Cost and Time Study 

for Constructing Raised 

Wood Floor Systems in 

the Gulf Coast Region of 

the United States 

Marie Del Bianco

David B. McKeever

Lance Barta

United States

Department of

Agriculture

Forest Service

Forest

Products

Laboratory

Research

Paper

FPL–RP–664
February 2012

Del Bianco, Marie; McKeever, David B.; Barta, Lance. 2012. Cost and 

time study for constructing raised wood floor systems in the gulf coast 

region of the United States. Research Paper FPL-RP-664. Madison, WI: 

U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 18 p.

A limited number of free copies of this publication are available to the 

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Abstract

This report is the result of a co-operative effort between the 

USDA Forest Service, Forest Products Laboratory (FPL) 

Advanced Housing Research Center, the National Association of Home Builders (NAHB) Research Center, and 

builder members of the Metropolitan Mobile and Baldwin 

County Home Builders Associations. The study was undertaken to further knowledge that will improve wood utilization and performance in wood-framed housing, specifically 

in the area of wood raised floor design and wood usage in 

the Gulf Coast region of the country.

Keywords: floor systems, raised wood floors, Gulf Coast, 

residential construction, construction costs, construction 

time, cost comparisons

Acknowledgment

This research was supported by funds provided by the Forest Products Laboratory located in Madison, Wisconsin. 

Alabama builders B.C. Daniels, Inc., and Hons Builders, 

Inc., provided the designs, sites, materials, and construction 

teams for the foundations featured in this case study. Thank 

you to Randall A. Cantrell, Ph.D., Manager of Innovation 

Research, and John Peavey, Director of Applied Technology, 

at NAHB Research Center, Upper Marlboro, Maryland, for 

their support throughout the course of the study and their 

review of the paper.

Conversion Table

English unit Conversion factor SI unit

foot (ft) 0.3048 meter (m)

pounds per square 

 foot (lb/ft2)

47.880 pascal (Pa)

cubic yard (yd3) 0.7646 cubic meter (m3)

square feet (ft2) 0.092903 square meter (m2)

Contents

Executive Summary..........................................................i

Introduction.......................................................................1

Approach...........................................................................1

Background.......................................................................1

 Foundation Design from the Ground Up ......................1

 Foundations Investigated ..............................................2 

 Case Specifics ...............................................................3

Cost Considerations..........................................................3

 Recognized Costs..........................................................3

 Unrecognized Costs......................................................3

 Cost Comparison...........................................................5

Time to Construct..............................................................7

 Construction Critical Path Schedules............................7

 Time ..............................................................................7

Results...............................................................................7 

Value Engineering Strategies............................................8

 Competitive Bids ..........................................................8 

 Optimize Floor Systems................................................8 

 Continuous Versus Spot Footings.................................9 

 Alternative Piers............................................................9

 Lower Piers to Allow In-Line Framing.........................9

 Reduce Interior Supports at Design Stage ....................9

 Pier Spacing ..................................................................9 

 Minimize Waste with a Bill of Materials and 

 Cut List..........................................................................9 

 Promote the Attributes of a Crawl Space.................... 10

Optimized Case with Value Engineered Strategies......... 10

Conclusion ...................................................................... 11

References....................................................................... 11

Appendix A. Relevant Indices ........................................ 12

Appendix B. Detail on Cost—Raised Wood................... 13

Appendix B. Detail on Cost—Raised Concrete with 

Stem Wall Foundation..................................................... 14

Appendix B. Detail on Cost—Raised Concrete on 

Compacted Fill Pad......................................................... 15

Appendix C. Detail on Time to Construct ...................... 16

Appendix D. Detail on Hypothetical Costs with Key 

Cost Components Set Equal............................................ 17
Executive Summary

This study was undertaken to further knowledge about 

wood utilization and performance in wood-framed housing, 

specifically raised wood floor foundation design. The study 

focused on several foundation and elevated first floor systems common to the Gulf Coast region, including two raised 

concrete slab systems: raised concrete slab on fill within 

stem wall, and raised concrete slab on fill pad. These were 

compared with a raised wood floor system on stem wall 

with a crawl space. While not the most cost-effective raised 

wood floor foundation system, we chose the stem wall system because the builders participating in the study preferred 

them. Cost and time considerations involved in constructing 

each of these foundations were reported for nine builder 

case studies, including four raised wood floors on stem wall 

foundations, two raised concrete slabs on compacted fill 

pads, and three raised concrete slabs on stem wall foundations and compacted fill. Table A covers the average costs of 

the three foundation and floor assembly construction types.

As anticipated at the outset, a raised concrete slab on a compacted fill pad had the least total cost and the shortest time 

to construct. However, the average wall height of the two 

slabs on fill pads was less than 2 ft, which is the prescriptive 

building code’s height limit for this design and a lower average elevation than was required for the topography of the 

other seven house designs on the lots in this study. A slab 

on a fill pad does not require a footing or perimeter walls 

because a turned down, thickened, and reinforced haunch 

shaped by a trench and slab form serves the two functions at 

the slab edge. It also takes up more lot space because of the 

sloped fill pad extensions on all sides of the foundation.

The three raised concrete slabs on compacted fill retained 

within perimeter stem wall foundations averaged 3 ft in 

height with first floors sized similarly to the slabs on fill 

pads. There was an average cost of $7,400 more for the additional 1 ft, 3 in. of foundation wall height, compared with 

slabs on compacted fill. The raised wood systems cost an 

average of 27% more than the raised concrete on fill with 

stem wall (as measured by average total cost). The difference in average elevation of the foundation walls supporting 

the two floor types was approximately 4 in. (wood measures 

3 ft, 5 in., whereas concrete measures 3 ft, 1 in.).

Wall height was a cost driver in the foundations, and the 

study reflects that by reporting in cost per square foot of 

foundation wall. However, the cost per square foot of stem 

wall foundation declined as the wall got higher because the 

cost of the footing was spread over more area. Footings and 

foundations of the two raised floor systems with stem walls 

could be constructed with equal cost, but interior piers and 

crawl space foundation accessories (vents and access panels) will add cost to the raised wood floor system. Given a 

defined base flood elevation floor height requirement, there 

should be no difference in cladding volumes between the 

two systems, provided finished floor heights are designed to 

be at the same elevation.

Floor joist and girder costs of the raised wood were on par 

with the cost of the concrete slab, as were sheathing and 

insulation costs compared with the fill dirt and compaction, 

but there was a disparity between the cost of carpentry labor 

and that of slab labor. This contributed to the cost difference 

between the two systems.

An optimized cost approach is presented to normalize the 

variance in wood floor labor and material costs borne by the 

builders in the study. The optimized approach results in an 

average cost difference of $2.53 per square foot of foundation wall between wood and concrete on stem walls at the 

given average foundation heights.

