Masonry Magazine June 1980 Page. 17
BIA Technical Notes
on Brick Construction
Brick Institute of America 1750 Old Meadow Road, McLean, Virginia 22102
INTRODUCTION
BRICK VENEER
NEW CONSTRUCTION
Brick veneer construction consists of a nominal 3-in. (75 mm) or 4-in. (100 mm) thick exterior brick wythe, tied to a backup system with metal ties in such a way that a 1-in. (25 mm) clear space is provided between the veneer and the backup system. The backup system may be wood frame, metal stud, or masonry. The brick veneer is supported on the foundation and is designed to carry no vertical loads, other than its own weight.
Until recently, brick veneer construction was limited principally to houses. It is now being used on low-rise construction and is often being considered for high-rise buildings. The application of brick veneer in high-rise construction is discussed in Technical Notes 28B. This Technical Notes deals with the empirical design of brick veneer in buildings limited to 3 stories in height. The height limitations shown in Table 1 are based on successful past performance of brick veneer and various backup systems.
There are six requirements for satisfactory performance of brick veneer: (1) an adequate foundation, (2) a sufficiently strong, rigid, well-braced backup system, (3) proper attachment of the veneer to the backup system, (4) proper detailing, (5) the use of proper materials, and (6) good workmanship in construction.
PROPERTIES OF BRICK VENEER
# Strength
Factors that affect the strength of brick veneer are the height of the brick veneer, the stiffness of the backup, and the tie system. In addition to its own weight, the only load that the brick veneer should carry is a proportionate share of the lateral load. Due to the relatively low stiffnesses normally achieved in wood frame and metal stud backup systems, the brick veneer usually carries the majority of any lateral load. This occurs even though brick veneer is not usually designed to carry lateral loads.
Fire Resistance
Typical brick veneer wall assemblies have fire ratings of up to 2 hr. Figure 1 shows a typical brick veneer wall assembly with a 2-hr fire rating.
Moisture Resistance
Brick veneer wall assemblies are drainage type walls. Walls of this type, which include cavity walls, are recommended where maximum resistance to rain penetration is desired. It is essential to maintain the 1-in. (25 mm) clear space between the brick veneer and the backup to ensure proper drainage. Refer to Technical Notes 7B, "Moisture Control in Brick and Tile Walls-Rain Penetration", for more information.
Resistance to Heat Transmission
Brick veneer wall assemblies provide both resistance to the transmission of heat and capacity insulation. The overall coefficient of heat transmission, U, of these
TABLE 1
Empirical Height Limitations for Brick Veneer
| Nominal Thickness of the Brick Veneer, in (mm) | Stories | Height at Plate ft (m) | Height at Gable, ft (m) |
| - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -