I want to add a new window in the wall of an attached garage. The existing
garage wall has aluminum siding on the exterior and is just an open studded
wall on the interior.
Here's how I am planning on doing it and I am wondering if this is correct.
I haven't been able to find any how-to-do-it instructions or videos on the
My plan is to buy a new-construction vinyl window and cut off the nailing
fin that is normally used to nail new vinyl windows to the studs. Then
frame out the window opening and cut the existing aluminum siding flush with
the framed window opening. Then insert the window in the opening from the
exterior and secure the window to the studs with nails or screws going
through the sides of the window into the sides of the studs. The
installation would be similar to installing a prehung door into a similar
opening (which I just did in the same wall). The exterior window trim
overlap without the nailing fin would cover the aluminum siding, and then I
would caulk the aluminum siding where it is under the window trim using
clear 100% silicone caulk.
Is this how it is done?
Thanks. That was for a "replacement" window where an old window was being
replaced with a new one.
In my case, I am adding a new window where no window existed before. So I
am buying a "new construction" window, not a "replacement" window like the
one you saw on TV. But the problem is that what I am doing is also not
completely "new construction" -- it will be a new window that goes in a
previously constructed wall with the aluminum siding already in place.
Thanks. I'll definitely be doing that.
Since I haven't heard otherwise from anyone, I assume that the way I am
planning to do this is correct. It just seems strange to me that there is
nothing out there that explains how to do this. I would have thought that
even the window manufacturer's themselves would have instructions for this
on their website or somewhere.
All I can find is how to put in a replacement window, or how to install a
window in completely new construction before any siding is in place. Now
that the Internet is here, I am spoiled and I expect to be able to sit here
at my desk and find any information I want. :-)
That's not a good assumption. I'm not an expert, but I'm a bit
uncertain about the method you propose. How are you going to attach
flashing between the sides of the window and the sheathing underneath
the aluminum siding? If the aluminum siding can be easily remove and
reused like vinyl siding can, I think that would be a better approach.
I haven't figured out any way to do flashing other than to try to put it in
when the opening is cut and try to tuck it in under the existing aluminum
I've been looking at all of the YouTube.com videos on window flashing and
none of them describe this situation.
The main difference between a new window and a replacement window is
that the replacement window doesn't have the flashing. You can install
it with screws through the frame into the studs, shimming as needed.
Expanding foam in the gaps seals it up. Compare this to installing a
pre-hung door. Some window manufacturers might give you a more elegant
What you're proposing is essentially the same as a replacement window.
After you frame it in with a header and sill, then cut the hole through
the sheathing and outer finish, you're exactly where you would be if
you'd removed an old window. It'll just be neater 'cause you won't have
to futz with old caulk and casing.
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