A vapour barrier under the subfloor or laminate will trap moisture. A vapour barrier under the floor will not stop condensation on the ceiling of the crawlspace and movement of the moisture into the floor above. Converting the crawlspace into a conditioned space will avoid moisture problems. Here is a link that might be useful: Conditioned Crawlspace Construction

Great comments everyone...price ...can be between $2- $3/sf. Anything more is overkill. As to the smell of some companies poly ... there was a run 4+ years ago where a handful of manufacturers that made a poly that was white on one side and black on the other and was reinforced. 1 of 10 after several months to a year started smelling like cat pee and got stronger. I ripped out a handful of these crawl poly's. I wouldn't blame the sealed company's only because we all look for a deal on plastic to pass on to you ... and the odor doesn't start for awhile...that could be 400 crawls in 6 months for a handful of us. That's 40 of them stinking and 30 notice enough. About the DIY'ers ... I have DIY hardwood floors ... brakes... toilets...etc ... It takes me 6 months to get a diligent guy up and going on crawls where I can let him run and inspect his work after. I couldn't imagine the $ lessons learned that a DIY'er gets into. Just know it takes one really experienced crawl space tech and 3 new techs to finish correctly a 2600 sf sealed crawl using 50 labor hours. Know that 50% of your homes air comes from the crawl space so a poorly prepped sealed crawl can trap some pretty nasty mold. Dehu's: to use or not to use??? Tests show that mold has not grown in sealed crawls that use a 4 inch air supply line per 1500sf with average height of 2.5 ft. Though the humidity reduces down in the South (Raleigh Area) to 68%-77% when sealed still leaves high humidity compared to the average homes humidity of 52%. But mold does not grow. Why? I can only guess ... A. Ground, where mold comes from, is sealed off B. Air is slightly circulating from the air supply line on your supply side. And a dehu wholesales $1000 average ... then install and electrical hardwire hookup and gravity fed condensation line. $1600-$1800 should be fair?? And that will take your humidity down to your chosen level ... most, I have found, chose 50%. Now here's the rub ... your dehu is taking up a chunk if not all of your energy efficiency that your conditioned sealed crawl gives to your AC system. So if you don't take the old insulation out and seal in the mold and the defication from the crickets, mice and snakes and you aren't getting any efficiency out of the sealed crawl ... then why invest $ at all??? No savings or better air quality. My recco: pull floor insulation, sanitize entire crawl for SUPERIOR lifetime air quality ... seal crawl and forget the dehu and gain 15.8% energy efficiency on new homes past 2008 ... higher efficiency for older homes. My pet peeve.... if a home has mold on the beams and evidence of cricket poop ... little black pellets all over the joists ... I wont seal it without pulling the insulation and disinfecting the crawl. But 95% of all companies seal the crawl trapping in ALL THAT MESS and that's there standard seal crawl practice. That should be criminal!!! Like all the contractors who knew back in early 1900's that lead based paint was killing children but kept using it because it was cheap ... until 1970's when a law was passed after ??? more than a million baby's past away. I feel mold in the crawl is that same issue that is slow to REAR ITS UGLY HEAD ... buyer beware ... short cuts can hurt you long term. www.SealedSolution.com

I cant really answer your question but i had an estimate to have the cleanspace installed and they wanted nearly $8000 dollars and my house is not even woth 60 thousand so i passed. Why did they paint? And i did not know that the liner had an odor. The man told me that if i had the liner installed that and mold growth in the crawlspace would stop. i have a very small amount of mold down there. Sorry to hear that you are have issues with the smell. Did you ask the installer about it?

Grade the dirt to get it level, put a minimum of 6mil poly over the dirt and glue it to the perimeter the best you can. If you want and I would bring in rock to place over the poly to protect it or you could pour concrete over it. As far as the walls and floor, I would spray foam the walls, and have a company blow in insulation in the floor. I would then attach foil faced foam over it and tape the seams.