Canadian Consulting Engineer


Rain Check

Moisture is drained toward the bottom of the wall within the cavity, where it is intercepted by the flashing over the shelf angle. From there the moisture is directed to the exterior through weep holes. A sheet metal flashing extends beyond the exterior face of the brick veneer, forming a drip edge for water to be shed away from the brick face. Insulation is located on the outside face of the block to maintain continuity and minimize heat loss at the slab edge. Only the supports for the shelf angle interrupt the insulation. Weep holes are spaced a maximum of 600 mm on centre for better draining and venting for pressure equalization (Building codes recommend spacing of 800 mm on centre). Weep holes must be free of mortar droppings. A compressible joint is required at the top of the brick veneer and non-load-bearing concrete block at the underside of the bent steel plate and concrete slab to allow for deflection, frame shortening and volume changes in the brick and block.From CMHC Best Practice Guide, Brick Veneer Concrete Masonry Unit Backing by Ashok Malhotra, P.Eng., Halsall Associates.