I think I've read just about everything I can find on crawlspaces, but I have one outstanding question that I have heard two different answers to:

The crawlspace does not have any vents, and is open to the basement through a small door. It is a dirt floor, and block walls. What I am planning on doing is putting solid foam insulation boards up on the block walls, and vapour barrier over the dirt floor. My question is, should the plastic be extended up the walls to the bottom of the floor joices as well? Also, how should the rigid insulation be attached to the block walls?

Thanks!

There are a couple questions I would ask yet before continueing. First having to do with the usual dampness of the crawlspace. If the crawl is wet, then I would not run the plastic clear up to the sill board/joists. I would be concerned that the humidity could be wicked up to the wood causing rot issues later. Whatever the case, I would cover the floor with plastic, but only go a few inches up the wall. Also, there are glues made especially to glue foam up to cement. Just make sure that the foam you are using is compatable with the glue.

Now that I've emptied out all the junk that the previous owner left down there, the crawlspace isn't overly damp (no standing water/mold). Since the insulation is being glued onto the concrete block walls, should the vapour barrier extend to the top of the insulation, and not come into contact with the joices above?