Brick is a handsome, durable and nearly trouble free exterior for both residential and commercial construction. But to properly maintain the appearance and durability of a masonry facade it is essential that it be properly constructed and periodically maintained.
Weather, meaning rain, moisture and or Minnesota freeze and thaw cycle, is the enemy of masonry. If given the opportunity, wind driven moisture will seep its way into the thinnest crack, freeze, then spal off a tiny piece of mortar. Leaving a slightly bigger crack for the next cycle. Over time, without proper maintenance, this spalling cycle can lead to disintegrating mortar, cracked and loose brick, and interior water leaks. A white powdery substance on the wall exterior called efflorescence, which is a fine salt like substance is often evidence of moisture within the wall. These interior water leaks can cause mold and mildew. They could eventually rust out the connections holding the brick facade to the building structure, which could allow the wall to bow out and may result in a collapse of part of the building facade.
A properly constructed masonry wall consists of wicks and weep holes to allow any condensation that collects inside the wall to drain out. The mortar joints are tooled to allow rain to run off, rather than collect on ledges or rough edges. Sills are properly sloped and caulked and overhang the wall to allow water to drip free of rather than run down the face of the wall. Wall caps must also overhang the wall and include a drip break to allow water to drip clear from the face of the wall. It is especially important that any joints in the wall cap are properly caulked because a leak here will allow moisture into the brick or between the brick facade and the structural wall.
Over time, all exterior masonry walls will need repair to restore the mortar to near original condition with a process called tuckpointing. Tuckpointing consists of the raking, grinding or fine sandblasting of the joints to remove all loose and powdery mortar. If the mortar is cracked, it is chiseled out so the new mortar will have a more solid base to bond to. The old mortar is then moistened to aid in adhesion and control shrinkage, and then new mortar is applied to the joints and tooled to match the original joint. Particular attention must be given to the wall caps. The mortar between the clay tile caps used on older commercial buildings and residential chimneys is very likely bad and allowing water to leak into the wall. These caps should be replaced with a new stone or metal cap flashing.
With proper maintenance, some exterior masonry facades have lasted for well over one hundred years.
