I’ve come across an old basement that’s has mildew on the inside of the foundation walls. The area has a lot of trees and bushes on the outside, and exposing the exterior of the wall in order to damp proof or water proof would be extremely difficult. Once cleaning the mold is their any reason that one could not seal the inside face of the foundation wall?
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Mold on masonry is fairly rare (the paint will mold, but not the masonry). Are you sure it isn't efflorescence?
That is likely, but the smell of mildew is also quiet strong. The wall has just been exposed which was hidden by the frost wall so the moisture was trapped against the foundation wall.
I think my question is answered. I need to stop the moisture from the outside.
Mold is generally dark colored, efflorescence is white or off-white. Bleach will turn mold instantly white, but have no noticible effect on efflorescence.
...
That mildew needs three things to grow.
Wramth
Moisture
Food
The masonry is not a viable food source for it. The only thing it can be feeding on is dust, pollen, etc that settles on the surface.
Clean it and keep it clean and you will have no problems.
You could use Boraxo and not rinse. Borates kill the growth.