The study relied on project homes volunteered by builders, 

and the cost comparison is based on regional costs of key 

components such as concrete, lumber, concrete masonry 

units, and the associated trade’s labor rates, as reported in 

this study. Potentially less costly foundations, such as pierand-beam raised wood floor foundations, were not investigated.

i

Table A—Average installed cost of foundations 

Component

Raised wood floor

on stem wall 

crawl space 

Raised concrete

on fill 

in stem wall 

Raised concrete 

on compacted 

fill pad 

Total cost ($) 23,752 18,691 11,267 

Average foundation height (ft) 3.42 3.08 1.79 

Footing (linear ft) 206 237 217 

Average cost of foundation ($/ft2

) 34.14 25.82 29.10 

Average of 1st floor (ft2

) 1,966 2,292 2,275 

Average cost of 1st floor ($/ft2

) 12.08 8.15 4.95 a

Optimized raised wood floor system. Use Appendix D assumptions. See Value Engineering section 

for more information. 

b

Established minimum stem wall height.
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Introduction

Numerous foundation designs exist for new residential 

buildings, including full foundation with basement; full 

foundation with crawl space; raised floor system on posts, 

piers, or pilings; slab-on-grade; raised slab on compacted 

fill; and various other combinations. Choosing a specific 

foundation type involves assessing desired functionality, 

aesthetics, and cost. In the Gulf Coast region of the United 

States, base flood elevation (BFE) may dictate height of 

the first floor to avoid potential damage or destruction from 

flooding. Sloped topography and architectural features such 

as porches or outdoor decks also drive demand for a raised 

first floor.

Two common construction methods used in the Gulf Coast 

region to achieve an elevated first floor are the raised concrete slab and the raised wood floor stem wall system. This 

study endeavored to examine and capture as many cost considerations involved in constructing these foundation types 

as was feasible. The study was conducted as a series of case 

studies on sites selected by each builder. Nine foundations 

were evaluated—four raised wood floors on stem wall foundations, two raised concrete slabs on compacted fill pads, 

and three raised concrete slabs on stem wall foundations 

and compacted fill.

Statistical data compiled for the East South Central census 

area of the country, the region of this study’s focus, indicates 

that 67% of the newly constructed single-family houses that 

were built during 2008 consisted of concrete slab first floors 

and 29% consisted of wood floors on basement or crawl 

space foundations (approximately evenly split between 

basements and crawl spaces). In the NAHB Research Center, 2008 annual builder practices survey, results indicated 

the following: slab 67%, crawl space (stem wall) 15%, 

basements 14%, other (pier or mixed basement/crawl/slab 

construction) 4%. See http://www.census.gov/geo/www/

us_regdiv.pdf for defined area.

Approach

The NAHB Research Center and two associations representing wood product manufacturers solicited participation of 

builders in the Gulf Coast region for this study. Cost data 

relevant for constructing houses to the top of their first floor 

were recorded for nine house sites in Alabama. The first 

floors for four of the houses were built with wood framing and five were built with concrete slabs. Three of the 

five concrete slab floors were formed with perimeter stem 

walls, similar to the wood floor assemblies. The stem walls 

retained compacted fill material for support of the concrete 

slabs. The two remaining concrete slabs were supported on 

compacted fill pads.

Costs represent work that progressed during a 2-year time 

period and are reported as the amount on the invoices rendered at the time the houses were built, including taxes and 

incidental fees, such as delivery and fuel surcharges. Appendix A contains relevant costs for materials as a point of 

reference for the reader.

For eight of the foundations/floor systems in this study, invoices rendered for the activities that were associated with 

footing, foundation, and first floor assembly were audited 

and logged. The cost for a ninth house, Lot 2J, was estimated from quotes and quantity take-offs, as construction was 

in progress at the time this report was completed. For all but 

the ninth house, delivered quantities were verified against 

installed quantities, and quantity take-offs were estimated 

from blueprint drawings.

At several of the sites, labor time studies were conducted to 

observe the construction process from footing excavation 

through the finish of the first floor. The builders’ construction schedules provide the timeline for other lots.

Background

Foundation Design from the Ground Up

The house foundation and footing system serves a number 

of purposes. It bears the weight of a building’s loads and 

safely transfers these to the ground, provides the restraint 

against wind and earthquake forces, prevents movement due 

to frost heave, isolates a building from ground moisture, and 

provides a safe pathway to transfer electrical current generated during lightning strikes into the earth.

Each of the most common types of foundations used to 

support light frame wood buildings, slab, crawl space, and 

basement may be constructed in several ways to accommodate cost, climate, and site conditions. For example, 

Cost and Time Study for Constructing 

Raised Wood Floor Systems in the Gulf 

Coast Region of the United States

Marie Del Bianco, Building Analyst, NAHB Research Center, Upper Marlboro, Maryland

David B. McKeever, Research Forester, Forest Products Laboratory, Madison, Wisconsin 

Lance Barta, Research Engineer, NAHB Research Center, Upper Marlboro, Maryland
Research Paper FPL–RP–664

2

concrete slab foundations can be built on grade, on top of 

compacted fill material pads, or on top of compacted fill material retained within stem walls. Crawl space foundations 

may consist of continuous perimeter stem walls, piers and 

beams, or a combination of these. Basement foundations 

may be in-ground (full excavation), walkout (partial excavation within a sloped topography), or some variant of these. 

Each type of basement foundation typically is constructed of 

reinforced formed concrete and/or concrete masonry units 

(CMU). Slab foundations will have concrete first floors, 

whereas crawl space and basement foundations most commonly have wood first floor systems. The second floors of 

houses on any of these foundation types are typically wood 

systems.

Climate and soil conditions often guide selection of the 

foundation type. Regions with mild winter weather have 

shallow frost penetration of the soil that minimizes the footing depth required to resist soil movement from frost heave. 

Where local conditions and house design allow a 12- to 

18-in. deep footing, such as in the U.S. South, the decision to increase that excavation by 6 ft to 7 ft to include an 

in-ground basement foundation presents a substantial cost 

burden. In more northern climates where frost levels reach 

more than 48 in., the decision to incorporate additional 

square footage in a basement is based on a smaller incremental cost to complete than that of a southern region design, so basements are more prevalent. Similarly, challenging soil conditions can result in more expensive foundation 

systems, such as in parts of Texas where post-tension slab 

foundations are required to resist damage due to expansive 

clay soils.

Foundations Investigated

The subjects of this study were raised wood floors on stem 

wall crawl space foundations compared with two methods 

of construction of raised slab foundations. The raised wood 

floor systems on stem wall foundation were framed with 

either dimensional lumber or I-joists. In each of the cases 

represented, the builder’s team selected the foundation and 

floor system.

