Masonry refers to construction using “units” of clay bricks, concrete bricks, natural stone, or one of the many types of manufactured stone units available on the market. Exterior masonry veneer is constructed from these units by laying each into a mortar bed, and anchoring it with metal ties to the wood frame of the home.

Masonry limits the inward movement of moisture. Air space located behind the masonry prevents absorption of moisture inward and allows air circulation for drying. Any moisture that does pass through the veneer drains downward in the air space to the wall base where it is redirected back to the exterior.

You may notice empty vertical masonry joints that do not contain mortar between adjacent bricks or stone units along the bottom row of masonry at the wall base. These are “weep holes” which are intentionally placed during the construction of the masonry. They allow drainage of moisture from behind the masonry veneer back to the exterior, and air circulation in the air space for drying. Do not fill or block these empty joints.

General Maintenance

Seasonal care and maintenance of exterior masonry components, include:

  • Do not allow snow to accumulate against masonry surfaces;
  • Do not direct sprinklers (including automatic sprinkler systems) towards masonry walls;
  • Do not cover masonry weep holes with built-up flower beds;
  • Do not use de-icing salts on horizontal surfaces (i.e., sidewalks and driveways) near masonry;

Hairline cracks between bricks or stones and mortar are common and have little effect on the wallʼs ability to manage water – they are not usually a concern. However, loose bricks or stones and missing mortar should be replaced.

Efflorescence on Masonry (Salt Deposits)

Efflorescence is a mineral salt deposit (usually white in colour) that may develop on the surface of masonry. All masonry materials are susceptible to efflorescence. As water moves through the body of masonry materials, it will dissolve any available mineral salts. As the moisture evaporates at the surface, it will deposit these salts. The degree of efflorescence varies depending on the age of the finished surface, the type and colour of the cement materials, weather condition, and the availability of water and salt sources.

Did you Know?

A wood-framed two-story home can shrink vertically adding substantial forces on virtually any rigid building component in the home, including drywall (also known as gypsum wallboard). A minor drywall crack can easily be remedied with tap, mud and primer when a room is being repainted.

There are several potential sources of mineral salts, including:

  • Naturally present salts in cement-based construction materials that are not yet bonded by chemical reaction with the cement particles;
  • The water used to mix cement-based materials (i.e., well-water can also contain high concentrations of salt whereas tap water is usually low in dissolved salts);
  • De-icing salts used on horizontal surfaces (sidewalks and driveways) where masonry is in close contact – de-icing salts provide a source of salt and melting snow and ice provide a source of moisture that can result in efflorescence on masonry;
  • Soil used in planting beds provides a continuous supply of moisture and salts that can be absorbed by masonry.

Efflorescence is usually temporary because the salt source is very limited. Generally speaking, efflorescence will usually occur only during the first year or two after construction. It tends to lessen with the passage of time as the materials “purge” themselves of salts unless an alternate salt source such as soil or de-icing salts is present.