The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California

First Aid For The Ailing Houses

There may be leakage through the face of a wall. With a brick wall, leakage is usually through the mortar joints. Bricks will absorb moisture, but when they are soaked, the water will not pass through. With all of the joints throughout a wall solidly filled with mortar, leakage is not likely. In low-cost and hurried construction, joints inside a wall may not be completely filled. When straight portland-cement mortar is used, hairline cracks may form between the upper edge of a mortar joint and the under side of a brick through which water will pass by capillary attraction or by being driven by a wind. Entering the unfilled spaces inside the wall, this water will pass through.

A brick wall can be made watertight with a sealing coat made of equal parts of spar varnish, red-lead paint, and turpentine. In preparation for this, crumbling mortar joints should be repointed, and all cracks, breaks, and holes filled with caulking compound. The sealing coat should be applied liberally at a time when the brickwork is thoroughly dry, and allowed to soak in. When dry, it can be finished with any good house paint. Transparent liquid waterproofing is also widely available.

A remedy for leakage through defective mortar joints is to rake the mortar from the outside joints to a depth of 1/2 inch or more, and to fill with a mortar that will not permit water to enter. A good mixture for this purpose is 1 part Portland cement, 1 part hydrated lime, 5 parts sand.

Excellent prepared mortar may be purchased at paint or building-supply dealers. It is supplied in dry form in small bags, and as much as needed may be mixed with water to form a thick paste.

Hairline cracks can be closed with a colorless waterproofing liquid, of which there are a number on the market. These are best applied by a concern in the business, with apparatus to force the liquid into the masonry. Under such conditions, the wall should be waterproof for a number of years.

Waterproofing is often necessary when efflorescence is abundantly evident (see section on Efflorescence). This white deposit on the surface of masonry (particularly brick) is caused by moisture penetrating the wall, then evaporating, bringing the alkali in the masonry to the surface. Efflorescence will eventually cease when all of the alkali is leached from the wall. But it is just a symptom of the disease—moisture entering the walls.

Excellent waterproofing compounds are available in paint stores. Some of these combine the waterproofing qualities of silicones with a wax- or oil-base liquid. These waterproofing compounds darken the surface of the brick or other masonry somewhat, but do not obscure the texture or basic color of the wall. Another type of waterproofing compound is a paint. This formulation embodies special waterproofing materials in an oil- or water-emulsion paint. Where concrete is to be protected, this type is most useful. Most such compounds may be simply applied with a brush, roller, or spray, but manufacturer's directions should be followed.