What kind of sealer can we use in our basement, walls have been painted.?

Question

House was built in 1949, full basement. Water seapage is mainly through the walls. We do have a sump pump.

Answer 1

the only way to seal a basement wall is from the outside.with a sealer designed for that purpose

Answer 2

1. is the grade away, or toward the foundation? If it's sloping toward the foundation, grade it away from it.
2. Ensure that your gutters work properly and that they drain well away from the foundation.
3. If you have clay in the soil surrounding the house, that can be a problem, as it doesn't percolate well, and maybe a french drain may carry enough water away to solve the problem.

If you can find the solution to your problem in one of the above questions, then use the remedy pursuant to it, because if the masonry is already painted on the inside, 20 coats of sealer won't do a thing, because it can't penetrate and that's how that stuff works.

As a last resort, you can trench out the foundation, let it dry out and apply an exterior sealer, but that's no fun at all.