Foam Insulation in Basement - evicting the rats

MacGuyveur · 08-26-2008, 09:40 AM

I have 30 year old batted fiberglass insulation between the joists of my unfinished basement floor. Rodents come in from the exterior and take up residence in the not so lovely fluffy stuff. It is falling and full of rat @#!. I have removed it, am attemting to put hardware cloth around entry points, etc. NOW, to replace the insulation I started with rigid polystyrene foam which is a pain to install, AND and figured out is VERY flamible. My guess is that it would not meet code. I just did one line of it before I woke up. I do not want to put the fiberglass insulation back because of the rats, although this seems to be industry standard . Question: Is the spray foam option a good one, and is it also very flamible? ALSO, I've seen kits on the internet, but am nervous about trying it because it is still pretty expensive. I HATE rats

. Any thoughts?

**Termite** · 08-26-2008, 09:47 AM

Yes, foamboard is incredibly flammable, and it puts off very toxic gas in a fire. The code and its listing don't allow it in exposed applications due to the potential for ignition. Although the listing may or may not specify, the code is specific to "areas accessible for service of utilities." This can be interpreted to mean piping, electrical wiring, furnaces, etc. The code requires an ignition barrier such as drywall, sheet metal, or plywood sheathing if foamboard is installed in such areas.

Ron6519 · 08-26-2008, 10:24 AM

Once you get rid of the rats, using fiberglass shouldn't be an issue. Rats congregate in an area for a reason. Look around outside, identify the reason and eliminate it. Overgrown properties, garbage not in proper containers or strewn about will attract these guys. Any neighbors fall into this catagory?
Ron

MacGuyveur · 08-26-2008, 11:37 AM

I got a couple of estimates on putting in the spray foam and it is coming out to around $2 per square foot. I've decided I don't want to do it myself. But I'm migrating back to simply plugging holes, cleaning up, and putting the fiberglass back in. Question: can you make a basement "too tight"? I have dehumidifiers going. Gas heat and water cooler are in the basement.