Insulation, Radiant and Vapor Barriers - basement insulation

Hello
I have a split level and a finished basement, I have a crawl space in the basement that is just a concrete floor and cinderblock walls. Directly above the space is my kitchen and living room. My question is what would be the best to put along the cinderblock walls to keep the cool air out. I put pieces of insulation in the sill plates, but I wanted to put something along the walls to keep the upstairs warmer. Any help would be appreciated. Thank you very much.
Larry

Crawl spaces in this style construction, in my experience, have enough

''headroom'' to benefit from insulated foundation walls without the need of

ventilation. I'm not referring to any particular codes or studies, just my

experience of not finding moisture problems in crawlspaces with ''generous''

height and concrete floors. One of the most common choices of foundation

insulation is sheets of foam. The problem with foam is the requirement to

install 1/2'' drywall over the interior face of it , for fire safety. The same

requirement exists for rolls of fiberglass with paper face barrier on it. You

could install the fiberglass with paper to the blocks, although that violates

the rule of the moisture barrier to the ''heated'' side. Maybe the best

solution is the use of foil faced fiberglass rolls, hung vertically from the sill

plate and vertical edges taped together.

What about the foam insulation I think its 1 or 2 inches thick that can be put up against the wall??? Thanks

Please reread the previous reply. Exposed foamboard is ok as long as your

house never catches fire, hence the reason most codes require the drywall

covering.