Brick Houses

William Kibbel III, The Home Inspector

Dear Home Inspector: Why would anyone want to paint over a brick house -- especially an early 19th century home? Like many of the historic homes in our neighborhood, our house is painted, and we'd like to return it to natural brick. I've heard that sandblasting off the paint can damage the bricks. Is there some other method to remove the paint? How about power washing?

It's a common misconception that painting brick houses is a 20th century aberration. Some historic brick houses were painted very early on in their lives. Then, as now, there were several reasons for painting brick:

  • To conceal alterations, like previous repairs, bricked up windows, or door openings.
  • To cover up a century of coal soot, grime or graffiti.
  • Attempting to seal and protect old, spalled bricks.
  • To disguise or protect poor quality bricks.
  • As a design feature.
  • Vinyl siding hadn't been invented yet.

damaged brick
Erosion of the hard surface of this historic brick was the unfortunate (but common) result of sandblasting.

Paint can successfully be removed from brick exteriors provided the bricks were in good shape before they were painted. Unfortunately, proper paint removal is a tedious job. You mention sandblasting and power washing, and I can understand the temptation to find an easy way to remove the paint. But aiming a piece of equipment that looks like heavy artillery and firing it at an old building is something that should be avoided.

I've seen plenty of disasters from improper methods of removing paint, stucco or grime from old brick buildings. Sandblasting isn't the only culprit, but it is among the worst. Pressure washing also can quickly erode the surface of bricks. Some caustic chemical solutions can cause surface failures or can change the color of old bricks. Even low-pressure washing or gentle liquid chemical solutions can force excessive moisture through the porous brick surface and cause damage. Damage is especially likely if the brick can't dry completely before freezing weather.

Clay bricks are heat fired, producing a hard outside skin. Paint removal often damages this hard surface, leaving the soft, porous inner part of the clay brick susceptible to erosion, moisture intrusion and freeze damage. Rapid deterioration is then likely to occur, resulting in the need for major repairs. Old bricks are the most likely to be damaged, because before 1870, bricks were molded by hand. The firing was often uneven, and final quality depended on the type of clay used and the skill of the brick maker. Modern bricks are more uniform and are harder in the center, but even they can damaged by harsh methods of paint removal. Their surfaces can be severely pitted and micro-cracks will make the bricks less able to withstand the elements.

It's no wonder that once painted, many brick buildings remain painted.

Best method: Gel or paste removers

In my experience, a paint removal system that uses a gel or paste to dissolve the paint is least likely to cause damage to historic bricks. Most paint before 1970 contained lead, making removal a potential safety and environmental hazard. Finding a safe method for exterior lead paint abatement has led to products that can be applied to large surfaces and that contain the removed paint for proper disposal.

The safest method employs strips of fabric material that are applied over the paint removal paste. When the paint softens, it adheres to the fabric and the whole mess can be peeled off without dispersing lead paint chips throughout the neighborhood. Some of these stripping chemicals now are biodegradable or non-toxic. Not only are these formulas safer for people and the environment, the less caustic chemicals are less likely to cause damage to historic bricks.

Test A Small Area First

Before stripping the paint off your house, you should first test the procedure on a small, inconspicuous area. This test can help you determine several things:

  • The effectiveness of the paint removal system.
  • The condition of the bricks under the paint.
  • How the chemicals affect the bricks
  • How much work removing all the paint will be.

Some stubborn paint and chemicals will remain and will need to be cleaned off after the initial paint removal. Scrubbing with a stiff bristle brush (not a wire brush) and rinsing with clean water, using no pressure, is least likely to cause damage or force excessive moisture into soft bricks. Any paint removal should be completed months ahead of freezing weather to allow any moisture to migrate out of the bricks and mortar.

damaged brick
It's easy to see why the owner of this building chose to paint the heavily damaged brick.

After All That, Repainting

Of course, removing the paint might just reveal the reason your house was painted in the first place. If bricks are spalled, damaged or of inferior quality, your best recourse is to repaint. Spalling is the partial loss of masonry material, and is caused by water trapped in a masonry system. Leaking roofs, leaking plumbing and other systems problems are sources of trapped water.

Brick should be painted with latex paint or a lime wash. Both are considered breathable coatings. They allow water vapor, but not liquid water, to pass through the masonry. Waterproof (as opposed to water repellant) coatings should not be applied to above ground masonry house sections.

If you really want the look of natural brick, but must paint, take heart. I've seen quite a few old brick buildings that were painted brick red with all of the mortar joints meticulously painted white. I couldn't even tell that many of these homes were painted until I was a few feet away.

About the Author
William Kibbel III is a home inspector and restoration consultant specializing in historic residential and commercial buildings. He is vice president of Tri-County Inspection Company, serving Southeastern Pennsylvania and Central New Jersey.

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