Commercial Building Inspector B2Wall Construction and Wall CoveringsMedium
An inspector observes a newly installed exterior wall covering on a commercial building. The covering consists of a masonry veneer with an air space. What is the minimum required clear air space between the masonry veneer and the sheathing, assuming no other specific drainage or ventilation requirements are stated?
- A1/4 inch
- B3/8 inch
- C1 inch
- D1/2 inch
Show answer & explanationAnswer & explanation
Correct answer: C. 1 inch
According to IBC Section 1405.10.4, a minimum 1-inch clear air space is required between the masonry veneer and the sheathing to allow for proper drainage and ventilation, unless a different method is approved.
Why the other options are wrong
- A. 1/4 inch is generally insufficient for a clear air space with masonry veneer.
- B. 3/8 inch is too small to provide adequate drainage and ventilation for masonry veneer.
- D. 1/2 inch is not the minimum specified by the code for this application.
Masonry Veneer Air Space
A clear air space is required behind masonry veneer to prevent moisture accumulation, allow for drainage, and promote drying of the wall assembly.
- Prevents moisture from penetrating the building envelope.
- Allows drainage of incidental water.
- Promotes ventilation and drying of the wall cavity.
- Typically 1 inch minimum per IBC 1405.10.4.
Memory trick: Veneer's Vent: Vital for Water's Vanish.