Figures 1 and 2 are stem wall foundations; each would be 

appropriate for either a raised wood floor or compacted fill 

and a raised concrete slab. The piers inside the perimeter 

stem walls of the foundation in Figure 1 will support girders 

supporting floor joists and other building loads. The excavated trenches in the compacted fill material within a stem 

wall foundation in Figure 2 will be filled with reinforcement 

bar (rebar) and concrete when the concrete slab is prepped 

and placed to serve as grade beams or depressed footings 

supporting interior building loads. Figure 3 shows the compacted fill prepared for the concrete slab placement.

The compacted fill inside a stem wall foundation, shown in 

Figures 2 and 3, is a design typically used when elevation 

difference between grade and finished floor is greater than 

2 ft for a ground-supported concrete slab floor. At elevations 

less than 2 ft above grade, raised slabs may be constructed 

on raised building pads created with compacted fill material 

as in Figures 4 and 5. However, the 2006 International Residential Code (IRC) and newer versions limit prescriptive 

slab construction on clean sand or gravel compacted fill to 

2 ft or less and earth compacted fill to 8 in.; this would require engineered designs for greater elevation variances.

Figure 1—Stem wall crawlspace foundation with interior 

piers, Lot 38.

Figure 2—Stem wall foundation with compacted fill, Lot 11.

Figure 3—Stem wall foundation with slab prepared for concrete placement, Lot 11.
Cost and Time Study for Constructing Raised Wood Floor Systems in the Gulf Coast Region of the United States

3

Case Specifics

Each house had a conditioned, finished, first floor sized between 1,680 and 2,370 ft2, and each was built on an infill lot 

within a developed or developing community. The elevation 

of each finished first floor that was a subject in this study 

varied from 8 to 72 in. (above finished grade), sometimes 

within the same house.

On all of the sites represented in the study, the site topography, estimated cost, assumed preferred consumer convention, specified finish flooring (tile or wood), or a combination of these factors guided the selection of foundation/

floor system design and type rather than base flood elevation 

(BFE) requirements.

Cost Considerations

Each lot was constructed according to the builder’s standard 

practices using subcontractors and suppliers in each company’s customary supply chain. Costs were compiled from 

the invoices rendered, and quantities were verified against 

field counts and/or quantity takeoffs. Tables 1, 2, and 3 

show the costs that have been compiled for the three types 

of foundations in the case study, raised wood on CMU stem 

wall, raised slab supported on compacted fill retained by a 

CMU stem wall, and raised slab on compacted fill pad.

Recognized Costs

Each of the foundations in the study was finished with a 

brick veneer. The footings below the stem wall foundations served as the brick ledge. At turned-down edges of 

the slabs constructed on compact fill pads, concrete was 

over-poured under the slab form to serve as the brick 

ledge. The cost and labor associated with the brick veneer 

of the foundation was not recorded with the cost of each of 

the foundations because it was a non-structural cosmetic 

finish.

The designs used dissimilar hardware for wind uplift force 

restraint. For example, one design specified that threaded 

bolts run continuously from grouted CMUs through the 

highest walls’ top plates, whereas another called for sill 

plate bolts with washers, stud/plate hardware (high and low) 

in each wall, and tie-down straps at headers. Hardware that 

was installed to complete the first floor is included in the 

reported costs.

Inspection fees paid to an engineer for testing the compacted 

fill beneath the slabs were included at the rate of $60 per lot, 

the average expense incurred. No special engineering fees 

directly associated with the foundation were charged. Each 

of the house plans was prepared by a professional draftsperson and reviewed and sealed by an engineer or architect. 

Standard foundation details from the 1999 Standard (southern) Building Code Congress International (SBCCI) were 

included in the architectural plans to represent the footing 

and grade beams, CMU walls, and compacted fill/slab designs. SBCCI is one of three original regional model building code development groups and a founder of the ICC, 

International Code Council, fiduciary of the I-code development process, and the International Residential Code.

The 2006 IRC, the building code governing the minimum 

construction standards for the houses in this study, requires 

that floors exposed to ambient conditions, as with a vented 

crawl space foundation, require R-13 insulation, whereas 

slab edges require no insulation in this climate zone (i.e., 

Climate Zone 2). Cost estimates for R-19 floor insulation 

(because that is what the builders installed in all cases), 

polyethylene vapor barrier, foundation vents, and a crawl 

space access door are included for each raised wood foundation. These activities tend to be completed toward the end 

of a building’s critical path of construction; thus, these costs 

were estimated if they had not been recorded when this 

study was completed.

In some cases, product or cost contributions were extended 

to the builders participating in the study. In this event, the 

builder’s cost of the product was estimated from current 

quotations and added to the total cost for the lot.

Unrecognized Costs

The perimeter walls, porches, and garage slabs from an attached garage have been omitted from the costs considered 

Figure 4—Compacted fill pad, Lot 18 rear.

Figure 5—Compacted fill pad prepared for concrete placement, Lot 18 front.
Research Paper FPL–RP–664

4

Table 1—Raised floor cost for wood on stem wall crawl space 

foundation

Cost and dimension data 

for four lot numbers Average

($)

Cost

38 39 2W 2J (%)

Footing ($) 

Concrete 3,669 3,277 1,296 2,407 2,662 11 

Labor 1,850 1,855 1,473 1,483 1,665 7 

Rebara 813 834 894 881 855 4 

Subtotal footing 6,332 5,966 3,663 4,771 5,183 — 

Foundation wall ($) 

Concrete 1,627 1,232 1,368 1,055 1,320 6 

CMUb 3,309 3,634 2,061 2,917 2,981 13 

Labor 2,344 3,197 2,176 1,550 2,317 10 

Subtotal foundation wall 7,280 8,064 5,605 5,522 6,618 — 

Floor system ($) 

Joists/girdersc 3,366 2,963 6,918 6,853 5,025 21 

Sheathingd

/insulation 2,871 3,228 2,742 3,183 3,006 13 

Labor 6,396 4,007 2,486 2,790 3,920 17 

Subtotal floor system 12,633 10,198 12,147 12,826 11,951 — 

Total ($) 26,245 24,228 21,414 23,119 23,752 100 

Average foundation height (ft) 3.84 3.79 2.67 3.38 3.42 — 

Footing (linear ft) 215 207 208 193 206 — 

Cost of foundation ($/ft2

) 31.71 30.82 38.66 35.37 34.14 — 

a

Rebar includes forms for jumps and rod chairs. 

b

CMU includes accessories, vents, and crawl space access. 

c

Joists include beams, hardware, and brick veneer. 

d

Sheathing includes subdeck insulation, R-19. 

