Brick is durable, beautiful, and often increases the resale value of homes. Under normal weather conditions and with the proper maintenance, bricks can last for a century or more. With the proper attention, brick is not difficult to maintain. However, they are vulnerable to moisture, and can degrade, or “spall,” over time, especially when subject to freezing/thawing cycles.
Periodically check over your brick home. Check the interior walls for any sign of moisture or damage. When inspecting the exterior walls, it is important to look for:
Plant Growth – Cut plants, such as ivy, as close to the surface as possible. Do not pull.
Weep Holes – These small holes at the bottom of the brickwork allow moisture to drain out of the wall. Clean them out if they are plugged.
Efflorescence – A white, salty deposit on the brick surface is a sign of water penetration. You can clean this with a stiff brush, or a brush with water. If hard deposits have formed, a chemical cleaner is needed. Do not power wash.
Mortar – Mortar is less durable than brick, and can be maintained by “repointing.” To repoint, chip the old mortar out to a depth of ½-inch to ¾-inch. Then dampen the joints with water, and repack with new mortar. Wipe off the excess with a damp cloth. Repointing is normally recommended every 25 years, but every 50 years isn’t usually too long in mild climates.
Damaged Bricks – To replace a brick, remove the mortar around it to a depth of 4 inches. Dislodge the brick, and clean the cavity. Next, dampen the cavity with a touch of water, spread mortar onto the bottom of the cavity, and replace the brick. You can also temporarily repair the brick by carefully spreading a sandy cement mixture, “render,” over its surface.
Selecting Bricks and Mortar
When repairing a wall, choose bricks and mortar that are similar to the existing products. The age and location of the building can be used to determine the appropriate products. When selecting bricks and mortar, climate and function are also important. It is important to check the ASTM Standards, in particular ASTM C216, “Standard Specification for Selecting Brick,” and ASTM C270-04, “Standard Specification for Mortar for Unit Masonry,” for appropriate recommendations.
Use a Sealant?
Although there is a great deal of debate on the subject, some experts recommend using a chemical coating or sealant to prevent water from penetrating the brick. There are two main types of sealants:
Films – Films cover the surface of the brick, repelling water and usually preventing markings like graffiti from sticking. They tend to leave a glossy or darkened appearance. While they keep water out, they also keep water in, not allowing the brick to breathe. Only use when brickwork is dry. If moisture is trapped in the brick and a freeze/thaw cycle occurs, spalling will result.
Penetrants – Penetrants penetrate the surface and coat the brick pores, making them water repellent. Penetrants are translucent, and allow the brick to breathe. As a result, they would be beneficial in cold, moist climates, or on chimneys and parapets where they are exposed to harsh conditions.
Films and penetrants cost about 10 cents per square foot. Depending on the product, films need to be reapplied at least every five years, while sealants can last up to 15 years.
New Types of Masonry
Autoclaved Aerated Concrete A precast, non-organic, non-toxic and airtight lightweight building stone. It has good acoustic and thermal insulative properties.
Mortarless Brick Veneer Concrete bricks cast in special shapes that can be installed by anyone, and without the use of mortar.
Split-Face Concrete Block Architectural concrete masonry units that have a rough, stone-like texture that do not require a decorative finish.
Additional Sources of Information:
The Brick Industry Association provides a great deal of technical information and can provide you with technical assistance.
The Masonry Society is a professional, technical, and educational association dedicated to the advancement of knowledge on masonry.