Installation question

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RnRJefro
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Joined: Thu Apr 18, 2013 7:42 pm

Installation question

#1 Post by RnRJefro » Fri Sep 06, 2013 3:18 pm

Hello Everyone,
I am hoping someone can give me some insight on a vinyl window installation question.

I have installed or helped with the installation of quite a few windows over the years in friends and relatives homes. We/I always used or made up some sort of drip-edge for the top the window...if the window frame protruded from the house. Recently, I needed some second floor windows installed in my own house and since I am terribly scared of heights, I had to have someone else install them.

My house has aluminum siding. The company that installed the windows used vinyl J-channel around all 4 sides of the window opening, capped all 4 sides and caulked between the J-channel and the capping...and caulked between the capping and the window frame.

I am ok with 3 sides of the window but it seems strange to me to use J-channel on the top. It looks good but I worry about water getting behind the siding/capping. I would have used a small drip-edge and caulked the drip-edge to the siding so that water couldn't get behind it. I prefer water running off as opposed to leaving a "cup" for water to build-up in. If there is ever a blockage by something (dirt, bird droppings, dead bugs, blowing leaves, pine needles, sap, etc., etc.), rain could possibly build up high enough to backup under the siding. Being second floor windows, I would never know there was a blockage until something rotted away.

So...my question is....
Is J-channel acceptable to use on the top of the window?

I should also mention that no sealant was used between the J-channel and the aluminum siding. It think I might be ok with it if a bead of caulk was applied to the J-channel before being pressed onto the top.

Jeff

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HomeSealed
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Re: Installation question

#2 Post by HomeSealed » Fri Sep 06, 2013 4:12 pm

I would have just run the capping against the aluminum siding and caulked it, along with a drip cap on the top as you suggested. Their method could be ok,as long as that top piece of J was back-caulked, but it would not be my method of choice. Is it acceptable? That is a tough one. I'd say that you shouldn't have problems, as the j should expel the bulk of moisture, and aluminum doesn't allow a ton of moisture behind it anyway. I guess I'd prefer at least a drip cap between the window and top piece of J.

RnRJefro
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Re: Installation question

#3 Post by RnRJefro » Fri Sep 06, 2013 10:25 pm

Thanks for the input. That's what I thought also. As I mentioned, they didn't back-caulk the top J-channel. I would be fine with it if they did.

I'm not going feel 100% comfortable until I either add a drip edge/cap to the top or I seal the top piece of J-channel somehow.

Hopefully, I can find a very low profile drip cap so I can seal it to the top without ruining the flush, "balanced" look it has now. They did a siding cut-back so the capping is pretty much flush to the siding. It doesn't stick out like the capped brickmould look I have seen on many installs. Too big of a drip edge will look funny I think...like the bill of a baseball cap sticking out.

There is not any room to get behind the J-channel now but if I can't find a drip cap I like, I'm going to have to simply caulk the J-channel to the siding so no water can get into the channel.

TheWindowNerd
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Re: Installation question

#4 Post by TheWindowNerd » Sat Sep 07, 2013 3:27 am

Did they use a vinyl J or bend their own aluminum J?
Either way another possible way to add more protection would be to cap the top J.
Something like a 1/2" return from the window to edge of J, up 1/1/8" , ~ 1" return leg to siding with pitch to shed water, caulk where it meets siding.

theWindowNerd...

masterext
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Re: Installation question

#5 Post by masterext » Sat Sep 07, 2013 9:26 am

They should of back caulked the top piece of J and it would of been acceptable.

RnRJefro
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Re: Installation question

#6 Post by RnRJefro » Sat Sep 07, 2013 8:38 pm

Yes Anthony, that's what I am going to look for. Basically a piece of V shaped, white coated aluminum with one leg longer than the other. Sort of a J-channel but with the legs spread a bit to make more of a V shape. I'll tuck the longer leg down into the vinyl J-channel they used and then I'll caulk it to the siding.

If I can find one with only a 1/2" or so short leg, it shouldn't be too obtrusive.

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