Table 2—Raised floor cost for raised slab on fill within 

stem wall foundation

Cost and dimension

data for 

three lot numbers Average

($)

Cost

22 11 34 (%)

Footing ($) 

Concrete 1,574 2,356 2,252 2,060 11 

Labor 912 995 1,019 975 5 

Rebara 757 811 867 812 4 

Subtotal footing 3,243 4,162 4,137 3,848 —

Foundation wall ($) 

Concrete 1,136 1,999 1,189 1,441 8 

CMUb 2,458 2,793 2,070 2,440 13 

Labor 2,153 2,224 1,795 2,057 11 

Subtotal foundation wall 5,747 7,016 5,054 5,939 —

Floor system ($) 

Concrete 3,846 3,653 3,406 3,635 19 

Fillc 3,860 3,405 3,385 3,550 19 

Labor 1,692 1,777 1,688 1,719 9 

Subtotal floor system 9,398 8,836 8,479 8,904 —

Total ($) 18,388 20,014 17,670 18,691 100 

Average foundation height (ft) 2.89 3.47 2.87 3.08 —

Footing (linear ft) 228 249 233 237 —

Cost of foundation ($/ft2) 27.86 23.17 26.42 25.82 —

a

Rebar includes forms for jumps and rod chairs. 

b

CMU includes accessories. 

c

Fill includes compaction inspection. 
Cost and Time Study for Constructing Raised Wood Floor Systems in the Gulf Coast Region of the United States

5

in this study. The resultant focus is on the cost and time to 

construct raised floor systems within a conditioned building.

As previously stated, the costs reported for the foundations 

in this study do not include the cost of the brick veneer. Because these costs varied with lot condition and builder and 

were not specifically associated with any one foundation 

type represented in the study, we omitted from reporting approximately $2,200 to $3,000 of costs related to clearing the 

lot, locating the house on the lot, and treating the disturbed 

area for termites. Where excavation cost specifically related 

to the foundation was incurred, it has been included with the 

cost of the footing or the raised slab’s form work, consistent 

with the labor invoice for these activities.

All of the costs associated with development of the architectural design and reproduction of architectural drawings were 

also omitted from this study for similar reasons. Likewise, 

costs associated with components and activities that occur 

after the first floor is in place have not been captured or reported.

The installation costs associated with the rough mechanical, 

electrical, and plumbing (MEP) trades were not captured 

because, in all cases, these were charged at the same rate for 

either a slab or a crawl space with wood floor system design. A raised concrete slab on compacted fill with stem wall 

is the traditional foundation installed by the builders in this 

study, and therefore they have no learning curve to produce 

a low-cost product. The only MEP trade affected by a raised 

wood floor system installed in lieu of a slab on fill is the 

plumbing because piping is routed beneath the floor joists 

rather than in the fill material under a slab.

The environment and timing of the plumber’s ground and/

or rough-in work changes with foundation type—from 

working in the open air to operating within a confined crawl 

space. The slab requires three trips to the jobsite for the 

plumber: one to install water sleeve and sub-slab drains, one 

to complete the piping after the frame is under roof, and one 

to complete the fixtures when the house nears completion. A 

crawl space foundation, however, allows completion of all 

supply and drain pipes after the roof has been installed, paring the plumber’s activities to two site visits—rough-in and 

final. The other trades installed rough-in work in the same 

critical path and layout whether on a raised slab or raised 

wood floor system.

Cost Comparison

Each of the foundation/floor systems is divided into three 

distinct assemblies: footing, wall, and floor system. Each 

of these assemblies is comprised of a few key material and 

labor categories that will facilitate an examination of cost 

drivers across foundation types. Appendix B contains the 

cost detail by lot.

All of the CMU walls were reinforced with vertical rebar, 

horizontal Dur-O-Wall® sidewall belting (Dur-O-Wall 

Hauppauge, NY ), and each cell was grouted with concrete; 

thus, the concrete material in the “Foundation wall” section 

of Table 1 covers the cost of grout and the concrete pump. 

The CMU total in the same section includes the 

Table 3—Raised floor cost for raised concrete slab on 

compacted fill pad

Cost and 

dimension

data for 

two lot numbers Average

($)

Cost

21 18 (%)

Footing ($) 

Concrete — — — 0 

Labor — — — 0 

Rebar — — — 0 

Subtotal footing 0 0 0 —

Foundation wall ($) 

Concrete — — — 0 

CMU 479 281 380 3 

Labor — — — 0 

Subtotal foundation wall 479 281 380 —

Floor system ($) 

Concrete 6,581 6,132 6,356 56 

Fill 2,928 2,720 2,824 25 

Labor 1,707 1,706 1,706 15 

Subtotal floor system 11,216 10,557 10,887 —

Total ($) 11,696 10,838 11,267 100

Average foundation height (ft) 1.70 1.89 1.79 —

Footing (linear ft) 228 205 217 —

Cost of foundation ($/ft2

) 30.24 27.95 29.10 —
Research Paper FPL–RP–664

6

reinforcement material. The labor to grout the wall is included in the “labor” category along with the mason’s charge for 

laying the CMU.

Tables 2 and 3 indicate that the costs associated with the 

wood floors on stem wall foundations are the highest costs 

recorded in this study. As a test of the compiled costs’ reliability, they are compared with estimates derived from R.S. 

Means (2010) cost data, unadjusted for location, in Table 4. 

This table also includes information on the finished square 

footage, foundation square footage, and average foundation 

height of each house.

The comparison of actual costs to estimators’ guide costs 

indicates that actual costs of the wood floor systems were 

up to 20% more than would have been estimated (last row, 

“builder over RMS”; Lots 38, 39, 2W, and 2J), whereas 

the other five assembly costs came in below the construction estimation guide results. This would be expected, as 

the R.S. Means estimation guide includes a location factor 

adjustment of .81 for Mobile, Alabama. The numbers suggest that the wood floor assemblies could benefit from value 

engineering and competitive bidding; some of the areas that 

surfaced during the study will be covered in the Value Engineering Strategies section of this report.

The raised concrete slabs on fill within stem walls (Lots 22, 

11, and 34) actual costs range from 8% to 18% under the 

estimation guide, and the slabs on fill pads (Lots 21 and 18) 

range from 8% to 17% below the estimates.

The stem wall foundation for the raised wood floor system 

and for the concrete slab supported on compacted fill require 

essentially the same labor and material inputs prior to placement of the finished first floor, with either fill and concrete 

or wood and sheathing. The wood floor systems require 

interior footings and piers, for which costs are reflected 

in the “footing” and “wall” categories, respectively, in 

Table 1. The interior load support in both of the slab foundation types was installed as depressed footings below the slab 

and captured in the costs in the “floor” section of Tables 1 

and 2. Technically, there is no additional labor charge for 

the installation of depressed footings and turned down slab 

edges, which suffice for footings in slabs formed on compacted fill pads. Nor is there an additional charge for footing 

and foundation complexity, such as jump conditions and inside and outside corners. The builder pays for the concrete, 

pump, accessories (wire mesh, poly), and labor separately. 

