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How Spray Foam Insulation Increases Termite Risk

February 18, 2019

Announcer: Farm and Family is a production of the Mississippi State University Extension Service.

Amy Myers: Today, we're talking about how spray foam insulation increases termites risk. Hello. I'm Amy Myers, and welcome to Farm and Family. Today, we're speaking with Dr. Blake Layton, Mississippi State University State Extension entomologist. Dr. Layton, this is a relatively new concern. First, what is spray foam insulation, and how is it related to risks of termite infestation?

Blake Layton: Spray foam insulation is applied as a liquid product, and then it expands and hardens to produce a thick layer of insulation, so it's a good insulation too. This can increase the risk of termite infestation, because it covers up the wood, the wall coverings, and other areas where it might be possible to detect termite infestation, so it makes it much more difficult.

Amy Myers: So, how are inspectors and home owners able to recognize termite infestations?

Blake Layton: Under the best of conditions termite infestations can be really hard to find. The easiest way maybe is if you have a swarm that emerges in your house, that's pretty obvious, or if you see some damage, you're doing home repairs or structural repairs and you find termite damage, but when most of these inspections are done, what you're looking for is something much more subtle than that, either by crawling under the house looking for mud tubes that might go up the inside foundation wall, or structural support elements, or things of that nature, or looking for subtle signs of termites feeding in the wood. They don't like to feed at the exterior of the wood. When they happen to break out, they might patch that up with little spots of mud and stay inside the wood, but at least a good technician can spot that little pinhole, or patch of mud, or those mud [inaudible 00:01:43]. Those are the kinds of things that we have to be able to spot.

Amy Myers: How costly is it to repair termite damage?

Blake Layton: That varies, depending on how severe that termite damage is. So, I've seen cases where, yeah, we had termite infestation, there was a little damage there, didn't even need to be repaired. Maybe they were in the subfloor or somewhere like that. They'd eaten some timbers, but they didn't structurally affect the strength, so no repair was necessary, other than treating the termites. The next level up is, well, there was a little cosmetic damage, like on the inside of a kitchen or somewhere. Maybe a few hundred dollars repaired that. If an infestation goes undetected for long periods of time and they're able to cause a lot of damage, then you can be talking about repair bills in the tens of thousands and even in some cases higher than that.

Amy Myers: Can spray foam insulation actually increase the potential for termite problems?

Blake Layton: It can also do that. I think the big concern is that it can hide termite infestations, but because the spray foam insulation can also trap water in places, and moisture in wood is a big what we refer to as a conducive condition for termites ... They like moist wood, and that increases the potential for termites to set up shop, so to speak, and to thrive really well. In certain cases this spray foam insulation can trap moisture or make it more difficult to detect the moisture problem, so you don't correct that, and then you get the termite problem, which is also more difficult to detect.

Amy Myers: If I'm buying a house, what do I need to know?

Blake Layton: Whether that house has spray foam insulation or not, it needs to be inspected and have done what is called a wood destroying insect report, where a certified technician will inspect that house, do their very best to find termites and other wood destroying insects, if they're there, give a report showing whether or not they found them. That doesn't necessarily mean that house is free of termites. It just means that trained technician did their best to find termite, and either they didn't find them, or if they did, they'll indicate that on the report.

If there's spray foam insulation there, that will make it more difficult for that technician to do their job. Recently we had a change in the wording and information on this wood destroying insect report, so that spray foam insulation is considered as exclusion, meaning that the technician will indicate, well, there's spray foam insulation in these areas. I can't see back there. I can't say yay or nay whether there's a termite infestation.

Amy Myers: Let's just say that I am having spray foam insulation installed. What do I do?

Blake Layton: There are two types of spray foam, open sell and closed sell, and it's used in different areas. Then there are also ways that it can be installed. There's some restrictions, like leaving a six inch gap between the ground and the beginning of the foam insulation and maybe a six or three inch gap between the top of the insulation and where it might meet subfloors. There's some things like that that can at least give a technician some places to look. Being aware of those and looking into those can be key.

Amy Myers: How do we find more information?

Blake Layton: We have a pretty extensive website on termites. You can readily find that by going into your search engine and doing a search for termites Mississippi State, and it'll be listed there near the top.

Amy Myers: Today, we've been speaking with Blake Layton, entomologist. I'm Amy Myers, and this has been Farm and Family.

Announcer: Farm and Family is a production of the Mississippi State University Extension Service.

Department: Biochemistry, Molecular Biology, Entomology and Plant Pathology

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