Need to seal concrete basement wall

[TechBoyJK]

Hey All,

We're replacing a wall in our basement. It's a concrete foundation wall that we play to frame up with rigid foam insulation, install a bathroom, etc.

We've stripped it down to just the concrete, and I'm looking for something to seal it with. We're considering Drylok or Valspar Concrete Sealer, but we need to make sure it will play nice with the foam insulation adhesive and won't cause any other issues.

We've also been recommended to use Zinsser Perma-white which not only acts as a sealant, but since its water based it plays more nicely with water, as well as provides mold/mildew protection.

Thoughts?

 

[mdram]

purpose of sealing? it should be sealed on the outside to keep water out

 

[TechBoyJK]

purpose of sealing? it should be sealed on the outside to keep water out

To prevent water from coming in. There's no known or visible cracks, just wanted to do something to help keep the basement dry while the wall was exposed. Once the foam goes up it's no turning back.

Ideally we'd seal it from the outside, but we don't have that option.

I think this why I was recommended the Zinsser Perma-white because it's a paint that prevents mold/mildew but is water based.

 

[bigi]

I am afraid that unless you do it from outside properly, there is not much you can do that will provide tangible benefits in a long run.

 

[Dranoche]

Do you have any moisture issues now? Is there any sign of efflorescence? If not, then the wall is probably already sealed from the outside with a membrane and/or an asphalt sealer, and probably has a drain as well.

If you do have water issues, applying a sealer now on the inside may be difficult, and much less effective than from the outside. A more complete solution from the inside would be to install a drainage mat against the walls, but this would also require the addition of a drain at the bottom of the tile and point to daylight the drain, or a permanent sump.

 

[TechBoyJK]

Do you have any moisture issues now? Is there any sign of efflorescence? If not, then the wall is probably already sealed from the outside with a membrane and/or an asphalt sealer, and probably has a drain as well.

If you do have water issues, applying a sealer now on the inside may be difficult, and much less effective than from the outside. A more complete solution from the inside would be to install a drainage mat against the walls, but this would also require the addition of a drain at the bottom of the tile and point to daylight the drain, or a permanent sump.

No issues currently. This is just a matter of having access to an exposed wall that's going to be likely covered for the next 20 years.

 

[homebrew2ny]

Drylok is basically the gold standard for what you need.

 

[piasabird]

If you live in a place where you get a lot of rain and your yard does not drain well, when the water content in the soil builds up it will find a way through. I dont care what kind of sealer you use on the inside.

A sub-pump might help.

This is my opinion.

 

[Exterous]

Drylok is basically the gold standard for what you need.

Thats what I put down in my basement. We have a sump pump and I did the DIY moisture test (tape plastic to the ground for several days) and no issue but there were some very small spots of efflorescence. I was only doing the floor of a room I was finishing so if it doesn't work it was only $50 that was wasted (I was more concerned with moisture getting into the wood. The pt lumber is also on top of a strip of sill seal)