Mounting flanged window to frame without removing siding.

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frankpc
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Location: Shawnee, Kansas

Mounting flanged window to frame without removing siding.

#1 Post by frankpc »

I am preparing to add two fixed picture windows, dual pane, vinyl, approximately 46"W x 72"H, to a house that has 7/16" Smart Panel siding. The windows have a 1 1/4" vinyl mounting flange on all four sides that is typically nailed to the wall studs.

The house has no boxing nor paper of any type between the studs and the siding. Walls are 2x4. House is in Kansas.

Rather than removing the siding, installing the windows, and re-applying the siding over the flanges, I am considering cutting the siding such that the opening is large enough to allow the windows to be secured directly to the framing, then using 1 1/4" strips of siding over the flanges (just as spacers), and then applying 1 x 4 Smart Panel molding around the windows, which would hide and overlap the strips.

Question is, how bad of a practice is that? I would, of course, use a high quality caulk to seal the 1 x 4 's to the window and siding. The existing windows on the house, have the 1 x 4 moulding. They appear to be the flange mounted type of vinyl window.

Thank you for your time.

Frank

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Windows on Washington
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Re: Mounting flanged window to frame without removing siding.

#2 Post by Windows on Washington »

You can do that.

I would just make sure that you re-install J-channel all the way around and a drip cap at the window head.

frankpc
Posts: 20
Joined: Sun Apr 22, 2012 10:53 am
Location: Shawnee, Kansas

Re: Mounting flanged window to frame without removing siding.

#3 Post by frankpc »

Windows on Washington wrote:You can do that.

I would just make sure that you re-install J-channel all the way around and a drip cap at the window head.
Thanks,

I believe the drip cap would be placed behind the siding, spacer, and 1x4 at the top and then extend out over and bend down a ~1/4" over the top front edge of the window frame.

But not sure about the J-channel. I believe that is used for perhaps a lap siding as it comes up against a window frame. In my case, the siding is flat - no overlaps. I know I wasn't clear about that. Would you elaborate a bit on J-channel requirement?

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Windows on Washington
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Re: Mounting flanged window to frame without removing siding.

#4 Post by Windows on Washington »

Yes. Not required on T-111 or other flat siding.

frankpc
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Location: Shawnee, Kansas

Re: Mounting flanged window to frame without removing siding.

#5 Post by frankpc »

Windows on Washington wrote:Yes. Not required on T-111 or other flat siding.
OK. Thanks for the advice. I'll try to move forward.

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Windows on Washington
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Re: Mounting flanged window to frame without removing siding.

#6 Post by Windows on Washington »

Be sure to flash the sills, jambs, and head with some for of membrane or metal. If you do it right, the window will not leak if the house were underwater.

frankpc
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Location: Shawnee, Kansas

Re: Mounting flanged window to frame without removing siding.

#7 Post by frankpc »

I'll do it.

I recently had to remount a 3' x 5' window on a house built at the same time and by the same builder as mine. One side of the window was 3/8" higher than the other side. This was a double hung window. So neither the top nor the bottom would keep the wind and rain out. Ridiculous! So I cut the flat siding away from the flanges to remove the nails on one side, the top, and the bottom. (5 nails total).

Anyway, the only flashing it had was at the top - a drip cap. I was wondering whether that was unusual. No boxing, no tar paper, nothing in the walls.

Thanks again.

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Re: Mounting flanged window to frame without removing siding.

#8 Post by Windows on Washington »

Might not be unusual considering the shortcuts that are taken but it isn't proper.

frankpc
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Re: Mounting flanged window to frame without removing siding.

#9 Post by frankpc »

I'm sure my dad wouldn't be happy if he heard about it. Just seems as though the house's integrity is based on the use of caulking. When the caulk cracks, water comes in. Just doesn't seem right.

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Re: Mounting flanged window to frame without removing siding.

#10 Post by Windows on Washington »

frankpc wrote:I'm sure my dad wouldn't be happy if he heard about it. Just seems as though the house's integrity is based on the use of caulking. When the caulk cracks, water comes in. Just doesn't seem right.
Welcome to the world of new construction in the last 20 years.

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