The builders charge by finished square foot of slab and order 

and install the concrete and accessories without regard for 

cost effectiveness.

Under this type of cost scheme, the interior building load 

supports required for a raised wood floor system (interior 

footings, piers, and beams) will always stand out as added 

cost in comparison to a slab, because of the simplicity of 

accommodating interior loads engineered for concrete on 

compacted fill. As noted below Table 1, each of the raised 

wood floors on stem wall foundations “wall” totals includes 

vents, access panels, and polyethylene vapor barrier to finish 

the crawl space at a cost of $860. Thus “footing” and “wall” 

costs of raised slab and raised wood floors with stem wall 

foundations should vary by the cost of interior supports and 

crawl space finishing details in the wood-floored house.

Table 4—Comparison of costs with R.S. Meansa data

Lot 38 

Mobile, 

AL 

Lot 39 

Mobile,

AL 

Lot 22

Spanish

Fort, 

AL 

Lot 21

Spanish

Fort, 

AL 

Lot 2W

Daphne,

AL 

Lot 18 

Spanish 

Fort, 

AL 

Lot 11 

Spanish 

Fort, 

AL 

Lot 34

Spanish

Fort, 

AL 

Lot 2J 

Montrose,

AL, 

estimated

Type of foundation Stem wall Stem wall Stem wall Raised

pad slab 

Stem wall Raised 

pad slab 

Stem wall Stem wall Stem wall

1st floor material Wood Wood Concrete Concrete Wood Concrete Concrete Concrete Wood 

Construction start date 8/1/08 3/1/09 10/1/09 3/1/10 4/10/10 5/1/10 5/1/10 7/10/10 8/22/10 

Average foundation height (ft) 3.84 3.79 2.89 1.70 2.67 1.89 3.47 2.87 3.38 

Δ lot elevation (ft) 4.67 4.67 5.00 2.00 0.00 3.00 5.00 6.00 2.67 

1st floor (ft2

) 2,132 2,166 2,256 2,276 1,680 2,274 2,370 2,251 1,885 

Footing or fill pad ($) 6,332 5,966 3,243 0 3,663 0 4,162 4,137 4,771 

Forms or stem wall ($) 7,280 8,064 5,747 479 5,605 281 7,016 5,054 5,522 

Raised floor ($) 12,633 10,198 9,398 11,216 12,147 10,557 8,836 8,479 12,826 

Total floor and foundation ($) 26,245 24,228 18,388 11,696 21,414 10,838 20,014 17,670 23,119 

Perimeter footing (linear ft) 215 207 228 228 208 205 249 233 193 

Cost of foundation ($/ft2

) 31.71 30.82 27.86 30.24 38.66 27.95 23.17 26.42 35.37 

RSM footinga ($) 4,046 3,896 4,286 — 3,904 — 4,676 4,373 3,630 

RSM foundation walla ($) 6,084 5,778 4,851 2,842 4,072 2,850 6,350 4,915 4,804 

RSM 4-in. concrete slaba ($) — — 6,249 6,306 — 6,300 6,564 6,235 — 

RSM compacted filla ($) — — 5,969 3,530 — 3,932 7,522 5,914 — 

RSM wood decka ($) 13,133 13,341 — — 9,828 — — — 13,100 

RSM total cost estimate, unadjusteda ($) 23,263 23,016 21,355 12,678 17,803 13,082 25,111 21,437 21,534 

Builder over RSMa 1.13 1.05 0.86 0.92 1.20 0.83 0.80 0.82 1.07 a

Sources: Means (2010), Reed Construction Data (2011). 
Cost and Time Study for Constructing Raised Wood Floor Systems in the Gulf Coast Region of the United States

7

Time to Construct

Construction Critical Path Schedules

The builders in the study estimated the completion schedules for each of the foundation/floor systems in the study. 

We set a minimum of three calendar weeks for construction. 

However, failed inspection, inspection delay, weather, and 

other scheduling conflicts resulted in each of the foundation 

types being completed anywhere from five to nine calendar days more than estimated. Lots 11 and 18 were being 

built at the same time in locations less than one mile apart 

and were subjected to five days of weather delays. Table 5 

contains the estimated and actual construction schedules for 

representative raised wood, raised concrete, and concrete on 

pad foundation and floor systems.

Time

To aid in the cost comparisons in this study, the time to 

construct was compiled when feasible. Time was recorded 

at 5-min intervals for the duration of the work in progress. 

Appendix C contains the timesheets compiled on the lots 

observed.

Tables 6 and 7 excerpt some of the labor hours observed and 

contract costs for the three components of the foundation/

floor assembly of Lots 38 and 39. All of the labor hours recorded for Lot 38 were observed by researchers in the field. 

Only the labor hours specific to the wood floor assembly 

were observed for Lot 39. Thus, the labor hours attributed 

to the footing and foundation of Lot 39 were estimated as 

those observed for lot 38. The lots were next door to each 

other, built on the same topography with the same subcontractors for the same builder. Lot 38 was started in August 

2008 and Lot 39 was started in March 2009.

Comparing the two tables indicates that the contract cost 

for carpentry labor dropped approximately 37% on Lot 39, 

and the job was completed in 75% of the time. Based on the 

gross labor rate observed for Lot 38 (contract price divided 

by hours observed), the revised contract price might have 

been predicted. This is explored in the Value Engineering 

Strategies section. We saw a 25% improvement in time to 

construct, which may be attributed to the team honing its 

skill and approach as they learned the process.

Results

The cases used in this study indicate that the raised wood 

floor system and raised concrete slab on fill with stem wall 

foundations were comparable in construction critical path 

time. The raised wood systems cost an average of 32% more 

than the raised concrete on fill with stem wall (as measured 

by average cost of square foot of foundation wall). The 

difference in average elevation of the foundation walls supporting the two floor types was approximately 4 in. (wood 

measures 3 ft, 5 in. compared with concrete, which measures 3 ft, 1 in.).

Figure 6, a graph of the points collected in the study, represents cost per square foot of foundation wall and the average 

foundation height. The graph shows that the concrete raised 

slabs in the study cost less than the foundations with raised 

wood floors, which is supported by the comparisons in 

Table 4.

