# XPS, Spray foam and pests?



## Windows on Wash (Aug 30, 2011)

Can and do they eat through it, yes.

It is not usually the norm in what I have seen. They want to just shove their little heads through more readily available gaps and cracks. 

If you are concerned about them, close up the larger holes with sealant and mesh prior to the foam. 

Most of the larger gaps should be secured from the exterior anyway as a general best practice.


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## gizzygone (Jul 26, 2012)

Windows on Wash said:


> Can and do they eat through it, yes.
> 
> It is not usually the norm in what I have seen. They want to just shove their little heads through more readily available gaps and cracks.
> 
> ...


Well, under the bulkhead there was a door that I pulled out from the slab and into the the new framing: and I used pressure treated lumber to close the gap (but again, I wedged the lumber up on the foam for water reasons). 

So it's effectively protected from the exterior with the bulkhead, but given the droppings I found under the old door sill, and the amount of bugs, I think it's safe to say it's not protected enough. 

I supposed I could put some mouse traps down there just to be extra sure, but I wasn't sure if mice would just chew on the foam because...


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## Windows on Wash (Aug 30, 2011)

You are probably good if the gaps are pretty tight with the wood. Again, if you are concerned, close them with a good exterior sealant prior to foam


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