The inquiry
A distinctive bond pattern that demands precise detailing.
Florida Masonry received a request for information about stack bond brick walls used in brick veneer wall systems with stud wall backup and outboard mineral wool insulation.
The questionWhat guidance applies to stack bond brick walls used in a brick veneer system with stud wall backup and outboard mineral wool insulation?
The expert answer
Brick veneer that is not laid in running bond is not discussed in TMS 402/602, Building Code Requirements and Specification for Masonry Structures. The most applicable supporting information is available through the Brick Industry Association.
For installation, the Brick Industry Association recommends reinforcing the veneer with at least one wire embedded in the bed joints. This reinforcement is important because stack bond has no in-plane or out-of-plane structural value.
Use the correct anchor system
The veneer must also use the proper anchoring system for its backup construction. Wall ties are permitted only with wood stud backup. For steel stud or masonry backup, veneer anchors are required.
Control unit variation and alignment
Stack bond construction makes dimensional variation and alignment especially visible. Use brick with the least possible variation in unit size. The units should be aligned using the centerlines of the head joints.
For a modular-size FBX brick, ASTM C216 permits a variation in length of ± 5/32 inch. Variation in straight and plumb falls within the same parameters.
Put the requirements in writing
All reinforcement, anchoring, unit-selection, dimensional-tolerance, and alignment requirements should be clearly written into the project specifications. A mockup should also be required so appearance, alignment, and workmanship can be reviewed before the full veneer is installed.
Key takeaways
TMS 402/602 does not discuss brick veneer laid in a bond pattern other than running bond.
Stack bond veneer should include at least one reinforcing wire embedded in the bed joints.
Use wall ties only with wood stud backup; steel stud and masonry backup require veneer anchors.
Select brick with minimal unit-size variation and align units from the centerlines of the head joints.
Place dimensional and alignment requirements in the specifications and require a project mockup.
Florida Masonry Note
Stack bond brick veneer requires careful coordination among the designer, specifier, brick supplier, anchor-system provider, and mason contractor. Confirm that the specified reinforcement and anchorage are appropriate for the actual backup wall, and use the project mockup to establish the accepted standard of appearance and workmanship.