Closed cell or open cell foam backer rod
user-7601308| Posted inGeneral Questionson
Do i want closed cell or open cell backer rod for the space between my window rough opening and window jambs?
同时,我的粗糙的开口有点超大号的with almost an inch on each side, and top and bottom between RO and window jamb. Is there an oversized backer rod that would be suitable?
And — do you install the rod on all 4 sides of the window? Do you push it in from the exterior or interior?
thanks,
forrest
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Replies
Forrest,
What kind of windows are you installing. Fanged? flangeless? wood with brick molding?
Non flanged wooden window frames.
Do I only put backer rod on the sill of the rough opening? And then just insulation between the sides and top?
Forrest,
As Andy said: Furring down the ROs so that you have about 3/8" makes everything much easier.
Then put the backer rod about half way towards the exterior and fill the gap with foam. You can add a bead of caulking at the interior face as further insurance.
The sill gets treated differently. It needs a sill-pan of peel & stick membrane placed in the RO before the window is installed. If the sills are not sloped it should be turned up to create a dam at the inside face of the window frame. A bead of caulking provides the air-barrier. No insulation is used.
"my rough openings are a bit oversized with almost an inch on each side, and top and bottom between RO and window jamb. Is there an oversized backer rod that would be suitable? "
An inch on each side seems a bit much. I'd be furring out that RO to be a little closer to the window size. I mean, how are these windows going to securely attach with that much of a gap? How would they be trimmed out?