While working up a price quote with my local lumber yard for EPS foam I was warned about the possibility of carpenter ants invading the foam which happened in the local area with a few other places. He was not certain what sort of foam was used but could have been EPS. Does anyone have any direct negative experience with ants and EPS foam? I noticed Insulafoam, who I plan to get the EPS from does add some sort of substance to inhibit termites and ants.
Dave
Haines Alaska

Ants don't eat the EPS foam, they make nests in it. And they are not the only critters that like to live in foam. For that reason, foam should never be left exposed directly or even indirectly to the ground. (As in foundations) That being said, ICFs and/or SIPS and/or any other product using foam should be permanently shielded in some way. Also, in our area, we always use soil pre-treatment for pests and suggest annual re-treatment.
By the way, I don't know what type of product Insulafoam uses as an inhibitor, but several years ago, several companies were using borates for this purpose. Borates are great as wood preservatives and insecticides, but I heard some rumors that it was causing problems with the foam integrety. Don't know if this was true or not, but I would quiry my supplier about this before buying.

My plan is to build up on pilings with the area under the floor joists open so I think that would help me at least fend off an all out assault. My worry is that once in the foam with the type of continuous (non-thermal bridged) installation that they could take over, even in the roof. It has given me pause to maybe consider a more conventional approach to insulating. The type of construction I am wanting to do is called PERSIST (Pressure Equalized Rain Screen Insulated Structure Technique) which uses an inner structure with EPS on the outside of plywood and structure.
Similar to this:
http://www.cchrc.org/Reports/snapshot07-003remote.pdf
And this one  http://www.buildingscience.com/documents/primers/bsp-035-designs-that-work-very-cold-climate-juneau-ak/section-2-the-basic-very-cold-climate-house/

If the ants can get up inside the wall there would be no stopping them. They call for a bug screen along the base of the wall so will have to make absolutely certain it is a good continuous  one.
Thanks for any ideas and opinions posted...
Dave N
Haines AK

Carpenter ants only eat wet wood. Must lack saliva glans. Keep wood dry ,no ants.

I mean glands. That's what you get from a publix school education.