I cant get a straight answer about spray foam. everyones got a different, theory......
we've only had 2 jobs that we have done spray foamed, one just being the ceiling of an old farm house. now I'm getting ready for the insulation of my own home that I'm renovating (2x4 walls, 3x6 ceiling joists upstairs, new 2x10 rafters). Now the company we have used at work the two times says to do a closed cell in the walls and ceiling. Now my neighbor who is some sort of energy star rep says that it will make the house too tight, and he thinks that doing open cell in the walls and ceiling will help with the house breathing, and even though its about r-14 for the walls (4"@r3.5) and r21 in the upstairs ceiling, that the open cell foam is a true r-rating, meaning when they say r13 for example for 2x4 batt insulation, on average it gets a much lower actual r rating, so the true r14 is much better than the fiberglass and a fraction of the cost for the open cell compared to the closed and lets the house breath better. Now my HVAC friend tells me I should do a closed cell in the walls, and an open cell in the rafters and the ceiling joists, or just the rafters alone. I know making the attic part of the insulated space can be good if you have air handlers, ect in the attic, but all I have up there is a 4' length of 14" flex going to a ceiling return grill, all other ducts and handlers are in conditioned space.
So I figured I'd throw this out there and see how many different responses I get and go with the majority vote:blink:
we've only had 2 jobs that we have done spray foamed, one just being the ceiling of an old farm house. now I'm getting ready for the insulation of my own home that I'm renovating (2x4 walls, 3x6 ceiling joists upstairs, new 2x10 rafters). Now the company we have used at work the two times says to do a closed cell in the walls and ceiling. Now my neighbor who is some sort of energy star rep says that it will make the house too tight, and he thinks that doing open cell in the walls and ceiling will help with the house breathing, and even though its about r-14 for the walls (4"@r3.5) and r21 in the upstairs ceiling, that the open cell foam is a true r-rating, meaning when they say r13 for example for 2x4 batt insulation, on average it gets a much lower actual r rating, so the true r14 is much better than the fiberglass and a fraction of the cost for the open cell compared to the closed and lets the house breath better. Now my HVAC friend tells me I should do a closed cell in the walls, and an open cell in the rafters and the ceiling joists, or just the rafters alone. I know making the attic part of the insulated space can be good if you have air handlers, ect in the attic, but all I have up there is a 4' length of 14" flex going to a ceiling return grill, all other ducts and handlers are in conditioned space.
So I figured I'd throw this out there and see how many different responses I get and go with the majority vote:blink: