Masonry Magazine August 1980 Page. 16
The height limitations for brick veneer are based on the past history of successful performance. Empirical height limitations are provided in Table 1.
Supporting Brick Veneer
Brick veneer may be supported directly on either existing or new concrete foundations. Alternatively, it may be supported on steel angles anchored to existing concrete or masonry walls.
Foundations. The brickwork should extend down to the existing foundation where possible, as shown in Fig. la. If the existing foundation is not sufficiently wide to support the entire thickness of the brick wythe, a new foundation, as shown in Fig. 1b, can be installed at the same depth as the existing foundation. A bond break should be installed between the existing and new foundations to allow for any differential movement.
Steel Angles. An alternate method of supporting the brick veneer is shown in Fig. Ic. This requires attaching a continuous corrosion-resistant steel angle to the existing foundation or basement wall. The angle should be installed at or slightly below grade. Installing the angle below the frost line will decrease the possibility of deleterious effects resulting from freeze-thaw actions. The angles should be attached to existing basement or foundation walls constructed of concrete or masonry. Angles should never be anchored to wood plates or framing members.
This method of support should be used with caution. A careful analysis of the loads being applied to the angle should be made. Special consideration should be given to the eccentricities of the applied loads. The sizing and spacing of bolts must be carefully computed, taking into account not only the loads to be carried, and their resulting eccentricities, but also the strength of the foundation wall itself. In general, this method of support should be confined to one-story structures where the total height to the plate does not exceed approximately 14 ft (4.3 m).
Attachment
The brick veneer must be securely attached to the existing construction. Provide one tie for each 25 sq ft (0.24 m²) of wall area. The maximum spacing of ties, either horizontally or vertically, should not exceed 24 in. (600 mm) o.c. This tie spacing applies above and below grade. The above-grade spacing may be reduced to one tie for each 34 sq ft (0.30 m²) of wall area for one and two-family dwellings not exceeding one story in height.
Flashing and Weepholes
Good flashing details, similar to those shown in Figs. Ic, 2, and 3 are essential to brick veneer construction. In order to divert the moisture out of the air space through the weepholes, continuous flashing should be installed at the bottom of the air space. The flashing must be at or above grade. Where the veneer continues