I've heard that painting mortared brick and stone can trap moisture and lead to damage, but I'm curious about why Drylok is seen as okay to use on basement and floor cement. Doesn't it also have the potential to cause moisture issues?
3 Answers
No freeze and thaw cycles in your basement really helps, too. Plus, in my experience, Drylok often chips off before it can do any major harm, so the risks seem lower compared to traditional paint.
Drylok is designed to be vapor permeable, meaning it can repel water while still allowing water vapor to escape slowly. So, if you put a plastic sheet over a wall coated with Drylok, you'll actually see condensation forming on the back of the plastic. It’s this property that sets it apart from regular paint, which can trap moisture.
I think Drylok can be a bit of a scam. Without a proper vapor barrier, it’s likely to flake off and, ultimately, weaken your foundation. If you're already using a vapor barrier, you probably don't even need Drylok. It might be more of a marketing ploy than a long-term solution.
Exactly! The focus should really be on addressing moisture issues outside rather than relying on something like Drylok.
That's true! Nowadays, modern construction usually skips interior vapor barriers for basement walls. We generally use permeable insulation materials, like foam boards, that allow moisture to evaporate instead. It’s better to focus on resolving moisture problems externally and beneath the floor to avoid trapping it inside.