Guidance on leaking double window

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fisherman
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Joined: Tue Feb 23, 2021 2:20 pm

Guidance on leaking double window

#1 Post by fisherman »

Thanks for letting me join the forum. I'm trouble shooting a leaking Alside window installed in our new construction home. Home is about 2 years old. Here's a few details:
1. Second floor double window leaks during hard wind driven rain hitting side of house/window (Vinyl siding).
2. Weep holes run clear.
3. What's the leak like? Water drips in down the drywall from under window trim (see photo). I pulled away apron/trim and water appears to come in along the length where I stuck the white paper strip. Also, internally, water has dripped down inside the wall to the first floor.
4. Neighbor who had house built at same time has same windows also experienced similar leaks in a single and double window. After trying to redo the install itself over and over, replacement windows were ordered & installed by builder and no more leak as of yet.
5. Research online suggests possible defect with mulling or pocket sill. These were factory mulled I believe.

I'm working with the manufacturer to get a replacement on the windows. Neighbor discovered his leaks during builder warranty period so has had an easier time. Anything you recommend I check? One thing: I looked at a similar double window on the lower floor of house I could reach with the ladder, and on top of the middle of the window (right where the windows are mulled), there are two screws with washers. Is this normal part of the mulling? Didn’t know if this is possible culprit of water penetration, assuming leaking window has same screws.
Thanks for any thoughts you may have.
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HomeSealed
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Re: Guidance on leaking double window

#2 Post by HomeSealed »

The vast majority of leaks enter at the top, even if the water manifests underneath. My first course of action would be to pop off the piece of siding directly over the window and ensure that the nail fin is properly integrated into the water management system (under housewrap, flashing tape intact, etc).

If that is eliminated, then its possible that there could be infiltration occurring through the window sill via a crack, incorrectly placed screw, or something of that nature. You could pour water in the sill (sounds like maybe you already did?) to see if it leaks.
The mulls are an unlikely source, you can rule them out with a quick bead of clear silicone over them from the exterior.

WindowsDirectCinci
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Re: Guidance on leaking double window

#3 Post by WindowsDirectCinci »

It's been a while since I have installed or had much to do with Alside windows but I believe they may run screws in a mull plate at the bottom of the window through the sill. At least they did 2008-2010. The location of the leak in the center bottom would suggest to me it has to do with the weep drainage system possibly having a crack in the frame or screws through the seal. I would start with pouring water in each window to rule that out.

fisherman
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Joined: Tue Feb 23, 2021 2:20 pm

Re: Guidance on leaking double window

#4 Post by fisherman »

Thanks for the replies and suggestions. Yes, I've tried a couple of times pouring a generous amount of water into the sills, which then makes its way down into the pocket sill via side cut outs, and water then comes out the exterior weep holes. That said, hard to say if I am pouring in enough water to replicate a rain storm. The sill itself is fixed in place unfortunately, so no way for me to lift it up and inspect how the water is traveling out through the sill cavity and out the weep hole. As you suggested, there could be a crack somewhere in the sill or penetration.

Every storm the water penetration tends to be a bit different. First time, water came down the middle of the window, as pictured. Another time, it appeared further down the wall. I think this mostly had to do with the water finding the path of least resistance. The double window on the first floor directly below this leaky window had water leaking in from the top once, but it's quite possible this water was simply the water that had penetrated the house from the window above on the second floor.

As far as the screws I posted in original post, I've since realized when I pull down the upper sash, I can see the screw coming down into the top of the window....so I need to check this screw and cavity next time it rains
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Windows on Washington
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Re: Guidance on leaking double window

#5 Post by Windows on Washington »

Better than 90% of the twin units we have ever seen leak are from the interface with the siding and at the mullion.

Start with the recommendations of HomeSealed above and work from the top down. Pouring any significant amount of water on the sill would be enough to verify drainage.

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Randy
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Re: Guidance on leaking double window

#6 Post by Randy »

One of the many problems with pocket sills is that if the corner weld cracks (even slightly), it will leak water into the wall, and it is very hard to find. You may be pouring water into the sill and seeing water run out of the weep holes, but hard to tell if the quantity of water exiting is the same as was put in. I would try covering the weepholes up with duct tape and then pouring a little water into the sill and see if it the level holds.

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TheWindowNerd
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Re: Guidance on leaking double window

#7 Post by TheWindowNerd »

Two observations:
The unit was foamed in place. You may want to scrape out the foam between the window and the sill plate to view any water leak.
A mechanical Z drip cap would prevent a top leak.

theWindowNerd

fisherman
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Joined: Tue Feb 23, 2021 2:20 pm

Re: Guidance on leaking double window

#8 Post by fisherman »

Hi all,

So an update to my leaky twin double hung window. Per my photos earlier in this post, I noted that these twin double hung windows have two screws (with washer) drilled into the exterior top of the window right above where the windows are mulled. I believed these were factory mulled, but not certain. When inside the house, by pulling down the top sash I can see these two screws penetrating down into the middle of the window cavity — one visible from each window. Well, during today’s rain, I pulled down the sash to check screws on both sides and they are wet and leaking water in. This water seems to drip/fall down into the center of the window cavity (not falling into the sill side or pocket system), so my thinking is this is the water that is flooding out into the house. I checked another non-leaking twin double hung window on same side of house right below the leaky window, same screws, and see no water on the screws.

Any thoughts on this or what these screws are? Is caulking, either from the inside or outside, an option to try before ripping apart the install or replacing the window?

Here’s a video if helpful… sorry for shaking cam… the shadow by screw is water, which I touch with the q-tip:

https://youtu.be/6m-CsNEoAWA
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WindowsDirectCinci
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Re: Guidance on leaking double window

#9 Post by WindowsDirectCinci »

Its factory made that way. A poor design yes. It looks like you can access it from the exterior, If it were me I would back the screw out and fill the whole with caulk then put the screw back in and cover with caulk.

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TheWindowNerd
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Re: Guidance on leaking double window

#10 Post by TheWindowNerd »

+1

fisherman
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Re: Guidance on leaking double window

#11 Post by fisherman »

WindowsDirectCinci wrote: Sun Mar 28, 2021 7:21 pm Its factory made that way. A poor design yes. It looks like you can access it from the exterior, If it were me I would back the screw out and fill the whole with caulk then put the screw back in and cover with caulk.

Thank you. Will give this a shot!

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HomeSealed
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Re: Guidance on leaking double window

#12 Post by HomeSealed »

Agreed. Pretty easy to do to either fix the issue or rule it out as the main culprit. Sounds like its at least contributing if not the entire source of the issue.

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toddinmn
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Re: Guidance on leaking double window

#13 Post by toddinmn »

It would be nice to get a drip cap on there.

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