Termites: OK to Insulate after Treatment?

LESLIE: Greg in Illinois is having an issue with termites. How can we help you today?

GREG: Hi, I’m trying to get ready to insulate my crawlspace and I’d love to do it with spray foam insulation.

TOM: OK.

GREG: We’ve had some termites about three years ago. I had them come out and treat. They said it’d be good for 10 years. So, should I spray foam; should I go another route? What are your suggestions?

TOM: Yeah, what did you treat the termites with?

GREG: I had a rather well-known pest company come out and they did the whole drill a hole every 12 inches on the outside of the foundation wall and fill it up with whatever chemical they use.

TOM: OK, do you know if they used a product called Termidor?

GREG: I don’t.

TOM: OK. Well, you ought to find out what pesticide was used but it was probably an undetectable termidicide, which is good because the termites don’t know it’s there and they pass through it and get it on their bodies and then go back down to the nest and spread it to all their termites friends and that takes care of the whole colony.

As far as the insulation is concerned, you’re talking about like a product such as isonene or a product of that nature where you spray insulation on and it expands. It’s good stuff. It really seals in as well as insulates; but you know, at the same token, it might be a little bit overkill. You could probably get a decent amount of insulation and still have accessibility to those critical structural areas if you used just some pink insulation.

GREG: OK. OK.

TOM: But I would fill in the batt; fill in the space between the joist with large, deep batts. Use as much insulation as you can. You’re going to support it with wires that actually sort of support that piece of insulation up inside the floor space.

GREG: Is it enough to do that or do the foundation walls?

TOM: Well, you can actually do both.

GREG: OK.

TOM: Yeah, you could use the foam panels for the walls, but definitely do the floor with the batt insulation. Make sure it’s unfaced fiberglass batts and you’ll be good to go.