Hey guys it's been a while since I've posted here,but if finally getting around to getting my garage done.It looks like my electrician should be getting started next week.Anyways my garage is technically detached even though it shares the same roof as my house.I have a breeze way that's enclosed however not heated or insulated in any way same thing goes for the garage.My question is if it's worth using rigid foam insulation like foamular 250 in the garage on the walls??Garage is framed out with 2x4s or should I use the regular fiberglass roll in insulation???I would like to make the garage as best insulated as possible as I spend a lot of time in there working.Heating and a/c will be done using a mr.cool unit.Also what is the best insulation for the ceiling??Do I need to vent it??and do I need a vapor barrier??
Insulating attached garage using rigid foam??Worth it??
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Blown72Duster
New member
I just built a new pole barn. and am using Prodex 48 it is sold by insulation for less online, it a thermal and vapor barrier in. It has foil on both sides with stapling tabs
theoldwizard1
Well-known member
From strictly an insulation value, I don't think rigid foam is much better than fiberglass.
There is one case where it would excel. If you have no house wrap, use foil faced rigid foam, with the foil face up against the outside sheathing and them used can spray foam around the edges to hold it in place. Doing a whole garage will take a long time. I would do 1" of this and then fiberglass.
There is one case where it would excel. If you have no house wrap, use foil faced rigid foam, with the foil face up against the outside sheathing and them used can spray foam around the edges to hold it in place. Doing a whole garage will take a long time. I would do 1" of this and then fiberglass.
cajunfirehawk
Well-known member
I hope you did your research on both of those
, a quick google search shows not so good reviews on both the product and the company....fwiw.Voi
Well-known member
I have used rigid foam trimmed to fit in stud bays. I got a good but not great deal on some foil faced polyiso so I went with it. I trimmed it a bit shy of a perfect fit and used canned spray foam to fill the gaps.
I do think it makes for a tighter wall than batts but am not sure it's worth it unless one gets a really good deal on the foam.
After doing it I wonder if I would have been better off using inexpensive batts in the walls and then foam over the top of the studs. Then use longer screws to attach the drywall over the foam. I think with the money saved on Great Stuff I would have been able to buy a lot of batts and I would have greatly reduced thermal bridging by having the foam over the studs. And there would have been less mess, less waste and less busy work on my part. But I'm not sure if it's possible to mount drywall over foam like that nor how much it would give me fits when trying to find studs to mount cabinets, etc.
Alas, that project is behind me so no sense wondering.
What part of the country are you in? Does the garage have trusses or rafter ties to attach a ceiling to? That will affect how the other questions are answered.
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Jon_E
Well-known member
I managed to get my hands on a couple of thousand square feet of 2" thick fiberglass-faced polyiso board (off a flat roof) and will be cutting that to width, fitting into the stud bays and foaming around it with can foam. Since the fiberglass face is not a vapor barrier, I am then going to foam over the entire board with a thin layer of DIY spray foam (like Tiger Foam) to encapsulate and provide more R-value. It's a good enough system for a garage, for me.
Blown72Duster
New member
I hope you did your research on both of those
I did do some research and there are a couple other company's that carry a similar product, I believe that the other company is eco foil. I did see several instances where there were unsatisfied customers, but I'm sure one could research and find something bad about every company out there. When my shient arivred I was short one roll and noted it on the b.o.l. and contacted the company right away and the said that they had to wait for about 10days to see if shipper could find which they did not and the filling week I had my replacement roll
It justmy experience with that company, was just giving my opinion on what I was useing I'm my pole barn.
