Spray Foam Ad Nauseum

[btuser]

I've got about 800 sqft under my garage I want to spray foam. 3-4" with closed cell foam to about an r30. Reason I've decided on sprayfoam is the floor above the garage is dimensional oak. I'm hoping between the vapor barrier, added insulation and sticky foam I can quiet down some of the squeaks. Right now its only an r11 with 1/2" standard drywall and a popcorn ceiling texture. I'm going to do some plumbing, electric, and if I'm going to trash the ceiling anyhow I'd rather just re-do what shouldn't have been done before.

So question is this: I'm in the Northeast and have heard quotes of $.75-$2.00/bf for closed cell insulation. I'm getting some quotes but is sure seems like its not worth it to get a sprayfoam kit and tak a stab at it myself. Anybody have luck with the kits?

 

[Wallyworld]

Aren't the kits just as expensive? My understanding is a good pro will do a far better job than you would with a kit and the price isn't much different.

 

[btuser]

yeah that's why I've heard

 

[midwestcoast]

I've looked at the DIY kits too (Tigerfoam & another that I forget), and came to the conclusion that I'd come out ahead by hiring a pro, even on a smaller job than yours, since the kits are so pricey & I prob would not use it as efficiently as a pro..

 

[btuser]

After a couple of hours looking around it seems there's just not the profit margin to do it yourself. Maybe if there was either a lot or a little, but not anything between 100bf and 10,000 bf. As far as I can tell just the cost of the material is around $.50/bf, which compared to either fiberglass or blown-in which is closer to $.05-.10/bf, so for my job material cost alone would be about $1500-$2000 and the best price I've seen on an internet kit is arould $3,000.

Hmmm, Maybe if I buy the spray set-up........

 

[Wallyworld]

Not sure what the space you want insulated looks like, but I built a new addition on my house, 16 by 24, 2by6, flat ceiling, attic space. I cut and fit foam to the studs, full 5 1/2 inches, using seconds foam. I either caulked or used home depot canned foam to seal the edges or cracks from my cuts. Wasn't easy or fun but it was cheap. I have no heat in there other then what comes in from the door or basement and it stays warm.

 

[begreen]

The real question is, will spray foam solve the original problem of a squeaky floor? Usually this noise is due to wood travel. Maybe the floor needs better screwing down to the supporting joists before foaming?

 

[btuser]

That's part of the plan. Its plain sawn oak strip on top of 1/2" osb (yeah, I know) nailed down to 2x8 joists over an un-heated garage. Ideally I would have used an engineered floor or at the very least 1/4 sawn but I'm stuck with what was here when we moved in. My plan is to create a thermal barrier to cut down on wood movement.

 

[begreen]

Oy. What were they thinking by not putting down a proper underlayment? That's not the place to cut corners. Regardless, it's hard to beat a continuous layer of sprayed foam for blocking air infiltration. I'll be curious to find out if the foam helps mitigate the squeaks too. Keep us posted.

 

[woodsman23]

1/2" Is not going to cut it. You must have at the least 5/8" plywood or osb but 3/4 to1" is best. Is there someway to remove the flooring and add (with glue) 3/4" plywood or osb??. To get rid of squeaks add shim stock to where ever the squeaks are, have someone stand on squeak and locate in garage cieling and tap a shim there with some glue on it to secure, tap until squeak goes away.

 

[TMonter]

Most floor squeaks are because the floors were nailed and not screwed. Using good quality screws will usually take most of the squeak out.

 

[btuser]

1/2" Is not going to cut it. You must have at the least 5/8" plywood or osb but 3/4 to1" is best. Is there someway to remove the flooring and add (with glue) 3/4" plywood or osb??. To get rid of squeaks add shim stock to where ever the squeaks are, have someone stand on squeak and locate in garage cieling and tap a shim there with some glue on it to secure, tap until squeak goes away.

I'd live with the squeaks before I removed/reinstalled 800 sqft of hardwood. Anyway, I'm not in the game if the project is over 2 grand. Payback for the added insulation is already at 20+yrs! I think its a combination of no screws on the subfloor (I can't confirm this but I'm pretty certain) and the cold garage against the bottom of the flooring and the heated space above. I think a nice thick 4" of 2lb foam would keep it quiet.

 

[begreen]

Well, you probably won't hear the Cummins diesel pulling in the garage afterward. %-P

 

[btuser]

Well, you probably won't hear the Cummins diesel pulling in the garage afterward. %-P

Actually, its a Duramax, but she gets left outside because she's too big! I should have measured before I bought the house.