A wet basement in Cincinnati made me rethink my moisture barrier method

I was installing a floating LVP floor in a 1950s house there last month, and the homeowner insisted the concrete slab was bone dry. Two days after we finished, I got a call about cupping along the wall. Turns out a hidden downspout was dumping water right against the foundation. Now I won't start a job without doing a calcium chloride test first, even if the client says it's fine. How do you guys handle client pushback on extra prep steps?

3 comments

3 Comments

morgan9152mo ago

That's a really good point about the plastic sheet test. I read an article from a restoration company that said the same thing. They called the plastic sheet a "qualitative" test for liquid water, while the calcium chloride kit gives you a "number" for vapor. In a case like that downspout, you need to look for the water itself, not just the vapor coming up. It's two different problems needing two different checks. I've started explaining it to clients that way, that we're checking for both types of moisture. It helps them understand why both steps matter.

troy_palmer7610d ago

Start by saying I mean it's really not that deep for most jobs. I've done a ton of LVP installs in older basements and just slapped down some vapor barrier plastic and called it good. Never had a call back. The hidden downspout thing is a freak issue, not something you're gonna catch with a test every time. Idk, seems like you could just check the outside grading and downspouts before you start instead of waiting for a problem. Maybe it's just me but all this testing sounds like overkill for a typical basement floor.

margaretj402mo ago

You mentioned doing a calcium chloride test, but that's for measuring moisture vapor emission rate through a slab. For a wet basement from an outside leak, a plastic sheet taped down tight for 24 hours is the better check for liquid water. The calcium test wouldn't have caught that downspout problem either.