I've converted my 400 sqft garage into a gym and workshop, complete with spray foam insulation on the walls and roof. The garage is on a slope with the south wall about 4 feet below grade. I don't have any water coming through the walls, but I've noticed moisture buildup under the rubber mats I've laid down on the concrete slab. The floor is quite damaged with cracks and depressions. I'm considering adding insulation like Dricore subfloor panels, but I suspect the moisture is seeping up from the concrete. Should I seal the cracks first to prevent this, or is there a better way to tackle this? I'm located in Spokane, WA, where winters are wet and summers are dry. I want to address this without spending too much.
1 Answer
Concrete is porous, which means simply filling cracks and sealing might help a bit, but won't completely stop moisture from coming through. A good solution might be to roll out some thick plastic sheeting over the concrete to create a moisture barrier. Just keep in mind that this won't stop mold or mildew beneath the plastic, so consider painting the concrete with a mold-resistant product first. You can find options like the M-1 Advanced Mildewcide online or at a nearby home improvement store!
What type of paint would you recommend for this?