In walkways, these bricks are path to disaster

Chimney bricks have a high rate of water absorption.
Chimney bricks have a high rate of water absorption.Simon Bratt/Shutterstock

Q. I removed the centrally located, unlined chimney in my Victorian. It was a great idea; there are no leaks at the roof flashing now, and I have a big open space in the attic and a second-floor bedroom. It was all good, except I was left with a big pile of about 400 nasty bricks that are black on one side. Nobody wanted them, and it costs money to cart them away, so I decided to use them. They became little soldiers in the dirt along a concrete path. It was very neat-looking, elegant. They seem to be dusting up or decomposing. Aren’t these outdoor bricks?



A. Your bricks are falling apart because they are porous and have a high rate of water absorption. When they were used in the chimney, they were mostly protected, given time to dry out after getting wet. Your walkway is most likely pitched and drains water to the sides. These bricks are seeing way more moisture than before. Being in the ground makes this worse, by keeping them damp and constantly wicking moisture. The use of brick as a paving material here in the Northeast has greatly declined because they do crumble; however, there are a number of good clay-brick pavers available. Try salvaging what you can of your bricks and list them on Craigslist or sell them to a salvage company. They can be used for repairs, to match the materials in old buildings. But you’ll still have the unsalvageable ones to dispose of, I’m afraid. Toss them in a hired Dumpster or special disposal bag that can be hauled away.

Q. We put on an addition about 25 years ago. The basement doesn’t get water, but water vapor comes up through the concrete floor and walls. We run a dehumidifier, but anything that is put on the floor smells extremely mildewy within a couple of weeks. We stored kitchen chairs down there, and I had to clean the legs with bleach before we could use them. Our house is about 120 years old, and the original basement had a dirt floor and fieldstone walls. A layer of concrete was eventually added. That old basement never smells like mildew. Is there anything that we can seal the newer basement with to keep water vapor from coming through?



A. For the short term, you should keep running the dehumidifier and might want to use a fan to circulate the air. Your basement walls act like a huge sponge for outside water. The point here, though, is how moisture in the form of water vapor leaves the walls and migrates into the basement space. Keeping the condensation off the basement walls can be accomplished by adding rigid insulation or spray foam. Regarding your floor, I don’t have enough information to know whether you have groundwater issues. Mold loves to grow on organic material, so that makes the chair legs susceptible.

Rob Robillard is a general contractor, carpenter, editor of AConcordCarpenter.com, and principal of a carpentry and renovation business. Send your questions to homerepair@globe.com or tweet them to @globeaddress or @robertrobillard.