Concrete slab taught me a harsh lesson about moisture

Used to skip the plastic under padding. Thought it was an upsell trick. A basement job got moldy in weeks. Now I use a moisture barrier every time.

3 comments

3 Comments

ward.jamie1mo ago

Man, you learn that one the hard way just once, don't you? We put laminate right on a slab in a sunroom addition years back, and it was cupping and buckling before the season changed. The amount of dampness that comes up through concrete is no joke. I had to rip it all out, dry everything, and start over with a proper barrier. It turns a weekend project into a massive headache real fast. Never making that mistake again.

the_oscar1mo ago

Dealt with a soggy slab in my garage conversion. Thought the concrete was dry enough after a week, but I was wrong. Had to pull up the flooring and lay down a proper vapor barrier. Now I check moisture levels with a meter before any install.

mark_hayes1mo ago

Honestly though, is it always that big of a deal? I get that basements are wet, but for a garage or a sunroom on a slab, it feels like overkill. Concrete's been fine for decades under tiles and stuff. Maybe it's just certain climates or really cheap flooring that can't handle a little damp. I've seen plenty of floors go right on the slab and hold up just fine.