Insulating under house???

[butaford]

I have an older home with a raised foundation on tiers. I was thinking of insulating under the house using sheets of styrofoam. Is this a good idea? Has anyone here done this? Looking for pros and cons. I can only think of two concerns, trapping moisture and no way to inspect for termites without removing insulation. Got any ideas?

[tricia]

We had a house with a raised foundation in the early 80s we double insulated with polyetheline, seemed to work fine.