[Ktully1973]

I recently ripped down the wood knotty pine walls in my basement. There are piles of paint and concrete dust on the ground. The walls are almost turning into dust in some areas. How do I seal up the wall and prevent this from continuing? I was going to use drylock paint, but should I do something else before sanding and painting.

 

[Windows on Wash]

You needed to address the issue first and foremost. If there is moisture sitting up against the exterior that foundation wall, that needs to be addressed. If the concrete pour was bad and the concrete is breaking down, that, unfortunately, will need to be addressed.

Drylok paint is absolutely worthless and will do nothing but exacerbate the issue in most cases.

 

[Ktully1973]

I do have moisture issues in the basement. So I have a sump pump and dehumidifier to help. No moisture is coming through the walls. The house was build in the 1950's if that makes any difference.

 

[Windows on Wash]

We need to see what the grading and guttering are like on the exterior.

 

[Daniel Holzman]

Concrete is generally a very stable material, it can last thousands of years if properly designed and placed. I cannot tell from the photos what is going on. Soft, powdery concrete can occur if the mix is bad, the concrete is not vibrated in place during installation, or acidic water is migrating through the concrete. As noted by others, if the mix is bad, you cannot correct the problem by painting over the concrete.

You may need to hire a firm to take a few core samples and have them analyzed. Your problem may be efflorescence, which is a buildup of powdery material on the interior surface of the concrete. This is caused by water migrating through the concrete, which dissolves salts. As the water evaporates on the inside, the salts are deposited, and you get a powdery material. Efflorescence is not usually a major structural problem, more of a cosmetic issue, and can be stopped if you take care of the external water. You may need a local expert to look at the wall to determine if you have a bad mix or just efflorescence.