My wife and I moved into a new condominium building in March 2009. When it rains and there’s heavy wind, we get water leaking through the brick. A gentle rain shower with the rain falling straight down causes no problems. What is causing the problem? There are many older brick buildings on the street that are well over 100 years old and none of them leak. Is there anything that can be done that will stop the leaks, or do the exterior walls have to be completely rebuilt? Stanley P., Brooklyn, N.Y.

 

It’s a shame you’re experiencing this common problem. Not too many years ago I used to do quite a bit of expert witness work in construction-defect cases. I was the lead witness in a huge case in the Midwest against a very large builder. He built many brick-veneer homes and every one of them had leakage similar to what you describe. My testimony about what was going on and how to fix it carried the day for the homeowners.

Two hundred years ago this leakage issue was known. The builders who experienced leakage solved the problem by modifying how they built solid masonry buildings. They used different brick and they used a lime mortar different from today’s high-strength mortars. The lime mortar has a unique self-healing property where it can grow new crystals when a hairline crack develops. It’s too bad most masons don’t use this lime mortar in modern construction.

Your new condominium building and the older solid masonry buildings in your neighborhood may look similar on the outside, but that’s where it stops. The older brick buildings on your street have exterior walls that contain a minimum of two layers of brick. Some buildings have exterior walls that have three layers of brick.

The builders of old discovered that the brick you see on the outside needs to be a hard brick that resists weathering. The brick they used there was fired in the kilns for a longer time and at a hotter temperature. Some types of brick made in this way are so hard they can resist Mother Nature’s punishment for hundreds of years.

But the brick masons discovered they also needed a softer brick that soaks up water. This was the brick they placed behind the one you see on the outside of the old buildings. The softer brick sucked up the rain water and then allowed it to evaporate back to the exterior of the building just after the rainstorm ended.

This leakage has been well documented by building scientists for decades. The Brick Industry Association (BIA) has technical notes and bulletins that talk about this leakage and how to prevent it when building. Your building’s architect and builder should have followed the advice given by the BIA. These technical bulletins have been available for free for decades and can now be accessed easily from the BIA web site (www.gobrick.com).

- Tim Carter is a columnist for Tribune Media Services. Contact him through his web site at www.askthebuilder.com.

Read the full article as it appeared in The Washington Post.