Is something missing in this gap? I had a lot of water come in through the top corner of this window last storm.

I’ve caulked and placed silicon anywhere I can see possible. The entire house siding along the right side of the window about five feet down is rotten so I’m a little confused where all the water is coming from.

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1 Answer 1


That is a very unusual installation.

The windows are made with a “flange” that is about 1 1/4” wide all the way around each window. The flange is made watertight to the window frame and is used to fasten (nail/screw) the window to the window opening.

Unfortunately, I see a few problems: 1) window flange cut off between windows, 2) no cover flange between windows, 3) lack of backer rod for sealant between windows, 4) weep hole plugged

1) The top window fits so tight to the bottom window that it appears it’s flange was trimmed off. (Hopefully, the lower window was installed first so the top window overlapped the lower window flange.) However, If the window is leaking, it wasn’t properly sealed between the two flanges.

2) Some windows are made to “fit together” in a pattern. When there are extra large openings, the window weighs too much to lift into place. So, the manufacturer makes a cover that clips into both windows to seal the space between the windows. Obviously, if this is one of those types of installations the clip has been lost.

3) It’s not the quantity of sealant but the quality of the installation. That is to say, the depth of the sealant should be about 1/8” to allow the sealant to expand and contract. The way this is accomplished is by using a backer rod. It keeps the sealant from filling up the entire space and is placed so the outside edge is about 3/16” from the face of the window.

4) It appears that the upper window’s weep hole is plugged with dirt, etc. The stops need to be removed and weep holes cleaned.

I can’t see the edges, top or bottom (sill) of the window so cannot make a determination on those issues. If they’re leaking too, (as you noted) the original installation was probably poor.

I’d recommend removing all the windows and using “peel-and-stick” paper along with new backer rod, sealant, etc.

  • I’ll edit with a couple more pictures in daylight tomorrow to give the full perspective. It sounds like you know what you’re talking about. I appreciate the info.
    – ThisClark
    May 23, 2019 at 2:48
  • Where in my first picture do you see weep holes? I would attempt to unclog it but don’t know where it is, and I don’t know what the stops are that need to be removed. I’ll go to some YouTube searches with the extra vocab you’ve given me.
    – ThisClark
    May 23, 2019 at 2:52
  • On the far left side of the upper frame you’ll notice a small dark spot. It’s in a small oval hole. It fills about half the hole. It looks like something white fills the other half of the weep hole. There should be 3-4 other holes along that part of the frame too.
    – Lee Sam
    May 23, 2019 at 3:44
  • Remember, it’s not just between the two windows. You’ll need to carefully reseal the entire perimeter of all windows. Rain water gets “pushed” uphill too when the wind blows. Make sure everything laps onto the window frames (and sealed) so no moisture gets behind the siding either.
    – Lee Sam
    May 23, 2019 at 3:47
  • Would it be sufficient sealant to put backer foam in that gap and fill the rest with silicon or does that fall in the category of bad install that causes more problems?
    – ThisClark
    May 23, 2019 at 22:07

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