Why Are Older Brick Buildings More Vulnerable to Water Damage?

In older brick buildings, the mortar between bricks was often softer and more porous than modern mixes. Decades of weather, temperature swings, and moisture cause that mortar to erode and crack. These tiny gaps become entry points for water, especially during heavy rain or when the ground stays wet for days.

The bricks themselves can also become more absorbent over time. Older bricks were fired at lower temperatures, leaving them more porous. Once water gets into a brick, it can travel deep into the wall, carrying salts and minerals that later form white stains or cause the brick face to flake off, a process called spalling.

• Cracked mortar joints let water pass straight through
• Porous bricks soak up moisture like a sponge
• Spalling happens when trapped water freezes and expands
• Salt deposits weaken brick from the inside out
• Hidden damp spots often go unnoticed until damage is severe

Older brick buildings often sit on foundations that have settled unevenly over time. This can create small gaps between the foundation and the brick wall. Water from rain or runoff can pool there and seep upward into the lower courses of brick, especially if the ground slopes toward the building.

Gutters and downspouts on older structures may be undersized or poorly positioned. When they fail to channel water away, the soil next to the foundation becomes saturated. That constant moisture pressure pushes water through the foundation and into the brick, making the lower walls damp and vulnerable.

If you own an older brick building, start by checking the mortar and brick for visible cracks or missing chunks. Keep gutters and downspouts clear so water moves away from the foundation. Ensure the ground slopes away from the walls, and consider having a professional apply a breathable water repellent to the exterior.

Inside, look for damp spots, efflorescence (white powdery stains), or soft areas on walls. If you live in Port St. Lucie, keep an eye on the exterior after heavy storms. Catching problems early can save you from costly repairs. For any signs of water intrusion, contact a local water damage pro for a thorough assessment.