Anyone ever done this? Home was built in 1890s and can feel cold gusts from floor in winter, so we imagine cold air loss in the summer. Home near Beaumont. Thoughts? Energy savings?

You could probably get the same results without losing the functionality of your crawlspace by enclosing all the crawlspace vents and insulating the inside of the walls down there. I'd be nervous about spray foaming the space between the joists in case moisture wound up in there, and some of your drafts may be coming into the crawlspace and into the exterior walls.

There is already batt insulation in place between floor joists. No noticeable difference. Close off all vents in winter and floors are still freezing and drafty.

The fear of moisture always makes me laugh - there is already moisture there, and a properly applied spray foam is going to bond to the joists and floor deck in such a manner that you won't get moisture buildup (and if you do, it is going to be minimal).

Odds are your batt insulation is no longer effective because it has been saturated with moisture to a degree that it does not do a good job preventing heat transfer. Batt insulation is not well suited for areas like under a floor deck (exposed) in a high moisture environment (such as under the floor of a pier and beam home in Beaumont, TX).

A closed cell spray foam will do a good job, though the expense is probably going to be pretty significant getting it installed.

There are probably better alternatives cost wise, but I'm not really sure what all they would be to be honest.

I meant moisture as in, if a pipe breaks or toilet overflows, water goes down into the subfloor but can't exit down past the bottom of the joists because it's sealed off by foam. I agree that the batt insulation might be no good anyway due to condensation. That's why a compromise may be to seal and insulate around the bottom of the crawlspace, then dehumidify that area.

Ahh, different type of "moisture".

I would think that worst case, and assuming a good foam installation, that your subfloor gets wet in the event of any leaks, but that would be it. In that case you do what you are going to do regardless - mop up standing water and get air moving on the subfloor to wick out and dry the moisture. It may take a little longer if you have an adhered foam on the underside, but really it shouldn't be much or any appreciable amount of time.

Sealing off the skirting is a great start, but you'll never de-humidify the ground beneath the house. Not in Beaumont anyway. You'd have to install some type of heating system for the subgrade below the house for that to become a remote possibility, and then you are talking about beaucoup dinero.

Sealing off the underside of the house from air infiltration (or at least freely moving air) is probably the cheapest and fastest route. Keep the air from flowing under the house and you can probably reduce the freezing floors in the winter and cooling loss in the summer significantly.

Bump. Any others with experience?

I own a spray foam insulation co. Open cell would be your best choice as long as you're not very close to a body of water. Also, made sure rain water doesn't pond under house.

Ovalo, cost?

$1.25-$1.75

Care to expound on why open cell and not closed? What is your location?

It's not waterproof. You could have a rot or mildew issue should you have a leak inside your home if you used closed cell foam.

It's not waterproof. You could have a rot or mildew issue should you have a leak inside your home if you used closed cell foam.

It's not waterproof. You could have a rot or mildew issue should you have a leak inside your home if you used closed cell foam.

I wanted to spray underneath our kitchen where we just had some new wood floors installed.

The installer/flooring person told me he put a felt pad underneath, but no moisture barrier. In talking with friends, they told me a moisture barrier would be pointless because of all the nails that would eventually be driven through.

I've seen some online foam kits but they are $750-$850. Anything out there for something smaller, like 100-125 sq feet?