On Sep 20, 11:04*pm, " wrote:
On Sep 20, 7:49 pm, wrldruler wrote:





Converting 300 sq ft garage into family room. Installing full floor
above garage concrete slab. I want to put a polyethylene vapor barrier
on the concrete.

Most places I read recommend 6 mil polyethylene. Home Depot selling
for $50.

When cleaning out the garage I found a brand new box of 4 mil
polyethylene that my Dad had given me.

Would it be a problem if I used the 4 mil that I have, instead of
buying 6 mil?

I have a giant box. Can I double-up the 4 mil, creating a 8 mil
barrier?

Thanks,

Chris

might be ok if all seams sealed and overlapped. but plastic isnt
forever. how old is it?

if your getting a permit run it by the local code enforcement building
inspector- Hide quoted text -

- Show quoted text -

Prob Ok if never exposed to sunlight!
But 300sq ft. of 6 mil not very expensive? Assuming you have to
insulate and vapour barrier the walls (unless they are already
insulated and vapour barriered) use the 4 mil for that? Also what
about the ceiling insulation and vapour barrier for a room that will
now be heated, occupied by living breathing people and other
activities that put out moisture; is that insulated and vapour
barriered?