Humid Crawl Space
LESLIE: Dave in Alabama, you’ve got The Money Pit. How can we help you today?
DAVE: I have a crawlspace that’s humid and I was thinking of putting down some gravel and plastic sheeting and I was wondering whether the plastic sheeting should go on top of the gravel or below the gravel or forego the plastic sheeting altogether.
TOM: What’s the purpose of the gravel?
DAVE: The purpose of the gravel was either to protect the sheeting or, I was thinking, to keep it drier underneath the plastic.
TOM: Well, what kind of a surface do you have on the crawlspace floor right now, David?
DAVE: I just have dirt.
TOM: Just dirt? All you need to do is to put the plastic sheeting on top of the dirt. The gravel is not really necessary. What you’re doing is just you’re basically stopping the evaporation of moisture off the soil up into the rest of the house. So what you want to do is you want to use very good-quality, thick plastic sheeting; you want as few seams as possible; and just lay it out there across the soil and you’ll see an immediate difference.
DAVE: OK. They do talk about gravel, though. Do you just find it doesn’t help at all?
TOM: It doesn’t really help at all. It doesn’t serve any purpose. You want to stop water from evaporating off the soil and getting into the air and making the crawlspace damp and moist. So, to do that, all you need to do is to cover that surface with plastic sheets.
LESLIE: (overlapping voices) And keep the moisture below it.
TOM: There’s no value to stone in this equation. (Dave chuckles) No value whatsoever. OK. This is an easier project than what you were thinking.
DAVE: Yeah, it is.
TOM: And a lot easier on your back, too.
TOM: Think about all of the money you’re going to save in chiropractic visits. (Leslie and Dave chuckle) Alright, David? Good luck with that project. Go get to it, alright?
TOM: The number is 1-888-MONEY-PIT. Thanks so much for calling us.