We have an indoor pool. Hey, came with the house. It's got windows all along one side so it's basically in a greenhouse, there's something to be said for swimming when it's snowing outside.
And said house is built into a hillside. So one of the walls of the pool room is basically a concrete basement wall. If we keep the pool covered, no worries. If we pull the cover off, the humidity in the pool room spikes to 100% and in the winter that wall starts to sweat bigtime because it's cooler than the room. The paint is coming off in big bubbles. I haven't checked to see if it's coming right off the concrete or if there's a primer layer that's staying attached yet.
The house is 35 years old and had a bunch of repair work done (broken pipe) before we got it so this wall was repainted. I don't know if this problem existed before that.
I assume I'll have to strip it back to concrete or at least that primer, because obviously painting over it won't solve the adhesion problem. Any suggestions for preventing this problem with the next coat? Is there special high humidity paint? Correct primer?
Sometimes folks use the wrong primer on the concrete. The finish paint bonds to the primer, but the primer doesn't stay attached to the concrete.
You need to determine if that is the case.
Ran into that a year ago on a job. We ended up blasting off all the paint and starting over.
If you get back to bare concrete I really like STM317's idea. Tile it.
Now if it was hydrostatic pressure, water pushing through the concrete from the outside... that's a whole different issue.
What about a couple of heat lights pointed at or near the wall? Maybe keeps the room warmer and especially the wall?
I know that's a left field suggestion, but it's cheapish.
I don't know if this helps.
Paint a concrete wall
Bob Villa paints a concrete wall
And I seem to remember something I read in the local paper, that you can't reliably paint concrete due to the moisture problem. But you can whitewash concrete.
Maybe useless whitewashing link
jgrewe
Reader
8/30/20 10:27 p.m.
It's not hydrostatic pressure though the wall. First, we are in a very, very dry area with excellent drainage on top of a hill- and it's pretty clearly related to that humidity spike when we uncover the pool. I'll look to see what's adhering to what.
There is a concrete basement foundation wall sealer water proofer kind of thing. I primed my workshop walls with it before painting. Found it at Home Depot, and I used one made by Behr.
It looks like the layer under the paint is a plaster skim coat. It feels to be in excellent condition where the paint has separated from it, so I'm guessing some sort of primer failure. It feels like raw plaster, not like it's coated with anything. I have the paints downstairs, they're generic Sherwin Williams paints as far as I can tell. No idea what primer - if any - was used. We only have trouble on this one wall.
Concrete is naturally very hydroscopic, it'll absorb any and all moisture.
Get some Super Diamond Clear and seal the hell out of the wall
