Insulation ?

[naturalgas]

I was just quoted $5500 to spray foam open cell my 36x40 garage is open cell an ok product to use?

 

[manwithtools]

Two points to consider with open cell:
1) It does not offer any vapor barrier resistance, so if you don't have house wrap over your OSB that could be a concern.
2) It is fairly flammable, so you will need and inside wall and ceiling cover (drywall, metal, etc.)

Otherwise, yes it can be very effective product to use.

 

[naturalgas]

Two points to consider with open cell:
1) It does not offer any vapor barrier resistance, so if you don't have house wrap over your OSB that could be a concern.
2) It is fairly flammable, so you will need and inside wall and ceiling cover (drywall, metal, etc.)

Otherwise, yes it can be very effective product to use.

Thanks, this is a rebuild The original burnt down 15 months ago. Im too paranoid of fire now to even consider it. I didn’t think of flammability. I’ll be going with fiberglass.

 

[manwithtools]

Rock wool is even better than fiberglass when to comes to flammability.

 

[Firebrick43]

I could see foam in the walls, but you have a conventional ceiling.

Foam will be a waste of money over the proper depth of blow in cellulose there.

Rockwool and wet blown cellulose will be superior in the walls compared to foam in fire resistance

 

[PCustoms]

What thickness/r value was the quote for?

 

[Hank11]

I did open cell foam under the roof deck - 7” or greater. The walls are fiberglass. Its worked out well. You can add a fire resistant coating to the foam if you want. I did not as its not exposed.

 

[billconner]

Rock wool is even better than fiberglass when to comes to flammability.

Testing at Oak Ridge National Lab showed cellulose was even better.

 

[NUTTSGT]

Testing at Oak Ridge National Lab showed cellulose was even better.

Lab tests are different than real life.

 

[Stick-man]

Just for reference, I had my 35x43 sprayed with 1" of closed cell, walls and roof, for $5200

 

[billconner]

Lab tests are different than real life.

Yeah. In real life batt's reform much worse than their rating.

 

[racecougar]

I could see foam in the walls, but you have a conventional ceiling.

Foam will be a waste of money over the proper depth of blow in cellulose there.

Rockwool and wet blown cellulose will be superior in the walls compared to foam in fire resistance

Agreed. It looks like a conventional ceiling with vented soffits and ridge. That is a perfect candidate for blown insulation (cellulose or fiberglass).

 

[NUTTSGT]

Yeah. In real life batt's reform much worse than their rating.

and cellulose smolders causing wood framing to burn.

 

[billconner]

Cellulose insulation has a class 1 fire rating and because it's denser than fiberglass or Rockwood, it burns slower and in a wall, lasts longer.

 

[Firebrick43]

and cellulose smolders causing wood framing to burn.

Fire causes framing to burn. Cellulose does not spontaneously combust. Rockwool or fiberglass is not the cause of fires either. Foam can spontaneously combust during installation if applied too thick too fast.

The density of cellulose limits oxygen and borates (flame retardants) do tend to make cellulose smolder instead of having very little resistance to air flow like fiberglass, which allows for chimney effect to take place in stud bays. Once air flow is established, it only accelerates the speed and intensity of the fire.

Yes, it takes longer for fire fighters to snuff out all the smoldering hot spots in a building with cellulose but it more importantly adds precious minutes to allow the occupants to escape the building.

 

[acer66]

Rock wool is even better than fiberglass when to comes to flammability.

Pretty good handling moisture too and rodents do not like it either.

 

[naturalgas]

So I’ve decided on passing on the foam. I’m going to have blown in cellulose for the ceiling and fiberglass for walls. I’m thinking paper faced for the walls versus poly covered bare batts. Is paper faced just as good as poly covered? Same price for either.

 

[billconner]

I believe a continuous piece of poly - like wall height and width - is a better air barrier than the kraft paper on batt's.

Neither should be left exposed. Wasn't clear if that's what you were suggesting.