Masonry Magazine June 1980 Page. 19
Ties for Wood Frame Backup
Corrosion-resistant corrugated metal ties, at least 22 gage, % in. (22 mm) wide, 6 in. (150 mm) long, as shown in Fig. 2a, are used to attach brick veneer to wood frame backup. The ties are usually fastened to the wood frame with corrosion-resistant nails that penetrate the sheathing and are driven a minimum of 1/2 in. (40 mm) into the studs.
Ties for Metal Stud Backup
Corrosion-resistant wire ties, at least 9 gage, should be used to attach brick veneer to metal studs. Typical wire ties, as shown in Figs. 2b and 2c, may be used to attach brick veneer to metal studs. Wire ties with a minimum diameter of 3/16 in. (4.8 mm), as shown in Fig. 2d, may be used to attach brick veneer to structural steel. A suggested method of securely attaching the ties to the steel frame is shown in Fig. 3.
Ties for Masonry Backup
Rectangular ties, U ties or Z ties are used to attach brick veneer to masonry backup systems as shown in Figs. 2g and 2h. Z ties should not be used in conjunction with hollow units. The use of continuous horizontal joint reinforcement with tab ties is recommended for use with concrete masonry backup. All ties should be of at least 9 gage corrosion-resistant wire. In most instances, it is recommended that brick veneer with masonry backup systems be designed as cavity walls, see Technical Notes 21 Series.
Ties for Concrete Backup
Where brick veneer is attached to concrete, corrosion-resistant wire or flat bar dovetail anchors are recommended. Wire anchors should be at least 6 gage and 4 in. (100 mm) wide with the wire looped and closed. Flat bar dovetail anchors should be at least 16 gage with a minimum width of % in. (22 mm). Flat bar dovetail anchors should be fabricated so that the end embedded in masonry is turned up 14 in. (6 mm). Dovetail anchors should be embedded at least 2 in. (50 mm) into the bed joint of the veneer, and anchored to dovetail slots placed in the concrete. Dovetail anchors are shown in Figs. 2e and 2f. One method for the attachment of brick veneer to a concrete structural member is shown in Fig. 3.
Flashing and Weepholes
There are many types of flashing available which are suitable for use in brick veneer walls. Sheet metals, bituminous membranes, plastics, or combinations of these have been used successfully. Acceptable bituminous membranes do not include asphalt impregnated felt. Selection of flashing is often determined by cost; however, it is recommended that only superior materials be used, because replacement in the event of failure is exceedingly expensive, if not impossible.
Weepholes can be formed by omitting mortar from all or part of the head joint when constructing the veneer. They may also be formed by using a removable forming material, such as a well-oiled rod, which will leave an unobstructed opening; or plastic tubing, rope wicks, or other materials which are left in place. For further discussion on flashing and weepholes see Technical Notes 7A, "Flashing Clay Masonry".
Movement Provisions
Design provisions for movement which include bond breaks, expansion joints, and joint reinforcement, are not usually required in residential and low-rise brick veneer construction. However, they may be required in specific situations.
Bond Breaks
Through-the-wall flashing at the base of the wall between the veneer and the foundation will provide sufficient bond break. Additional information on bond breaks is provided in Technical Notes 18 Series and 21B.