40

40

45

49

52

53

57

CFS-J203-F02 CON40_CORSTE15_SJ203(406)_
GFB90_RC13(406)_2G13

1.22

28

39

42

46

49

55

58

59

61

CFS-J203-F03 CON40_CORSTE15_SJ203(406)_
MFB90_RC13(406)_2G13

1.22

28

36

40

44

50

54

57

58

62

CFS-J203-F04 CON40_CORSTE15_SJ203(406)_
CFL200_RC13(406)_2G13

1.22

30

41

45

47

52

56

59

61

63

CFS-J203-F05 CON40_CORSTE15_SJ203(406)_
CFS130_RC13(406)_2G13

1.22

28

38

42

45

50

54

58

60

62

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Appendices of Sound Transmission Data
(Continuation of Table A1.2 from opposite page):

500 HZ

1000 HZ

2000 HZ

4000 HZ

STC

Reference

53

52

53

56

59

60

60

57

58

61

66

68

56

TLF-14-063,067

57

56

56

60

62

63

64

62

64

67

71

73

60

TLF-14-066

53

53

54

56

58

62

62

58

59

61

67

69

57

TLF-14-050,059

56

58

58

60

61

64

65

61

63

66

72

74

60

TLF-14-046,048,049

53

54

54

56

58

62

63

63

58

59

65

67

56

TLF-14-061

56

57

57

59

61

65

66

66

62

65

71

73

60

TLF-14-062

54

56

61

62

63

69

71

73

71

74

77

81

62

TLF-03-009a,011a

60

61

63

67

70

74

78

79

77

79

82

85

68

TLF-03-005a

60

62

64

68

70

74

77

78

76

78

81

85

68

TLF-03-007a

62

64

65

69

73

75

79

79

78

80

83

87

70

TLF-03-031a

60

60

63

68

72

75

79

81

80

82

85

89

68

TLF-03-039a

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

Page 97 of 102

References and Explanatory Notes

6 References and Explanatory Notes
Technical Standards
1. ASTM E90-09, Standard Test Method for Laboratory Measurement of Airborne Sound Transmission
Loss of Building Partitions and Elements , ASTM International, West Conshohocken, PA, USA.
2. ASTM E336-10, “ta da d Test Method for Measurement of Airborne Sound Insulation in Buildi gs ,ASTM International, West Conshohocken, PA, USA.
3. Other ASTM standards referenced and used in ASTM E90 and E336 include: ASTM E413-10,
Classifi atio for Rating Sound I sulatio
and ASTM E2235“ta da d Test Method fo
Determination of Decay Rates for Use in Sound Insulatio Test Methods , ASTM International, WestConshohocken, PA, USA.
4. ISO 717:2013, A ousti s—Rating of sound insulation in buildings and of building elements—Part 1:
Airborne Sound Insulation, Part 2: Impact Sound Insulation International Organization forStandardization, Geneva.
5. ISO 10140:2011, Parts 1 to 5, La o ato measurement of sound insulation of building ele e ts ,International Organization for Standardization, Geneva. Note: In 2011 the ISO 10140 series replaced
ISO 140 Parts 1, 3, 6, 8, 10, 11 and 16.
6. ISO 10848:2006, Parts 1 to 4, Laboratory measurement of flanking transmission of airborne andimpact sound between adjoining rooms , International Organization for Standardization, Geneva.
7. ISO 15712:2005, Part 1, Estimation of acoustic performance of buildings from the performance ofelements , International Organization for Standardization, Geneva.

Other Technical References
8. L. Cremer and M. Heckl, “t u tu e-borne sou d , edited by E.E. Ungar, Springer-Verlag, New York(original edition 1973, 2nd edition 1996).
9. E. Gerretsen, Cal ulatio of the sound transmission between dwellings by partitions and flanking
st u tu es , Applied Acoustics, Vol. 12, pp 413-433 (1979), and Cal ulatio of airborne and impact
sound insulation between dwellings , Applied Acoustics, Vol. 19, pp 245-264 (1986).
10. R.J.M. Craik, “ou d transmission through buildings: Using statistical energy a al sis , Gower
Publishing (1996).
11. D.B. Pedersen, Evaluation of EN 12354 part 1 and 2 for Nordic Dwelling Houses , Applied Acoustics,
Vol. pp 259-268 (2000), (Validation and background studies for the ISO 15712 procedures).

Sources for Sound Transmission Data
Source references for sound transmission data (both collections of conventional laboratory test results
for wall and floor assemblies according to ASTM E90, and flanking transmission tests following theprocedures of ISO 10848) including many NRC Construction reports in the RR- and IR- series areavailable from the Publications Archive of the National Research Council Canada at http://nparc.cistiicist.nrc-cnrc.gc.ca/npsi/ctrl?lang=en.

