Q. Should you weatherproof brick walls?

A. Brick walls are not weatherproof, cold/hot air and water can enter your house through the walls.

Unfortunately, many homeowners think brick walls are waterproof.

But the fact is – bricks can retain a large volume of water like a large sponge so do hot air and cold air too.

Q. What’s difference between waterproof and weatherproof?

A. Well, waterproof is good and works for newly fresh mortars but not for an old brick house.

Q. Is sealing brick a good idea?

A. Brick is extremely porous, so it can absorb water like a sponge, and over time, water absorption can cause crumbling and cracking in the brick.

Apply a sealer to your exterior brick for protection against water damage and minimize moss growth

How long it will last?

A. It would last long as you live!

Q. What starts Air Leakage, what drives it?

A. Air leakage often occur for any of these reasons:

Holes, cracks, gaps, seams, and penetrations. The larger the hole, the greater the air leakage. Large holes have higher priority for air sealing efforts. 

Driving force. A pressure difference that allows air to flow through a hole. Holes that experience stronger and more continuous driving forces have higher priority.

The common driving forces are:

Wind. Caused by weather conditions.

Stack effect. Upward air pressure due to the buoyancy of air.

Mechanical blower. Induced pressure imbalances caused by operation of fans and blowers.

Q. How can Wind cause the imbalance?

A. Wind is usually considered to be the primary driving force for air leakage, but, in most locations, wind is intermittent and relatively minor. When wind blows against a building, it creates a high-pressure zone on the windward side.

Outdoor air from the windward side infiltrates into the building, while air exits (exfiltrates) on the leeward side. Wind creates areas of differential pressure, which cause both infiltration and exfiltration. The degree to which wind contributes to air leakage depends on its velocity and duration.

The temperature difference between inside and outside causes warm air inside the home to rise, creating a driving force known as the stack effect. In the winter, cold air is drawn in at the bottom of the structure to replace the warm air that escapes near the top.

In homes with large holes in the attic and crawlspace or basement (or even chimneys), the stack effect can be a major contributor to air leakage, moisture and air quality problems. In the summer, the opposite can occur.

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