Most building managers already know that routine cleaning of exterior masonry is essential for maintaining a professional appearance that makes a good first impression.
However, there are many aesthetic and structural issues which develop over time and require more extensive restoration work to correct.
Rain, humidity, sunlight and chemical pollutants can all degrade the condition of the masonry. Dirt and debris running down the side of the building cause mold and mildew growth, creating unsightly dark streaks to appear. Moisture that seeps into cracks and openings may lead to even more extensive moisture damage. Ground level moisture can penetrate upward into the masonry, and salts from rainwater and de-icing products can deteriorate limestone and other porous building materials. Even the mortar between bricks will break down if not properly maintained.
A preventive approach to exterior maintenance helps to detect, correct and prevent masonry issues before they lead to more severe damage. To ensure best results, professional refinishers at Mid America Specialty Services utilize cleaning and sealing methods tailored to the needs of individual building materials such as brick, stone and concrete.
Routine Inspections
Masonry should be closely inspected at least once per year, and more frequently depending on building materials and local weather conditions.
Look for stains, streaks or mold or mildew growth, which are indicators of moisture intrusion. Other warning signs of masonry damage may include:
- Bowing or bulging near the foundation
- Crumbling or cracked masonry
- Unwanted plant growth, moss, mildew or mold
- Spalling, which occurs when the surface begins to flake off
- Blocked weep holes, which trap moisture underneath the surface
Don’t forget to inspect the mortar joints between bricks. Mortar doesn’t just hold bricks together. It also ensures that the weight of the building is evenly distributed. When it becomes damaged, it is less effective at supporting that weight. Signs of mortar degradation include cracks, holes, pits and sunken or missing mortar. Damaged mortar can be repaired through repointing, which involves removing chipped or cracked mortar and replacing it.
Cleaning & Restoration
Regular masonry cleaning prevents the buildup of algae, dirt and other pollutants which degrade the appearance of the building. It also removes dirt, efflorescence and water stains. A good rule of thumb is to have masonry cleaned at least twice per year and more often as needed. The goal of cleaning is to remove contaminants from the surface as safely as possible. For best results, choose the gentlest water pressure and cleaning agents necessary.
Water cleaning methods may include soaking, steaming or spray washing. Soaking is good for cleaning areas that aren’t exposed to rainwater. It involves gently spraying or misting the surface for up to a week, followed by a gentle water rinse. A steam wash is another low-pressure option that is good for cleaning intricately carved details.
A low- (100 psi or lower) or medium-pressure spray (300 to 400 psi) may be paired with a compatible detergent to safely remove accumulated dirt and grime. For stubborn stains, technicians may also use a natural or synthetic bristle brush. Metal brushes should be avoided, as these can cause ugly scratch marks. Water washing should be finished with a rinse to remove cleaning agents.
Cleaning products interact with dirt and debris, making them easier to rinse off. Professional refinishers will choose products that are compatible with the building material and the contaminants to be removed, such as dirt, paint, metal stains, plant growth or graffiti. Refer to the manufacturer’s instructions with respect to dwell time. Use a natural or synthetic brush as needed prior to rinsing.
Masonry cleaning should include unclogging weep holes to promote ventilation and reduce mold and mildew growth. Finally, it is essential to get rid of moss, mold, mildew and unwanted plant growth in order to deter moisture penetration.
Sealing for Protection
Limestone and other porous masonry must be sealed to prevent moisture penetration. A quality sealer should allow adequate ventilation and also protect against ultraviolet rays, oil stains and other contaminants. A sealed façade is easier to clean without the risk of water damage. Sealing should take place when the surface is completely dry, which may take a few days after cleaning.
With a regular program of inspection, cleaning and sealing, exterior masonry can remain in excellent condition for years to come. As MASS, our professional refinishers have the experience and know-how to preserve the beauty and value of your facade.
You can reach us at 800-544-4576 or contact us online.
