Current vapor barrier in crawl is about 12 years old. It seems thin, maybe 3 mils or 6 mils at best. At any rate, its shredding in several areas exposing the damp dirt underneath. I live in a heavy clay/chirt area. Soil is hard packed. I want to completely cover dirt floor and tape the seams. Couple of questions.
1) Should I rip out old or can I simply lay a new layer on top of the old. Old is secured on corners with some sort of spike and large washer nailed into packed dirt.
2) Thickest I can find is only 10 mils. Is that sufficient? Should I try to source thicker like 30 mil pool liner or is that a waste of $$?