# Butt Rigid Insulation to Window??



## Opus X (Apr 5, 2006)

We are in the process of renovating an 1850's School house and I am a little perplexed.

I have just replaced all the windows and are in the process of ripping off all of the old Aluminum and Cedar Shake siding on the building (Cedar was underneath). Anyway, when we installed the windows we put a 3/4 inch ferring strip underneath the window flange to bring the window out slightly. This was done because we are installing 3/4 in rigid insulation to the house as well as extra thick Cedar Shakes and did not want the window to look like it was sitting in a "hole". The windows will be flashed with Vycor and capped with a drip edge and a 1x4 board will be used to "frame" the windows. The house will be wrapped in Weathertrek.

Should I bring the Rigid insulation over the flange of the window and frame on top of that or should I frame the windows first, cap and butt the foam up to the frame? If I do this I will have to stack two 1x4's for depth.

Any advice would be appreciated.

Mark


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## Square Eye (Apr 5, 2006)

Typically, the flange goes on the outside of the foam insulation.  ? 

What is the effect that you are trying to accomplish?

It seems to me that the windows are going to appear to be set pretty deep if you stack 3/4 insulation and 1x4s, OR, 2 1x4s.

Are you trying to get the windows flush to the surface of the trim, or trying to attach the trim to the face of the window instead of butting against the sides?

Tom in KY, kind of perplexed too.


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## Opus X (Apr 5, 2006)

Square Eye said:
			
		

> Typically, the flange goes on the outside of the foam insulation.  ?
> 
> What is the effect that you are trying to accomplish?
> 
> ...



We used a 3/4 in ferring strip to bring the windows off the wall so that they do not appear so deep. Meaning that beacuse we were installing the foam board and the extra thick shakes we wanted the window to appear close to flush to the surface trim. I just do not know whether to use the 3/4" foam under the 1x4 trim (this would bring the trim out that xtra 3/4" or should I install the trim and Butt the foam to it. If I do the latter, I may need two boards to make up the depth.

Sorry if I am not explaining this correctly.

I appreciate your response.

mark


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## Opus X (Apr 5, 2006)

Sorry Dupe


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## Square Eye (Apr 5, 2006)

Ahhhh, 

Well, I don't see a problem with putting the trim over the foam. If this were _structural_, you would already know not to frame with foam between members. The load of the nails or trim screws in the trim will not cause problems with the foam. The area of the trim boards will speread the load sufficiently as to not crush the foam.

As for twisting of the trim? The foam board will not offer as much rigidity behind the trim. Just the same, a trim board on top of a trim board, is likely to be affected by the bottom board and may pop loose from the twist of the board underneath. You will be fine with the foam, caulk the trim well on the sides and top. I personally am not so picky about the bottoms, because I feel that water needs to escape somewhere. It wouldn't hurt to caulk the foam to the window all the way around.

I'm sure that there are other opinions on the caulking and on your original question. I'm interested in them also.

Tom in KY, just one soldier in the raging war against perplexion.


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## Opus X (Apr 5, 2006)

Square Eye said:
			
		

> Ahhhh,
> 
> Well, I don't see a problem with putting the trim over the foam. If this were _structural_, you would already know not to frame with foam between members. The load of the nails or trim screws in the trim will not cause problems with the foam. The area of the trim boards will speread the load sufficiently as to not crush the foam.
> 
> ...



Thanks Tom, I appreciate the advice.


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