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References and Explanatory Notes
12. The software application soundPATHS is accessible online at the website of the National ResearchCouncil Canada. The calculations are based on experimental studies in the laboratories of the NRC:
http://www.nrc-cnrc.gc.ca/eng/solutions/advisory/soundpaths/index.html
13. Technical details concerning the measurement protocol (consistent with ISO 10848) and discussionof the findings of the experimental studies are presented in a series of NRC reports:
13.1. IR-754, Flanking Transmission at Joints in Multi-Family Dwellings. Phase 1: Effects of Fire
Stops at Floor/Wall Intersections , T.R.T. Nightingale and R.E. Halliwell, (1997)
13.2. RR-103, Flanking Transmission in Multi-Family Dwellings Phase II: Effects of Continuous
Structural Elements at Wall/Floor Junctions , T.R.T. Nightingale, R.E. Halliwell, and J.D. Quirt(2002)
13.3. RR-168, Flanking Transmission at the Wall/Floor Junction in Multifamily Dwellings Quantification and Methods of Suppression , T.R.T. Nightingale, R.E. Halliwell, J.D. Quirt andF. King (2005)
13.4. RR-218, Flanking Transmission in Multi-Family Dwellings Phase IV , T.R.T. Nightingale, J.D.
Quirt, F. King and R.E. Halliwell, (2006)
13.5. RR-219, Guide for Sound Insulation in Wood Frame Construction , J.D. Quirt, T.R.T.
Nightingale, and F. King (2006). See also NRC Construction Technology Update 66, Ai o eSound Insulation in Multi-Family Buildi gs , J.D. Quirt and T.R.T. Nightingale (2008)
13.6. J. K. Richardson, J. D. Quirt, R. Hlady, Best Practice Guide on Fire Stops and Fire Blocks andtheir Impact on Sound Transmission , NRCC #49677 (2007)
13.7. IR, Sound Insulation of Load-Bearing Shear-Resistant Wood and Steel Stud Walls ,T.R.T. Nightingale, R.E. Halliwell, J.D. Quirt and J.A. Birta (2002)
13.8. RR, “ua Repo t for Consortium on Fire Resistance and Sound Insulation of
Floors: Sound Transmission and I pa t I sulatio Data , A.C.C. Wa o k
13.9. NRC Report A1-005007.1, Transmission Loss and Impact Insulation Data for Cold-Formed
Steel Framed Walls and Floors , C. Hoeller, B. Zeitler, and I. Sabourin (2017)
14. RR-331, Guide to Calculating Airborne Sound Transmission in Buildings (2nd Edition, 2016) is acompanion to this Report, which presents both the Detailed Method of ISO 15712-1 and the“i plified Method that is used in this Report for calculating sound transmission in buildings.
15. The databases of flanking transmission data used in Guide RR-331 and in soundPATHS will beconsolidated in a series of NRC publications presenting data from recent studies:15.1. RR-333 Apparent Sound Insulation in Concrete Buildings (2017)15.2. RR-334 Apparent Sound Insulation in Concrete Block Buildings (2015)
15.3. RR-335 Apparent Sound Insulation in Cross-Laminated Timber Buildings (2017)15.4. RR-336 Apparent Sound Insulation in Wood-Framed Buildings (2017)15.5. RR-337 Apparent Sound Insulation in Cold-Formed Steel (CFS) Framed Buildings (2017)

Scientific Research Papers Published as Part of this Study:
16. The following scientific research papers were published as part of this study:
16.1. C. Hoeller, B. Zeitler and J. Mahn, Direct Sound Transmission Loss of Heavy Gauge SteelStud Walls , EURONOISE 2015
Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

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References and Explanatory Notes
16.2. C. Hoeller, B. Zeitler, and I. Sabourin, Direct airborne and impact sound insulation of steelframed floors for mid-rise constructions , INTERNOISE 2015
16.3. C. Hoeller and B. Zeitler, Laboratory Study on Flanking Sound Transmission in Cold-Formed
Steel-Framed Constructions , INTERNOISE 2016

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Apparent Sound Insulation in CFS-Framed Buildings
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References and Explanatory Notes

1 Cold-formed steel (CFS) framing includes floor joists and wall studs that are made from sheet steel into
standard profiles by roll-forming the steel sheets through a series of dies. The process does not require
heat to form the profiles, hence the name cold-formed steel. Joists and studs are available in a variety ofsteel thicknesses, for applications in loadbearing and non-loadbearing walls and floors. In this Report,
data is provided for loadbearing steel framing formed from sheet steel with thickness of 1.37 mm andnon-loadbearing steel framing formed from sheet steel with thickness of 0.54 mm.

2 Gypsum board panels commonly form the exposed surface on lightweight framed wall or floor
assemblies and on linings for heavy homogeneous structural wall or floor assemblies of concrete,concrete block or CLT. The gypsum board in this study had nominal thickness of 12.7 mm (1/2 inch) or
15.9 mm (5/8 inch) denoted in specimen codes as 13 mm and 16 mm respectively.
Fire- ated g psu
oa d is t pi all hea ie tha o -fire-rated gypsum board. The higher mass perarea of the fire-rated gypsum board gives improved resistance to sound transmission through theassembly. The des ipto fi e- ated is used in this Report to denote gypsum board with proven fireresistant properties, with mass per unit area of at least 8.7 kg/m2 for 12.7 mm thickness, or 10.7 kg/m2
for 15.9 mm thickness. Gypsum board panels are installed with framing, fasteners and fastener spacing
conforming to installation details required by CSA A82.31-M or ASTM C754. The sound transmission
results should only be used where the actual construction details correspond to the details of the test
specimens on which the ratings are based.

3 Sound absorbing material is porous (closed-cell foam is not included) and readily-compressible, andincludes fiber processed from rock, slag, glass or cellulose fiber. Such material provides acousticalbenefit for direct transmission through lightweight framed wall or floor assemblies, and for flanking
transmission when installed in the cavities between lining surfaces and heavy homogeneous structuralelements. Note that overfilling the cavity could diminish the benefit of the sound absorbers.

4 Resilient metal channels are formed from steel with a maximum thickness of 0.46 mm (25 gauge), witha profile essentially as shown in Figure 6. , ith slits o holes i the si gle leg et ee the fa es
fastened to the framing and to the gypsum board. Installation of the resilient channels must conform to
ASTM C754.

Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017

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References and Explanatory Notes

Figure 6.1: Drawing to illustrate the typicalprofile of resilient metal channels;
approximate dimensions in cross-section
are 13 mm x 60 mm (not precisely to scale).
(Copied from Figure A-9.10.3.1 of the
National Building Code of Canada, usedwith permission)

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Apparent Sound Insulation in CFS-Framed Buildings
1st edition – April 2017