Alternative to fiberglass insulation in a crawl space

[Dan]

Bought a mid 1970's vintage house in the Seattle area last April. The house has had ongoing problems with rats in the crawl space. If the assortment of insulation between the joists is any indication, some has been replaced at least twice, likely from this problem, and a bunch of it is torn/pulled down/soiled now from the animals as well. It goes without saying that the goal is to keep rodents out of the space, and I am working on that (just found one primary point of entry that was missed by TWO exterminators that I know of, and probably more). However I plan to have ALL the fiberglass removed & replaced with new insulation. I am wondering if there is any type of insulation, maybe a rigid foam board material, or something sprayed on, which is resistant if not impervious to rodents getting into it, on top of it, pulling it down & nesting in it. Any helpful insights into this appreciated.

Dan

[Rick Blaine]

Don't know how rat resistant it is, but you might consider something like this:

-- "Tell me what I should do, Annie." "Stay. Here. Forever." - Life On Mars

[Norminn]

Rats can chew through wood and metal, so impervious would have to be something special. With a long-term infestation, I wonder what the surrounding properties are like - open trash containers, pet food or other food available? Rural? City? If you have neighbors nearby, do they also have rat problems?

[JoeSpareBedroom]

Do you need to get under there easily for maintenace of pipes or wiring, or could it be blocked off "with extreme prejudice", as assassins say in movies?

[HeyBub]

Get a device called "Barn Cat." Maybe two. It's ecologically sound.

[BETA-32]

I think the main thing to do first is eliminate the access to the crawl space from the outside and eliminate any sources of food and water.

Here's some additional rat info:

[JoeSpareBedroom]

And more:

[Dan]

Thanks for the replies. The house is in a suburban area, but heavily wooded. I don't think it's an issue of garbage or dog food. The footprint of the crawlspace is probably 1300 sq'. If you're as small and clever as a rat, and basically have nothing else to do when not looking for food & screwing, the odds of you finding a gap for entry are pretty favorable. I'm thinking given the history, and the complexity of finding & irreversibly sealing off every conceivable entry point, if there were an insulation alternative that wasn't quite as accomodating as fiberglass batts, it might be a good choice.

Dan

[JoeSpareBedroom]

Do you need regular access to the crawlspace for maintenance?

[Heathcliff]

I don't know of any insulation that would be impervious to rats or mice. Maybe it would be better to just go with no insulation for now, until you are sure the rodent problem is licked. Meanwhile you can see how much it affects your heat bill, cold floors, etc. and then decide whether to try insulating again. -- H

[hallerb]

=BDThe house

cover affected area with screen like hardware cloth or chicken wire.

insulate floor well say blown in foam then ventilate the lower part well

rats like warm spot so they will move to your neighbors crawl space:)

[Dan]

Occasional access, anyway. There is one door on an exterior wall, but it's sealed well & isn't the problem.

[JoeSpareBedroom]

Although the idea might be impractical due to expense, I would take some pictures and show them to a couple of sheet metal fabricators. Perforated aluminum over the insulation or some such thing.....vague idea. There has to be something rats can't chew through.