Trend lines developed from the plotted points are parallel, suggesting that the lines will not intersect (or costs will 

not be equal) at a higher foundation elevation. (The minimum code prescribed foundation height for a crawl space 

design is 2.5 ft, so the wood trend line’s upper end limit is 

Table 5—Construction schedules for lots in this study 

Days to complete 

Activity Estimated

Raised wood,

estimated 

Lot 38,

actual 

Raised

concrete,

estimated

Lot 11,

actual 

Concrete

on pad, 

estimated

Lot 18, 

actual 

Haul dirt for fill 1.5 0.0 0.0 1.5 1.0 1.5 1.5 

Compact fill 1.5 0.0 0.0 1.5 2.0 1.5 1.5 

Form slab 1.0 0.0 0.0 0.0 0.0 1.0 1.0 

Excavate/form footings 1.0 1.0 1.0 1.0 1.0 0.0 0.0 

Footing inspect 1.0 1.0 1.0 1.0 6.0 0.0 0.0 

Pour footings 1.0 1.0 1.0 1.0 0.0 0.0 0.0 

Lay block 4.0 4.0 7.0 4.0 8.0 0.0 0.0 

Grout block 1.0 1.0 2.0 1.0 3.0 0.0 0.0 

Rough plumbing 1.0 0.0 0.0 1.0 2.0 1.0 3.0 

Plumbing inspection 1.0 0.0 0.0 1.0 2.0 1.0 1.0 

Slab prep 1.0 0.0 0.0 1.0 1.0 1.0 9.0 

Slab inspection 1.0 0.0 0.0 1.0 1.0 1.0 1.0 

Slab pour 1.0 0.0 0.0 1.0 0.0 1.0 0.0 

Remove forms 1.0 0.0 0.0 0.0 0.0 1.0 3.0 

Install joists 3.5 3.5 8.0 0.0 0.0 0.0 0.0 

Install underlayment 1.5 1.5 1.0 0.0 0.0 0.0 0.0 

Jobsite idle, weekend — 4.0 Included 4.0 Included 2.0 Included 

Total calendar days 

to completion 

— 17.0 21.0 20.0 27.0 12.0 21.0 
Research Paper FPL–RP–664

8

that which is shown.) The trend lines indicate that cost per 

square foot of foundation declines as the elevation of the 

wall increases, or as the cost of the footing is spread across a 

larger area of foundation.

These costs represent two builders’ experience on several 

lots over a 2-year period of time.

Value Engineering Strategies

Competitive Bids

Carpentry costs per square foot for the four raised wood 

floors in the study varied from $3.00 (recorded in year one 

for Lots 38 and 39) to $1.48 (recorded in year two for Lots 

2W and 2J). The work spanned two years during which supply and demand conditions varied widely within the new 

residential construction market. However, the houses in the 

study are located within a 25-mile radius, so it is likely that 

they could have shared the same labor pool. Nationally, 

carpentry labor rates increased just less than 10% during the 

2-year study period—an oppositely directed trend from that 

observed during the present study. 

In the book Building Construction Cost Data (66th to 68th 

annual editions) published by Reed Construction Data for 

the years 2008–2010 indicates the following: the carpenter 

rate (per hour including fringes) for 2008 is $38.10, for 

2009 is $39.95, and for 2010 is $41.55. The percent delta 

is 9.06%. The delta is the ratio comparing the change in the 

price of the underlying asset to the corresponding change in 

the price of a derivative (Sometimes referred to as the hedge 

ratio). 

The carpentry crew at the low end of the range of cost per 

square foot of installed floor system added 72% additional 

cost per square foot to its established cost of $2.05 in order 

to frame the other components of the house (i.e., first- and 

second-floor interior and exterior walls, second floor, and 

conventionally framed steep-sloped hip roof). The added 

cost does not seem to be proportionate to the scope of the 

added work. (The observation relates to framing complexity 

of the entire structure as opposed to supporting time 

studies.)

Optimize Floor Systems

Each of the four raised wood floors in the study was designed with floor joists spaced at 16 in. on center and 23- to 

32-in. OSB floor underlayment. By increasing the floor 

framing spacing to 19.2 in. on center, less framing material could have been used while still providing a relatively 

stiff-feeling floor system. The conservative and more costly 

designs were used because designers and/or builders consistently were concerned with eliminating noticeable floor 

vibration and deflection. It is generally agreed that the code 

minimum deflection criteria for residential construction 

may not meet performance expectations (i.e., the feel) of 

modern-day buyers or the subsurface criteria for masonry 

floor finishes.

However, floor deflection can be given design consideration 

without strict adherence to a certain spacing and joist dimension. For example, the floor system of Lot 39 (Fig. 5) 

contained 2 by 10 joists of SYP #2 at 16 in. spacing with the 

greatest clear span of 11 ft, 0 in. (joist length of 12 ft, 4 in. 

with 8-in. CMU bearing each end). Consulting the Southern 

Pine Council’s (SPC) Maximum Spans Southern Pine Joists 

& Rafters, 2010 (SPC span tables, http://www.southernpine.

com/span-tables.asp) indicates that the first floor joists with 

the greatest clear span could have been specified with 2 by 

8 #2 SYP to meet design values of 50 lb/ft2 live load and 10 

lb/ft2 dead load with deflection of L/480; a deflection value 

33% stiffer than the minimum code criteria. Or, to meet deflection of L/600, 2 by 12s spaced at 24 in. on center could 

have been specified. Table 8 contains excerpts from the SPC 

10.00

20.00

30.00

40.00

0.00 1.00 2.00 3.00 4.00 5.00

Raised wood

on stem wall

Raised slab

on stem wall

Raised slab

on fill pad

Average foundationelevation above grade (ft)

Cost ($/ft2

)

Figure 6—Cost per square foot of foundation wall.

Table 6—Observed labor hours compared with 

contract cost for Lot 38 

Component Footing

CMU

walls

Wood

deck 

Aggregate assembly (h) 79.33 145.75 119.75

Labor contract cost ($) 1,850 2,344 6,396

Contract cost of labor (%) 17 22 60 

Gross hourly rate (observed time) 23.32 16.08 53.41

Table 7—Observed labor hours compared with 

contract cost for Lot 39 

Component Footinga

CMU

wallsa

Wood

deck

Aggregate assembly (h) 79.33 145.75 92.00

Labor contract cost ($) 1,855 3,197 4,007

Contract cost of labor (%) 20 35 44 

Gross hourly rate (observed time) 23.38 21.94 43.55

a

Hours estimated. 
Cost and Time Study for Constructing Raised Wood Floor Systems in the Gulf Coast Region of the United States

9

span tables with adjustment factors applied for higher deflection criteria. The L/480 and L/600 columns were created 

for this study from factors covered in the SPC span tables. 

Builders and designers may find it useful to have the tables 

with higher deflection criteria and higher live and dead loads 

at hand.

Alternatives highlighted in Table 8, such as changing the 

2 by 10 spacing to 24 in. on center or opting for even more 

stringent deflection and using 2 by 12s spaced at 24 in. 

might have reduced the total cost of the raised wood floor 

for Lot 39 by as much as $430, based on the spring 2009 

invoices rendered for the lot.

