From stately colonials to simple ranches, brick has remained as a popular building material for centuries. Its energy efficiency and aesthetic appeal are an added bonus in terms of resale value. Brick is relatively maintenance free, but occasional cleaning, spot checks for water damage, and repointing are necessary in order to ensure long-lasting structural integrity.
The least aggressive approach should be your first plan of action when it comes to cleaning brick. Just like soiled clothing, different types of dirt on your home's exterior will require a different cleaning agent. Once a year use a garden hose, with a spray nozzle, or a spray bottle to remove any loose dirt.
If a particular side of your home receives little to no sunlight and the nearby vegetation is damp, be on the lookout for moss, mold, or mildew growth. A solution of one cup of bleach mixed with a gallon of water can be applied with a scrub brush can be used to clean most problem areas. Use a natural or synthetic bristle brush - wire brushes leave traces of steel behind that will rust and discolor the bricks. Before applying a bleach solution to brick, give the area a thorough soaking. This will help prevent the brick from absorbing the bleach.
Avoiding Water Damage
Water damage is caused by one of two conditions: splash back or rising damp. In splash back, the continually of rain beating against the brick soaks into the mortar, causing the mortar joints or the bricks to crack. Rising damp results when ground water seeps up from below, leaving behind what is called a tide line. The moisture above the tide line will eventually evaporate, but the salt crystals that remain will, over time, cause the bricks and mortar to break down. Freezing and thawing cycles can accelerate damage to water-soaked brick, so repairing problems early will prevent more extensive repairs in the future. Look for water damage on an annual basis, and budget for some possible repointing every five to ten years.
Repointing is necessary in places where the mortar joints have become soft or the mortar itself is cracked or damaged. The damaged mortar is removed carefully so as not to disturb the surrounding brickwork. Fresh mortar is applied in layers. When repointing, the depth of the new mortar should be twice the width of the mortar joint. Mortar applied directly to the damaged surface will not hold up.
Owners of historic or older homes will want to make sure that the fresh mortar matches the original. A contractor will take a sample of the mortar, crush it, and dissolve it in acid. This process removes the binder and leaves behind the sand aggregate, making it easier to identify the proper shade.
Painting a brick facade was first in vogue in the early 1800's. Removing that paint can be a painstaking process. Chemical treatments work best for paint removal, and are best left to professionals. Sandblasting should never be the remedy for paint removal, as it causes lasting damage to the beauty and integrity of brick. The remaining brick will be rough in texture, and since sandblasting removes the kiln-hardened outer fire-skin of the brick, it will become more susceptible to dirt build-up and moisture penetration. This is especially true of bricks made before the turn of the century.
Aggressive treatments, like chemical applications used to remove chalk, calcium carbonate, and rust, are best left to a professional. Chemicals must be spot tested in various concentrations. Too high of a concentration can etch the surface of the brick, damage window glass, or cause discoloration.