crawl space insulation
 

crawl space floor joist should i use unfaced R19 isulation and then plastic or no plastic or something eles?

Crawl space
 

Yes, use plastic. Use a 6 ml (fairly heavy duty), thinner won't hold up.

if you use batt insulation I have used 6 mill plastic.

A lot of people in our area are moving towards the spray foam insulation. Do not no to much about it but might be something others can comment on and something you may want to use.

The latest, and the science behind it: http://www.buildingscience.com/docum...n-crawlspaces/

Be safe, Gary

In my area (Canada) we do not insulate the floor, we insulate and seal the outside walls and make the crawlspace part of the conditioned envelope.
My place was built with vents, but these have been closed for many years.

The above link is very informative!

" The easy answer is to construct a conditioned crawlspace . Construct it like a “mini-basement.”

Dirt floor ?
If so you need a vapor barrier over the dirt too
My last house had both....perimeter insulation & floor insulation
Vapor barrier on the dirt

House stayed warmer, crawl space stayed well above freezing

Hey, don't blame me, Wildie brought it up........ Location, location, location:
http://www.fpl.fs.fed.us/documnts/te...entilation.pdf

A surprise with ducts in the crawl: (find the surprise!) http://www.advancedenergy.org/buildi...l%20Spaces.pdf

Foam on the walls: If you go conditioned, need air exhaust or inlet/outlet: http://www2.iccsafe.org/cs/committee...E_06_64_07.pdf

Don’t melt the permafrost, and the benefits of a conditioned crawl: http://www.eere.energy.gov/buildings...s/db/35379.pdf

If you go conditioned, take care of the radon: http://energy.cr.usgs.gov/radon/rnus.html

Be safe, Gary