I live in Baltimore area, MD. I currently have an unconditioned crawlspace, with what is likely R13 FG falling out of the joists. HVAC is in the crawl. The ground is gravel and it can get moist; I have a sump pump down there. Short of the hurricane, it doesn't flood, but there is moisture.
Here's what I've come up with thus far:
DIY: install 10 mil vapor barrier according to recommendations here. Switch open vents to automatic opening vents (as HVAC is down there). Unless, because that system is down there, they should be left open.
CONTRACT: Sprayfoam insulation in rim joists and floor joists.
This is the part I'm looking for advice on: I have two quotes for sprayfoam. One for 2" closed cell + R19 FG in the floor joists and another for 3" closed cell, no FG. Price between them is negligible.
I've been to buildingscience.com and read up, so here's the questions:
Is it worth it to even consider the SP+FG combo?
With a good VB
, is 2" closed cell enough?
3" seems like it's just going to pretty much fill the entire joist - is the extra inch worth the money? I'm gonna put down the VB
TIA for your advice - and I've learned a lot reading related posts on this forum....