I read an article about winterizing your home and there was a comment that chalky substance on brick can indicate a serious problem, yet they never state the problem. I own a 1940's Georgian and the only area where we can see the brick is in the basement where the water heater and furnace are located. There is a white chalky substance on the brick and floor. What is it, is it dangerous, and who do I contact?
It's not dangerous. (I read about it awhile back in a book about bricklaying.) Now, I don't remember the precise cause, but I believe it has to do with the mortar setting up improperly. I believe the way to get rid of the white stuff is with a very mild wash of muratic acid.