Insulation in Your Crawlspace
LESLIE: Chris in Texas is calling in with an insulation question. What can we do for you today?CHRIS: Yes, I’ve had some work done on my – I’ve got a [pin beam] (ph) and I had some work done on the foundation; where they went in there and leveled the house and everything and they pulled all the old insulation out between the floor joists. And this summer, after they did that, I realized it got extremely hot in the house …TOM and LESLIE: Mm-hmm.CHRIS: … and I was wanting to know – I went back with hardy backer siding that I cut down for the underpinning on it.TOM: OK.CHRIS: And I was wanting to know if it would be worth my while to put like a ¾-inch foam; maybe Liquid Nail it to the backside of the hardy backer. Would that help at all?TOM: You’re on a crawlspace; is that correct?CHRIS: Correct.TOM: OK. And this siding basically goes from the house down to grade?CHRIS: Correct.TOM: And the insulation that they removed was in the floor joists between the soil and the underside of the house?CHRIS: Yes, sir. Yes, sir.TOM: OK, and did you replace that insulation?CHRIS: No, sir. I didn’t want to go back with it for moisture reasons and it had a real flimsy net that was holding it up in the bottom of the joist.TOM: Here’s what you should do, Chris. You should replace the insulation. You don’t need to use the net. You can use wire insulation holders which go between the joists.LESLIE: They’re like little straps.TOM: In terms of the moisture, you can put a humidistat in that crawlspace area and wire it to crawlspace ventilation fans so that when it becomes damp and humid down there, the humidistat will bring the fans on. That will draw drier air through that space and warm it up. But I think that’s going to be better for you than trying to insulate these side walls of the crawlspace. The best place to insulate the floor is in that floor space. That’s going to be responsible for about 15 percent of your heat loss and down there, it’s going to make a difference on your air conditioning bills as well.CHRIS: Alrighty. I sure do appreciate it.TOM: You’re welcome. Good luck with that project. Thanks so much for calling us at 1-888-MONEY-PIT.