Spray foam insulation under floors

[Axial]

Are there any gotchas to be careful of in having spray foam insulation, e.g. GacoGreen or similar "2 lb" quality, under the floors in a home w/ crawlspace?

40-yr-old house in Pac.NW, rancher, 3 "levels" dropping approx. 4 ft each time due to hill location, approx. 4ft high in most places. 16" o.c. joists. Dirt crawlspace, very clayey soil, had ground moisture (not wet, but close to it) but now with added vents, two layers of vapor barrier on ground in winter, but pulled back and fans blasting in summer, it's getting dried out. Mostly hardwood floors, and they're cold in winter.

When I renovate kitchen/bathrooms the plumbing will change, but in both cases I want to put in radiant floor heating so I might do fiberglass just in those areas.

Because of the moisture I'm leery of doing fiberglass, and from what I have read in my research, the spray foam seems like it might be a better solution from both moisture and sealing air leaks. But are there any gotchas I should be considering?

I appreciate any comments.

[maradcliff]

Be sure you dont fill the whole crawlspace or basement......

This might sound like a joke, but I know someone that rented one of those cellulose pumping machines. They stuck it in the wall, and started it. After dumping in some 30 bags, they bought more bags and kept pumping it in. That's when I came on the scene, and they were cussing because those 30 bags were supposed to do the whole house, and they were still in the original (first) hole, and nearly 50 bags later. I walked into the house, saw a dust storm, and was shocked when I got in the basement. That whole corner of the basement was nearly to the ceiling because of an opening in the sill from an old heat duct.

That required a whole day of filling trash cans and pouring it back in the hopper.

(I resisted telling them what idiots they were, but the urge was there) !!!

Mark

[Axial]

Thx for the story. This would be done by a professional installer, so hopefully it'll be done right.