GreatStuff for insulating floor?

[Finlander]

Had an idea of using GreatStuff can filler foam for insulating the bottom side of the floor in my wheel house. My plan was to use clear 5mil poly and attach it to the frame the popping a small hole to insert the tube to see all the foam fill in the void. Does sound too far fetched or not?

[low277]

I am not sure how much coverage you can get out of a can? It might take 50 - 100 cans to cover the bottom of a 6.5 x 14 frame a inch to two thick? Price per can? 3, 4 , 5....dollars each?

Maybe someone has tried it. I have seen a thread where someone used great stuff in addition to foam sheets on their floor.

[fishwater]

Places like FarmTek and NorthernTool sell kits for do-it-yourself spray foam jobs. They have various expansion rates and sizing for different projects. Likely be cheaper than buying a bunch of small cans?

[broman]

BASF in Plymouth will sell you spray foam kits. I bought one around 5 years ago and did the walls of my house. Cost per kit was over $500.

If you're looking to save money, do as the others say and buy the panels. Then spay foam the gaps. Cheaper, and easier. Some good adhesive will keep the panels attached.

[Lip_Ripper Guy]

GreatStuff is an open cell foam and will break down very quickly. You want closed cell. You should be able to get a pro to do it for ~$300.

[hovermn]

As LIP said, Great stuff is an open cell foam. Not only will it break down over time, it will also absorb water, weighing down your house, rotting your floor and rusting your frame. There are better options out there.

[pureinsanity]

Not only what others said, It would most likely just be a big mess and push the poly off your frame. Have a pro do it.

[low277]

According to the Dow Building Solutions page, Great Stuff is a closed cell polyurethane foam.

Apparently there are many manufactures of spray foam in a can, you have to do your homework.

[Lip_Ripper Guy]

You are correct....it IS closed cell according to their HSOforum.

If you've ever seen the closed cell that the pros use, the Great Stuff is MUCH different (softer). The good closed cell insulation dries rock hard.

[McGurk]

IMHO there has to be an easier to buy, easier to apply, less messy, and no more expensive option. I don't think you will be happy with the results, either. That stuff will push out your poly liner and make more work for you later after the expansion stops 2 weeks after you apply it. Let alone actually squirting 80 cans of that stuff, one by one, might change your opinion as to exactly how "great" it is after all. Small hole filling applications, yes. Large insulating jobs, not so much.

[tsande00]

I agree with others. I've used that stuff before on small applications and the amount it expands after spraying is absolutely unbelievable. I'd explore other options if it were my house.

[low277]

Where I live there are very few professional spray foam contractors so the price is pretty steep, along with long travel times to get to them.

I had planned on gluing in 1 - 2 inch blue/yellow foam panels as tightly as possible under the floor between the frame crossmembers and fill any small cracks with great stuff.

I have seen at least one thread where someone did this, Does anyone know how well this turned out?

[Glockwinger]

Where I live there are very few professional spray foam contractors so the price is pretty steep, along with long travel times to get to them.

I had planned on gluing in 1 - 2 inch blue/yellow foam panels as tightly as possible under the floor between the frame crossmembers and fill any small cracks with great stuff.

I have seen at least one thread where someone did this, Does anyone know how well this turned out?

I have been thinking about doing this as well with the pink foam panels from one of the home improvement stores. I would worry about the foam blowing off as I drove down the road. I too would like to know if anyone did this and the level of results.

[crappiebuster]

We used 1 1/2in pink foam in the floor of ours and cap nailed it. Just cut it tight in between the frame points and you will be pleasently suprised.

[Finlander]

Thanx everybody for this great advise! Looks like glueing in pink insulation underneath is the way to go, plus using great stuff to fill in any gaps!

[JumpStart73]

I also did the 1 1/2" pink. worked really really well.

[Mid-Lake Rock]

Have you considered doing a sandwich floor? One layer of treated plywood on the frame, a layer of pink insulation and another layer of plywood. I did this on my house and the floor doesn't get cold at all.

[JeffB]

If you factor in the materials used for a sandwich floor and the extra weight the having someone spray foam the fish house was an easy choice for me. I had the floor, walls and ceiling done on my 8x17 for $600. It really makes for a strong and warm house. I didn't put any sheeting on the inside so this also saved time, money, and weight. You can paint the foam with a latex paint and it holds your wiring in place so you wont have wires wearing from the bouncing.