The 3-ply 2 by 12 floor girders installed in Lots 38 and 

39 met the design loads at a cost of $3.15 per linear foot, 

whereas the 2-ply 9 1/2 in. LVL girders in Lot 2W cost over 

three times that at $9.70 and the 3-ply at $14.55.

Continuous Versus Spot Footings

For two houses, Lots 38 and 39, continuous interior footings 

supporting piers required 13 cubic yards of concrete (Figs. 7 

and 8). The continuous footings were installed to eliminate 

differential settlement of the piers. Differential settlement 

of piers can be avoided by a continuous reinforced footing 

that may bridge a poor subsoil condition beneath a pier, as 

with this case. Differential settlement also can be avoided 

by sizing the footing and pier to sustain the calculated building load, removing all organic matter from the footing hole, 

and installing the footing below the frost depth. The amount 

of concrete required for interior footings could have been 

reduced by 8 cubic yards of concrete if spot footings 24 in. 

deep had been specified instead of the continuous footings. 

Individual footings might have saved $800 in the extant 

market during the summer of 2008.

Alternative Piers

Piers formed with sonotubes and filled when the block wall 

was grouted might have provided additional labor savings 

over CMU piers. Interior treated wood posts could have also 

provided labor savings compared with the CMU piers that 

were used.

Lower Piers to Allow In-Line Framing 

This option would design the piers at a lower elevation than 

the stem wall so that the girders can be dropped below the 

floor joists. Framing floor joists into the side of girders requires increased hardware and labor. Shorter pier height also 

adds to savings.

Reduce Interior Supports at Design Stage

Reduce the number of interior piers by using longer spanning floor joists. Eliminating piers, girders, and continuous 

footings would minimize costs.

Pier Spacing

When interior piers are supported with continuous footings, 

specify piers at close spacing so that dimensional lumber 

girders can be used.

Minimize Waste with a Bill of Materials and 

Cut List

The audited cases in this study consistently indicated that 

joist shipments did not match the estimates in length, quantity, or cost. Quoted prices were not honored despite delivery within the price hold period and supplier substitution of 

longer lengths was charged to the builder. As an example, 

Lot 2 (W, J), with a quantity and exact length floor joist 

layout incorporated into the architectural plans, received 

more than 100 linear feet of excess I-joist material at an additional cost greater than $300. Similar excess shipments of 

lumber were apparent in reviewing the invoices for each of 

the raised wood floors. To optimize the raised wood floor 

system’s affordability, builders and trade partners should 

address and solve this systemic inefficiency.

Table 8—Southern yellow pine (SYP) 

floor joist span tables 

SYP #2 better 

visually graded 

Deflection criteria L/360 L/480 L/600

Adjustment factors 1.00 0.91 0.84 

Span (ft) 

(inside to inside 

of bearings) 

Dimension

Spacing

(in.) 

40 lb/ft2

 live/ 

10 lb/ft2

 dead 

2 by 8 16.0 12.83 11.68a 10.78

2 by 8 19.2 12.08 10.99 10.15

2 by 8 24.0 11.00 10.01 9.24

2 by 10 12.0 18.00 16.38 15.12

2 by 10 16.0 16.08 14.63 13.51

2 by 10 19.2 14.67 13.35 12.32

2 by 10 24.0 13.08 11.90 10.99b

2 by 12 12.0 21.75 19.79 18.27

2 by 12 16.0 18.83 17.14 15.82

2 by 12 19.2 17.16 15.62 14.41

2 by 12 24.0 15.42 14.03 12.95c

50 lb/ft2 live/ 

10 lb/ft2

 dead 

2 by 8 16.0 11.92 10.85a 10.01

2 by 8 19.2 11.25 10.24 9.45

2 by 8 24.0 10.00 9.10 8.40

2 by 10 12.0 16.75 15.24 14.07

2 by 10 16.0 14.67 13.35 12.32

2 by 10 19.2 13.42 12.21 11.27

2 by 10 24.0 12.00 10.92b 10.08

2 by 12 12.0 19.83 18.05 16.66

2 by 12 16.0 17.16 15.62 14.41

2 by 12 19.2 15.67 14.26 13.16

2 by 12 24.0 14.00 12.74 11.76 c

a

Adequate design for Lot 39 1st floor joists at 16-in. 

spacing.

b

Alternate design for Lot 39 1st floor joists at 24-in. 

spacing.

c

Alternate design for Lot 39 1st floor joists at 24-in. 

spacing. Source: SPC (2010). 
Research Paper FPL–RP–664

10

Promote the Attributes of a Crawl Space

The four houses with crawl spaces in this study did not capitalize on the added space feature of the area below the first 

floor. Two of the crawl spaces had enough height to accommodate the same horizontal air handlers that were located in 

the attics of these houses. The crawl space summer temperature is usually close to the ambient temperature and at least 

–1 °C (30 °F) lower than the attic, which properly detailed, 

would provide a less harsh environment for the HVAC units 

and the ductwork and also increase energy efficiency. Installation of the MEP systems within the first floor assembly 

allows simple air and moisture sealing of the floor system to 

increase energy efficiency and indoor air quality.

One of the raised concrete slab with stem wall houses was 

built on a lakefront lot sloping down toward the water’s 

edge in the rear. Had that house been built with a crawl 

space the under floor area potentially could have provided 

easily-accessible storage for small boats and equipment 

(Fig. 9).

Optimized Case with Value 

Engineering Strategies

To explore whether these two types of foundations would be 

more cost competitive to build in some other case, specific 

costs (Table 9) were normalized and totaled in Table 10. The 

process of normalizing in this example set cost of concrete, 

CMU and footing labor cost, carpentry labor cost, and carpentry materials (dimensional lumber, 2 by 10 for Lots 38 

and 39, and 2 by 12 for Lots 2W and 2J) equal at the quantities used. Quantities for dimensional lumber were calculated 

Figure 7—Lot 39 foundation plan.

Figure 8—Lot 38 continuous interior footings and piers. Figure 9—Lot 11, rear elevation.
Cost and Time Study for Constructing Raised Wood Floor Systems in the Gulf Coast Region of the United States

11

to include several areas of lots 2W and 2J, with 2 by 12 on 

12 in. on center spacing to maintain stringent deflection 

criteria. Three-ply 2 by 12 beams replaced the 2-ply LVL 

in Lot 2W. The estimation detail for these is contained in 

Appendix D.

Figure 10, a graph of the optimized study cases with key 

costs set equal for all points, indicates that foundation costs 

per square foot can be lowered when the same market costs 

prevail. Including additional value engineering and material 

reductions could bring the raised wood and the raised concrete foundation costs closer together. 

