Efflorescence / spalling in brick basement
I think I have an efflorescence/spalling problem in my basement foundation walls. This will be a bit of a long post as I want to include any details that may be relevant.
I’m not sure of a few things about it:
A) How much of a problem it is (cosmetic or structural?)
B) If the paint on the basement walls is a contributor
C) What the source of the moisture is (although I have suspicions)
Photos posted here: http://imgur.com/a/7TtkL
A bit of background:
The efflorescence is on two walls of the brick foundation wall in my basement. The efflorescence runs horizontally, with the worst parts in a band roughly a foot below ground level. The two walls that don’t have any problems are the northern wall, shared with my neighbor (it’s a semi detached house), and the Western wall, at the front of the house, where the front porch awning is, I assume, keeping the ground dry. The walls are mutli-wythe, with the exterior brick a textured red, and the interior bricks are solid and greyish. I don’t see any efflorescence on the outside of the building (although if it’s at the same height as inside then it would be underground).
The southern wall has an asphalt driveway between it and my neighbor, which comes right up to the brick. There are some cracks in the asphalt where it touches the wall, which I suspect of letting water in. Based on advice from another post here I will be ceiling those cracks with caulk. (https://www.greenbuildingadvisor.com/community/forum/general-questions/37750/sealing-meeting-point-brick-wall-and-asphalt-driveway)
A) On the vast majority of the affected areas, it seems to be only the paint that is affected. At one point though, underneath the bubbling paint, there is a thin layer of the brick that felt crumbly and powdered off when I touched it. Underneath that was normal hard brick.
B) Would I have any problem at all if the walls were not painted? Can the paint be preventing the brick from drying properly or something?
C) Given that I don’t see any efflorescence on the wall that’s shared with the neighbor, or on the wall whose adjoining ground is protected by the front porch awning, I’m thinking the water must be coming from the rain and not capillary action. Does that sound right? One thing that puzzles me is that the basement is dry, no water seeping in even on very very rainy days.
Thanks very much,
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