Attachment of Brick Veneer in High-Wind Regions

Hurricane Katrina Recovery Advisory
FEMA
December 2005

Purpose: To recommend practices for installing brick veneer that will enhance 
wind resistance in high-wind areas.

Key Issues

Brick veneer is frequently blown off walls of residential and commercial 
buildings (Figure 1). When brick veneer fails, wind-driven water can enter and 
damage buildings, and building occupants can be vulnerable to injury from 
windborne debris (particularly if walls are sheathed with plastic foam 
insulation or wood fiberboard in lieu of wood panels). Pedestrians in the 
vicinity of damaged walls can also be vulnerable to injury from falling veneer 
(Figure 2).

Figure 1. Failed brick veneer. Plastic foam wall sheathing was installed over 
the wood studs (plywood was temporarily installed after the brick failure).

Figure 2. The upper portion of the brick veneer at this apartment building 
collapsed. Pedestrian and vehicular traffic in the vicinity of the damaged wall 
were vulnerable to injury and damage if remaining portions of the wall were to 
collapse during subsequent storms.
 
Common failure modes include tie (anchor) fastener pull-out (Figure 3), failure 
of masons to embed ties into the mortar (Figure 4), poor bonding between ties 
and mortar and mortar of poor quality (Figure 5), and tie corrosion (Figure 6).

Figure 3. This tie remained embedded in the mortar joint while the smooth-shank 
nail pulled from the stud.

Figure 4. These four ties were never embedded into the mortar joint.

Figure 5. This tie was embedded in the mortar, but the bond was poor.

Figure 6. There were several ties in this portion of the wall, but they failed 
due to severe corrosion.
 
Ties are often installed before brick laying begins. When this is done, ties 
are often improperly placed above or below the mortar joints. When misaligned, 
the ties must be angled up or down in order for the ties to be embedded into the 
mortar joints (Figure 7). Misalignment not only reduces embedment depth but also 
reduces the effectiveness of the ties because wind forces do not act parallel to 
the ties themselves.

Figure 7. Misalignment of the tie reduces the embedment and promotes veneer 
failure.

Corrugated ties typically used in residential veneer construction provide 
little resistance to compressive loads. Use of compression struts would likely 
be beneficial, but off-the-shelf devices do not currently exist. Two-piece 
adjustable ties (Figure 8) provide significantly greater compressive strength 
than corrugated ties.

Figure 8. Examples of two-piece adjustable ties, one showing base and vee anchor 
and the other showing eye and pintle anchor 

Many buildings that exhibited damaged veneer were not in compliance with 
current building codes. Building code requirements for brick veneer have changed 
over the years. Model codes prior to 1995 permitted brick veneer in any 
location, with no wind speed restrictions. Wall area per tie in some model codes 
was greater than the current maximum. The current masonry code referenced in 
model building codes, Building Code Requirements for Masonry Structures, ACI 
530/ASCE 5/TMS 402 (ACI 530) addresses brick veneer in two manners: rational 
design and prescriptive requirements. Essentially all brick veneer in 
residential and low-rise construction follows the prescriptive requirements. The 
first edition of American Concrete Institutes (ACIs) 530 limited the use of 
prescriptive design to areas with a basic wind speed of 110 mph or less. The 
2005 edition of ACI 530 extended the prescriptive requirements to include a 
basic wind speed of 130 mph, with lower area per tie limits. In locations with a 
basic wind speed above 130 mph, the rational design approach must be used. 
Compliance with ACI 530-05 should reduce wind damage.

The following Brick Industry Association (BIA) Technical Notes provide guidance 
on brick veneer: Technical Notes 28  Anchored Brick Veneer, Wood Frame 
Construction, Technical Notes 28B  Brick Veneer/Steel Stud Walls, and Technical 
Notes 44B  Wall Ties (available online at www.bia.org). These Technical Notes 
provide attachment recommendations, but the recommendations are not specific for 
high-wind regions and are, therefore, inadequate.

Construction Guidance

The brick veneer wall system is complex in its behavior. There are limited test 
data on which to draw. The following guidance is based on professional judgment, 
wind loads specified in ASCE 7-02 Design Loads for Buildings and Other 
Structures, fastener strengths specified in the American Forest and Paper 
Associations (AF&PAs) National Design Specification for Wood Construction, and 
brick veneer standards contained in ACI 530-05. In addition to the general 
guidance given in BIA Technical Notes 28 and 28B, the following are recommended:

Note: In areas that are also susceptible to high seismic loads, brick veneer 
should be evaluated by an engineer to ensure it can resist seismic and wind 
design loads.

Stud Spacing: For new construction, space studs 16" on center, so that ties can 
be anchored at this spacing.

Tie Fasteners: Ring-shank nails are recommended in lieu of smooth-shank nails. A 
minimum embedment of 2" is suggested. 

Ties: For use with wood studs: two-piece adjustable ties are recommended. 
However, where corrugated steel ties are used, use 22-gauge minimum, 7/8" wide 
by 6" long, complying with ASTM A 366 with a zinc coating complying with ASTM A 
153 Class B2. For ties for use with steel studs, see BIA Technical Notes 28B  
Brick Veneer/Steel Stud Walls. Stainless steel ties should be used in areas 
within 3,000 feet of the coast.

Tie Installation
 
Install ties as the brick is laid so that the ties are properly aligned with 
the mortar joints.
 
Install brick ties spaced per Table 1. Studs should be installed at 16" 
spacing. Veneer tie locations for 24" stud spacing are included for repairing 
damaged veneer on existing buildings with the wider stud spacing.

Locate ties within 8" of door and window openings and within 12" of the top of 
veneer sections.

Bend the ties at a 90-degree angle at the nail head in order to minimize tie 
flexing when the ties are loaded in tension or compression (Figure 9).

Figure 9. Bend ties at nail heads 

Embed ties in joints so that mortar completely encapsulates the ties. Embed a 
minimum of 1.5" into the bed joint, with a minimum mortar cover of 5/8" to the 
outside face of the wall (Figure 10). 

Figure 10. Tie embedment 

[Begin table]
Table 1. Brick Veneer Tie Spacing

Wind Speed (mph)(3-Second Peak Gust)	Maximum Vertical Spacing for Ties
							16" stud spacing	24" stud spacing
 90							18.0a  		16.0a
100							18.0a			16.0a
110							18.0a			14.8
120							18.0a	  		NAb
130							15.9	  		NAb
140							13.7	  		NAb
150							10.2	  		Nab

Wind Pressure (psf) 				Maximum Vertical Spacing for Ties
							16" stud spacing	24" stud spacing
17.8							18.0a  		16.0 a
22.0							18.0a			16.0 a
26.6							18.0a			14.8
31.6							18.0a	  		NA b
37.1							15.9	  		NA b
43.0							13.7	  		NA b
49.4							10.2	  		Na b			

Notes:
1. The tie spacing is based on wind loads derived from Method 1 of ASCE 7-02, 
for the corner area of buildings up to 30' high, located in Exposure B with an 
importance factor (I) of 1.0 and no topographic influence. For other heights, 
exposure, or importance factor, an engineered design is recommended.
2. Fastener strength is for wall framing with a Specific Gravity G=0.55 with 
moisture contents less than 19% and the following adjustment factors, Ct=0.8; 
and CD, CM, Ceg, and Ctn=1.0.
3. Nail embedment depth of 2" for 2.5" long 8d common (0.131" diameter) ring-
shank fasteners 
a Maximum spacing allowed by ACI 530-05
b 24" stud spacing exceeds the maximum horizontal tie spacing of ACI 530-05 
prescribed for wind speeds over 100 mph
[End table]