crawlspace insulation questions

[Mr T]

I am (finally!) getting ready to insulate my crawlspace. time for 20 questions.

Currently I have bare walls. There is a vapor barrier on the ground with several inches of gravel, sand, what looks like crushed limestone, and I think even some dirt in places. They just threw whatever they had on it.
Over the years people have done alot of work down there and torn up the vapor barrier in places. I need to replace it.

What should I do about the existing vapor barrier? THe house is too big and It is too far buried to pull up without making a major project of it. First off, other then it taking forever to dry out when it floods, should there be 1-3" of gravel/whatever on the vapor barrier? Ive dug down a few places and got to it, so I know its there. Will putting a new barrier down ontop of the existing barrier/gravel cause any problems since theres nothing to be damaged between the barriers? It's torn up in several places so moisture can get around the lower barrier.

I plan on using the pink foam board (R10) on teh walls. . Any issues with that I need to be aware of (like bug problems)? My crawlspace borders on 1 wall, another large unheated room attached to the house that is on a slab. Do I need to insulate that wall?

Thanks

[Wgoodrich]

Sorry for the late reply. I just found the post.

Your styrofoam board on the inside of the outside perimeter foundation is normal and required per IRC rules. You will be fine. The gravel may be pea gravel to crushed stone the rules don't care. Hard on the knees of the subs if other than pea gravel though.

The vapor barrier, I would not install a second vapor barrier trapping moisture between the two not a good idea. My best advice is to find the damaged areas and scrap back the gravel in the damage area and lay the vapor barrier back in place then place a new sheet of plastic just over that damaged area.

Just my opinion

Wg