Leak Through a Brick Wall

Removing the Brick

• You cannot remove the brick in one piece, so begin by scoring the side of the brick with a masonry-cutting disk attached to a power drill. Score the brick horizontally and along the entire length of the brick. Also score the mortar joints surrounding the brick. Scoring the brick and the mortar joints will make breaking the brick apart much easier. Break the brick apart along the score lines with a masonry chisel and hammer. With the brick removed, chisel away the surrounding mortar joints, taking care not to damage the surrounding bricks.

Preparing the Surface and the Mortar Mix

• Properly preparing the surface of the wall is perhaps the most important part of the repair process as it will ensure that the new mortar properly seals against the surrounding surfaces to prevent leaks. Remove as much of the old mortar and dust as reasonably possible with a wire brush, then rinse the area down with water and allow it to dry completely. Aside from mortar, you will also need a concrete fortifier, which is a liquid product that strengthens the mortar and helps guard against water leaks. An optional product is a concrete pigment. The pigment is also a liquid product and is mixed with the mortar and fortifier to darken the mortar, which will allow the new mortar to blend in with the surrounding mortar in the wall. Follow each product’s instructions carefully when preparing the mix.

Installing the Brick

• Two applications of mortar are necessary. The first application is made within the cavity of the wall. Spread a 1-inch thick layer of the mortar mixture across the bottom and against the sides of the cavity with a pointing trowel. Dampen the brick slightly with water, then spread the second application of mortar across the sides and against the top of the brick. As with the first application, the second application of mortar should also be approximately 1-inch deep. Don’t worry about using too much mortar as the excess will be scraped away. Position the brick against the wall cavity, and tap the brick into the wall with the handle of the trowel until the new brick is flush with the surrounding bricks. Scrape the excess mortar away from the wall with the trowel. To create a smooth surface in the mortar joints, drag a jointing tool across the mortar before it dries.

Taking Preventative Measures

• Fixing the leak in the wall may only be a temporary repair unless the underlying problem is resolved. If the wall is very old and the mortar is deteriorating, you may want to eventually replace the wall. Older brick walls, or brick walls with deteriorating mortar, sometimes experience a condition called spalling, which occurs when water penetrates the wall and then freezes. The frozen water expands and can crack the bricks and mortar joints. If you suspect that the leak was caused by a runoff problem, regard the surrounding landscape to direct water away from the wall. Also check any rain gutters that are close to the wall for clogs.