I have designed a brick veneer/steel stud wall using Brick Institute of America (BIA) recommendations. I'd now like to switch from clay brick to concrete brick. May I use the BIA recommendations to design the concrete brick veneer wall?
Although the two wall systems should perform similarly, BIA recommendations do not address concrete brick. For concrete masonry veneers, consult NCMA-TEK 114A, "Structural Backup Systems for Concrete Masonry Veneers," published by the National Concrete Masonry Association (NCMA). NCMA recommendations differ substantially from those of BIA. BIA recommends designing steel stud backup walls to handle 100% of the lateral loads without deflecting more than 1/600 of the span. According to NCMA, if the veneer and backup are adequately tied together, they will deflect equally under load and the lateral load will be distributed to each wythe in proportion to its relative stiffness. NCMA therefore recommends that the veneer and backup be designed so that allowable stresses are not exceeded, thus preventing flexural cracking. The distribution of loading between the veneer and backup should be based on their relative stiffness. This accounts for the difference in the size and spacing of the backup required by the two systems. Concrete brick generally require heavier steel studs and closer stud spacings than do clay brick.