Insulating Crawl Space

[SpiderMan]

I'm spending a few hours every day tearing the old damp fiberglass insulation out from under my house. I'd like to insulate the crawl space when I'm done by attaching rigid foam insulation to the walls. A contractor will be installing a CleanSpace liner and sump pumps in a few weeks.

Right now I have a few questions: What kind of insulation should I use? I find both FoamulaR and polyisocyanurate at my local dealers.

The second question is about attachment method. Do I glue the foam to the wall? Screw it to the wall? Use furring strips?

I know water comes in at the base of the wall, so I want to leave a gap there, probably 3/4" or so. Does this make sense?

Also, the contractor told me they attach the CleanSpace liner about 3" down from the top of the wall. If I attach the foam 6" from the top of the wall, will that leave them enough space?

I'm obviously assuming that the insulation gets installed, then the CleanSpace liner goes on top of it.

Thanks for your help.

[Crawl Space MD]

Thank you for your inquiry and for using a certified CleanSpace installer.
Rigid foam insulation is a good way to insulate your crawl space. You can glue it to the foundation walls and our installers will attach the liner over the insulation. We will use fasteners to attach the liner to the wall and seal with a textured caulk.It is a good idea to keep the insulation down a few inches as you discussed.
Thanks again.
md