Conclusion

Footings and foundations of the two types of raised floor 

systems could be constructed with equal costs, however, 

interior piers and crawl space foundation accessories add 

cost to the raised wood floor system. With specific layouts 

and quantities of dimensional lumber, the floor/foundation systems of the two types can approach equal cost. The 

optimized cost approach taken results in an average cost 

difference of $2.53 per square foot of foundation. Using the 

raised wood average foundation size of 704 ft2, the added 

cost of these components, which are unique to the raised 

wood foundation, would be $1,751.

References

Means, R.S. 2010. Residential Cost Data. Reed Construction Group. RS Means, Norwell, Massachusetts. http://www.

rsmeans.com/about/index.asp

Reed Construction Data. 2011 Norcross, GA. 

http://www.reedconstructiondata.com/

Southern Pine. 2011. Maximum Spans Southern Pine Joists 

and Rafters. Span Tables. http://www1.southernpine.com/

span-tables.asp

Southern Pine Council. 2010. Southern Pine Maximum 

Spans for Joists & Rafters. Kenner, Louisiana: Southern 

Pine Council. 35 p.

Waier, Phillip R.; Babbitt, Christopher; Baker, Ted; Balboni,

Barbara; Bastoni, Robert A.; Eds. 2010. RS Means Building 

Construction Cost Data. Robert S Means Co. 69 annual 

edition.

Table 10—Hypothetical case results

Foundation type

Raised

wood

Raised

concrete

Lot 38 Lot 39 Lot 2W Lot 2J Lot 22 Lot 11 Lot 34

Cost of foundation wall ($/ft2

) 25.45 27.71 31.93 31.42 27.67 22.99 26.65

Height (ft) 3.84 3.79 2.67 3.38 2.89 3.47 2.87

10.00

20.00

30.00

40.00

0.00 2.00 4.00

Raised wood

on stem wall

Raised concrete Linear

(raised wood)

Average foundationelevation above grade (ft)

Cost per ft2 of foundation ($)

Figure 10—Optimized cost per square foot of foundation 

wall with costs set equal.

Table 9—Costs used for 

hypothetical case

Cost

($) Unit

Concrete 76 Cubic yard

Footing labor 4 Linear foot

Carpentry 1.48 Finished ft

2

CMU labor 1.25 Block

2 by 12 beams 1.34 Linear foot
Research Paper FPL–RP–664

12

Appendix A. Relevant Indices

Appendix A—Relevant indices and costs 

Lot 38

Mobile,

AL

Lot 39

Mobile,

AL

Lot 22

Spanish

Fort,

AL

Lot 21

Spanish

Fort,

AL

Lot 2W

Daphne,

AL

Lot 18

Spanish

Fort, 

AL

Lot 11 

Spanish 

Fort, 

AL

Lot 34 

Spanish 

Fort, 

AL

Lot 2J

Montrose,

AL

Concrete, ($) per yd3, delivereda 96.47 99.19 74.00 72.00 72.00 74.35 76.32 — — 

Date foundation start 7/08 3/09 10/09 3/10 4/10 5/10 5/10 — — 

Footing labor, dig and pour (per ft) 5.00 5.00 4.00 4.00 4.00 — 4.00 — — 

CMU labor, per block (average) 2.00 1.85 1.54 — 1.25 — — — — 

Concrete labor, slab, per ft2 1.05 — 0.75 0.75 0.75 0.75 0.75 — — 

Concrete, per cubic yard, delivereda

 12.50 12.50 79.55 76.32 76.32 74.35 76.32 — — 

Carpentry labor, deck, per ft2

 3.00 1.85 — — 1.48 — — — — 

Rebar #4 1/2 in. 20 ft 7.89 — 6.50 — 6.35 — — — — 

Rebar #5 5/8 in. 20 ft 12.69 12.50 9.75 — 6.56 — 7.69 — — 

2 by 4 9 ft lodgepole — — — — — — 2.55 — — 

2 by 4 104 5/8 in. SPFb 4.21 — — — 3.21 — — — — 

2 by 4 18 ft lodgepole — 3.61 — — 5.64 — 5.22 — 4.96 

2 by 4 18 ft SPF 5.34 — — — — — — — — 

2 by 6 14 ft treated — — — — 10.36 — — — 6.85 

2 by 10 14 YPc — 9.35 — — 5.92 — — — — 

2 by 10 16 YP 10.66 12.96 — — — — — — — 

TJI 360 16 in. by 24 ft — — — — 73.78 — — — — 

2 by 12 14 ft #2 pine 13.83 — — — 14.74 — 14.74 — 9.43 

2 by 12 16 ft #2 SYP — — — — 21.07 — — — 13.47 

2 by 12 18 ft #2 SYP — — — — 24.77 — — — — 

4 by 8 23/32 in. or 3/4 in. OSB T&Gd

 21.53 20.08 — — 27.03 — — — — 

7/16 in. OSB 4 by 10 — — — — 17.66 — — — — 

7/16 in. OSB 4 by 8 — — — — 12.10 — 9.90 — — 

1 3/4 in. by 11 7/8 in. LVLe

 24 ft 115.52 — — — — — 157.93 — — 

a

Concrete price reported as the effective price; cost plus delivery/fuel surcharge plus sales tax, plus pump if applicable, divided by cubic 

yards delivered. All costs from invoices rendered at time of foundation construction including sales tax which ranged from 6%–9.5%, 

dependent on county. The current market for 2 by 12 is below $1/lin. ft (August 2010), verified by two suppliers, Lot 2J. b

Southern Pine flooring. 

c

Yellow pine. 

d

Oriented strandboard tounge and groove. 

e

Laminated veneer lumber. 
Cost and Time Study for Constructing Raised Wood Floor Systems in the Gulf Coast Region of the United States

13

Appendix B. Detail on Cost—Raised Wood
Research Paper FPL–RP–664

14

Appendix B. Detail on Cost—Raised Concrete with Stem Wall 

Foundation
Cost and Time Study for Constructing Raised Wood Floor Systems in the Gulf Coast Region of the United States

15

Appendix B. Detail on Cost—Raised Concrete on Compacted Fill Pad
Research Paper FPL–RP–664

16

Appendix C. Detail on Time to Construct
Cost and Time Study for Constructing Raised Wood Floor Systems in the Gulf Coast Region of the United States

17

Appendix D. Detail on Hypothetical Costs with Key Cost Components Set 

Equal

Appendix D—Costs used 

for hypothetical case

Cost

($) Unit

Concrete 76 Cubic yard

Footing labor 4 Linear foot

Carpentry 1.48 Finished ft

2

CMU labor 1.25 Block

2 by 12 beams 1.34 Linear foot
Research Paper FPL–RP–664

18