Should I Lay Down Plastic in My Crawlspace?
LESLIE: Now we’re heading over to Delaware where Margie has a crawlspace question. What can we help you with?
MARGIE: I’d like to know if you should put plastic on the ground underneath your house. We have a 3-foot – you can climb under there. Should we lay plastic on that for a barrier – for a moisture barrier? Underneath a ranch house.
LESLIE: What’s the – is it underneath the entire house or is it just under a certain area?
MARGIE: No, it’s underneath the entire house. You can crawl under and someone said you should put plastic on top of the dirt.
LESLIE: Now, are you having any moisture issues inside the house?
MARGIE: Not really. We were just thinking it would be a good idea to do that.
LESLIE: Now, generally, with an enclosed crawlspace or one that’s smaller scale to an entire home, we would always recommend putting down sort of a plastic sheathing. And you want to fill the entire space. And in areas where you do have to have seams, you want to make sure that you overlap, you know, a good foot or two so that it really lays down nicely.
Now, Tom, would you do that if it’s under the entire house?
TOM: Yeah, I’d put it down across the crawlspace floor, along the entire house, because it stops the moisture in the soil from wicking up and evaporating up into the air and then getting the insulation damp and making it ineffective. So, it’s always a good idea to have – it’s called a “vapor barrier” and have that down on top of that soil surface.
You also want to check the exterior, though, to make sure that your gutters are clean, the downspouts are extended. It’s part of a moisture-management solution. It’s not just [one-off] (ph).
LESLIE: You want to make sure you’re limiting the amount of moisture that actually gets to that – the dirt or the soil underneath the crawlspace. So if you make sure that your gutters are extending away from the house a good 3 feet or so and not depositing the water back towards that crawlspace – any sort of plant-embedded areas, you want to make sure that that soil slopes away. You just want to do your best that you can to move the moisture away.
MARGIE: OK. Thank you very much.
TOM: You’re welcome. Thanks so much for calling us at 888-MONEY-PIT.