efflourescence & mortar repair question

Old 09-02-05, 08:48 AM
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Red face efflourescence & mortar repair question

I have a 80 year old house with a limestone foundation. At least I think it's limestone. May be a mixture of granite/limestone. I see what I think may be efflouresence (salt crystals) on some of the stones on the interior basement walls. I have also noticed spots of soft mortar. When I bought the house, the gutters were falling off. I have since replaced the roof, gutters, downspouts. All downspouts tie into the sewer system--city code.

My question is what should I now to clean off the walls and prepare them for painting. I thought I should clean them off with a wire brush, repair any soft or loose mortar, then paint the walls with drylock (or some other product). I also wondered should I clean the walls with some sort of cleaner?

I also wondered if there was something I should do to the exterior side basement walls. Perhaps apply some sort of caulk where the side of the foundation meets the sidewalk. Not sure what to do, so I am open to suggestions.
Old 09-02-05, 09:56 AM
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efflourescence & mortar repair question

Whatever you can do on the outside will help. If you can caulk or seal the joint, good. I assume you sidewalk slopes away from the house.

Since are going to paint the interior, preparation is necessary. Washing the wall down with an acidic solution (nothing fancy - vinegar and water) sould remove the efflorescence. Brushing will also help. Your stone foundation is probably quite irregular, but you could fill in some mortar joints for appearance purposes.

Your coating could be DryLok or one of the cement based waterproofing materials (Thoroseal, etc.). Just apply according to instructions.

Your foundation made it through 80 years and it should outlast your house with a little care.


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