I have always over spec'd my projects and this crawlspace is no exception. 1940's house (girlfriend's family house since new), replace damaged seal plates, floor joist,bottom plates, studs and sheathing due to saturated crawlspace. Did all the preventative work first of installing drains around the house. This eliminated the standing water every spring.
Now the crawlspace. 38", workable head space. vac,d out the cobwebs, restrapped and lifted duct work, removed old nails and piping, wired 5 lights and some plugs, sifted dirt for debris and leveled. This whole time my girlfriend is saying, "Can't you just lay some visquin down and a string of lights! You always have to take it to the moon, don't yea!" Now remember this is her house, my time, my aching knees.
I only took the 12mil utility to the blocks up 6 inches. Attached the 12mil border using the pins thru vinyl siding starter strips and block, caulking the 12mil to the strip creating more tug support(remember now, this is going to the moon) and laying a bead at the strip/vinyl/block line. Then I had it foamed 1" thick up into the end plates/floor joist. This gave me my vapor barrier and some insulation.
Plastic pins are strong and permanent. Caulk empties to fast, bigger(I used 10 tubes). The tape was only used on 12 mil surface and it was good. The 12mil? Way past my expectations. No need for the 20mil, unless your going to use it for car garage utility space. You can't tear the stuff. Had to use a hammer to punch a 3/8 lag bolt thru. Cut it with sizzors(slicing it), not with knife.
I did purchase the dehumidifier and ran it prior to the project. Just to much for it to handle(a great unit). It's still hanging in there, but it doesn't have much to do.
Well the projects done, and yes it's like walking on the moon, only cleaner. I prefer socks over moon boots.
Never been to Jupiter. Wonder what Jupiter looks like?