I just bought a house that the previous owner started to remodel. The house was insulated with about 3 inches of Icynene Foam in the walls and the ceilling. A friend of mine who is a builder tells me it is not enough.
He recommends the following :
remove the vinyl siding and install 2 inches od EPS foam to bring the wall R value to an R 20 and then reinstall the siding.
add 10 inches of dense pack cellulose in the ceilling. The ceilling is not vented.
Is that over kill?
Will I have problems with Condensation?
I read a lot of post on this forum and I am consused.
Any help is greately appreciated.
David
Replies
I would try and get as close to R-38 in the ceiling as possible. 10" of insulation in some parts of the country could still condensate. Where do you live?
R-19 to R- 21 in the walls is also what I would try an achieve. Since you have vinyl on your house I thing it would be fairly easy to take off and put back on. Thats one of the benefits of vinyl siding.
Good Luck, Dave
I don't see what part of the couhjntry you are in.That has a big bearing on your insulations methods and condensation control. Gotta know where you are before I can give you directions how to get where you want to go.
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
I live in Western Pa about 25 miles North East of Pittsburgh
OK, For a northern heatiung climate, you are better off putting foam insulation on the inside of the studs breaking the thermal barrier and acting as a VB at the same time.
Corbond urethene spray foam insulation has studies showing that with a properly sealed house, a lower R-factor can do you at least as well as a higher with batts etc.. But that depends on sealing against infiltration in the whole house, sills to top, which is harder with a remo than a new one and you don't mention below the walls, etc.
Also, the Icy is not quite as good r-value as the urethene and not a vb as the urethene is, yet they seem lately to be making the same claims in the middle of the country without backing it up like Corbond does. I would be percectly happy with a Corbonded house at three inches, though we ar more prone to do two inches walls and four ceiling.
My suggestion for you would be to leave the walls as they are and add plenty of celluloseor chopped fibreglas in the ceiling above the Icy, and try to be sure the basement or sills are sealed against infiltration. If they were any good, they did it and you just haven't mentioned it in your verbal frugality.
I suppose if you really felt like you want more in the walls, I would put an inch or half inch of Thermax type foil faced foam on the inside of the studs and sheetrock over it. No good reason to go through so much to put it on the outside and a few good reasons not to.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
My suggestion for you would be to leave the walls as they are and add plenty of celluloseor chopped fibreglas in the ceiling above the Icy,
the icynene was sprayed on the roof decking not sure i can put insulation on top of it
Sorry, I had the impression the Icy was in the ceiling instead of the roof. Since it is a falt roof above, you can't vent anyway and don't need to vent if you insulate well enough to eliminate dewpoint condensation and use a vaporbar
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Sorry about the misunderstanding it is not a flat roof it is a cathedral ceilling. So what is the best way to proceed. It about 3 inches of Icynene enough or should I add insulation. If I do add insulation was is the best way to proceed.
[QUOTE]
Sorry about the misunderstanding it is not a flat roof it is a cathedral ceilling. So what is the best way to proceed. It about 3 inches of Icynene enough or should I add insulation. If I do add insulation was is the best way to proceed.
Not clear what your precise situation. Is it a pure cathedral (just inches of space between roof and ceiling) or do you have scissor trusses? Is the icy on top of the ceiling or the bottom of the roof?
I have scissor trusses and the Icynene is on the decking
In western PA, if I'm envisioning the climate about right, you need more ceiling insulation, roof venting, and probably some attention to the walls to seal air leaks. Adding more wall insulation, while it would be nice in theory, would be a major undertaking and, if not done exactly right, could cause rot problems down the road.
The best choice for add-in ceiling insulation is generally cellulose -- unlike fiberglass it's effective without a draft barrier on the back side. And it's cheap and relatively easy to work with.
Where do you live? If it's, say, Tennessee then what you have is fine. If it's Minnesota then you need some more ceiling insulation at least, and some attention to venting.