How does one get insulation between the 1/4-1/2" gap of the wood frame and
window frame when access is blocked by the nailing flange on the outside and
gyproc on the inside? I guess I could cut the gyproc back another 1/2" or so
but then I would need to fill it.
I just had 33 new windows retrofitted in my house. The manufacturer's
instructions do not specify adding insulation between the window and
the wood frame. The window frame itself is already insulated. But they
do have very explicit instructions about the use of window wrap tape to
seal the window on all four sides.
Jeld-wen does specify to add either foam or loose fill between the rough
opening and window frame. These are the most comprehensive install
instruction I have ever seen.
I've read and re-read the instructions. I have Jeld-wenn windows and
each one had a paper copy of these instructions attached (same as on
the website). I read the instrructions as going through step by step
to install the window and tape it (under section called "Install
window"). The section you referenced is called "complete instalation"
and refers to adding exterior wall surface AFTER the window is
installed and then insulating between the rough opening and the window
frame. I interpret this to mean adding insulation between the exterior
wall opening and the window frame. Please read it carefully and tell
me what you think.
Maintain gap of 1/4"-3/8" between window frame and final exterior wall
stucco, etc.) unless otherwise specified by local building codes or exterior
manufacturer; seal gap with backer rod and high quality caulk
- This is done on the outside
7 Insulate void between rough opening and window frame with loose-fill
low/minimal expansion foam sealant may be used if required by local code
This is done on the inside between the 2x4 rough frame and the SIDE of the
Here is a link to a picture of my window *temporarily* installed (yes, i
know it looks bad). The insulation needs to be pushed in the side behind the
gyproc before I complete the job.
As you can see there is very little room to get the insulation in between
the frame without cutting back the gyproc another 1/4" or so
8 Apply interior trim as desired
This makes sense because it would be the next step in finishing the inside.
I discussed these instructions with Home Depot and they agreed they were
major overkill. I'm just going to use tar paper or window wrap and a lot of
caulk instead of metal flashing and forget about the plastic drain screen as
well as side shims. Unless you live in a area with high winds and driving
rain it should not be a problem. My old windows only had tar paper and never
leaked. Most of my windows are under a 1-2' roof overhang
Here is the install guide for some other windows I was considering:
Martik AKA Rob
BTW, how do you like the windows? I think the inside finishing, especially
the corner welds, could have been better. Also the sliders only slide about
an 1/8-1/4" into the frame whereas my other NAP windows slide almost to the
end. I purchased them mainly because of the price and lifetime warranty.
I'm at home using an offline reader, so I may look like a different guy, but
I'm the same Bob or BillyBob (can't remember how I'm configured).
I like the windows a lot. I don't have anything to compare them to from
another housing experience. I live in Houston where energy efficient
windows were unheard of 3 decades ago. The windows operate smoothly, made
the house quieter and dramatically evened out the temperature in the house.
I really look forward to seeing their effect in our horrible August heat.
One thing that is really weird - they don't look all that dark to me, but
when the sun comes through them, its like the radiant energy is completely
stripped. During cooler weather, I always used to stand in front of a bank
of windows where the sun comes in and enjoy the warmth. Now I have light
coming through but no radiant heat. It freaked me out at first. and yes, I
liked the warranty.
My house is a light colored hardi-plank (newly installed) and the white
window frames look much better than we ever expected.
Your picture explains your dilemma well. I have run into this. It is a
little late now but for any future projects I will tell you how I deal with
this. Before the window is installed I apply a 1 1/4"x 3/4", one sided, foam
around the new windows jamb. This seals and insulates well. Some
manufactures will sell the windows with this already applied. I buy it by
the 50' roll at the local siding distributor.
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