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Mold, mildew, and moss are fungi that thrive in damp and humid environments and old brick walls are one of the perfect breeding grounds for these organisms. Over time, brick becomes susceptible to the growth of these organisms as well as other climbing flora which, when left unchecked, can have adverse effects on both the aesthetic and structural integrity of your property. Because the brick walls absorb moisture and it can be challenging for them to ever dry out completely, mold, mildew, and moss grow rapidly, causing a variety of serious issues. Owners of historic brick homes throughout Washington, D.C., must keep an eye on the health of their property's exterior and take steps to mitigate the problems by preventing the growth of mold, mildew, and moss on old brick walls.

Nature vs. Old Brick

Nature inexorably reclaims what humanity has claimed for its own – one proof of this phenomenon is the way that mold, mildew, and moss growth spread across brick walls. These organisms can cause discoloration, staining, and even black spots on the brick's surface. This can be particularly problematic for commercial properties, where a clean and well-maintained exterior is crucial for attracting customers. Some homeowners may feel that the vegetal growth adds beauty or character to their older brick home, and while it can look charming in some cases, it can cause severe damage.

As mold, mildew, moss, and other climbing plants continue to thrive and spread, they inevitably cause structural damage to old brick walls. The acidic and penetrating fungi eat away at the surface of the brick. It holds moisture that weakens the mortar, causing it to crumble over time. In severe cases, this can even lead to the collapse of the entire wall. 

English Ivy may seem attractive climbing across your exterior brick walls, but it will work into your mortar joints and cause significant structural concerns. If any of the exterior walls of your historic brick home still have ivy, you may already have damage that needs professional repair.

 In addition to structural damage, mold, mildew, and moss can pose serious health risks to humans and animals. When these organisms are disturbed, they release spores into the air that can be inhaled. This can lead to respiratory issues, particularly those with pre-existing conditions like asthma or allergies.

Protect Your Historic Brick Home

Fortunately, you can take steps to prevent or mitigate mold, mildew, and moss growth on your historic brick home. One of the most effective methods is ensuring the walls are properly sealed and any cracks or gaps are filled. This can help prevent moisture from seeping into the bricks and create an environment that resists fungal growth.

Regular cleaning and maintenance are crucial for keeping mold, mildew, and moss at bay. This involves cleaning your brick using methods that will preserve it while removing the harmful growths that cause damage. Never pressure wash the bricks of your old historic home! Instead, use a gentle mixture of vinegar and water or dish detergent and baking soda to softly scrub away mold, moss, and mildew. Be sure to wear the proper protective gear to stay safe.


Mold, mildew, and moss on old brick walls can be severe problems for property owners. These organisms can not only cause unsightly discoloration but are capable of causing significant structural damage. The expert team at Renaissance Development can help you provide proper care for your historic brick home in Washington, D.C. Contact us today to learn more. 

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Post by Christina Wilson
Aug 3, 2023 8:30:00 AM