structural support for picture window.

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bigslink
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structural support for picture window.

#1 Post by bigslink » Thu Jun 20, 2019 9:52 am

I'm looking to replace 3 windows in my living room. The RO is 128" x 50". The dh\fixed\dh dimensions are 24.5 x 49.75 \ 77 x 50 \ 24.5 x 49.75. I want to replace these windows keeping the same dimensions and changing the dh to casements.

I am looking at Atrium 8700 (fixed & casement) , Okna 500 (fixed) 700 (casement) windows want mull kit to attach the new windows. I was told that my fixed window is very large and that it would need more structural support than is would get if installed using the mulled method. Is this true? Am I unable to get more glass area, because of the size of the fixed window?

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Windows on Washington
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Re: structural support for picture window.

#2 Post by Windows on Washington » Thu Jun 20, 2019 12:14 pm

Pictures will help here and I can provide some more insight.

bigslink
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Re: structural support for picture window.

#3 Post by bigslink » Thu Jun 20, 2019 2:32 pm

Here's a photo for your review.
window.jpg
(144.86 KiB) Not downloaded yet

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HomeSealed
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Re: structural support for picture window.

#4 Post by HomeSealed » Thu Jun 20, 2019 3:13 pm

A couple of confusing things here:

1) If your flanking units are Okna 700 casements, the center PW should be in the 700 frame as well. No reason to use a 500 frame, it would look weird with the different exterior profile.

2) Without seeing this from the interior, it doesn't look as though there would be studs at all, let alone load bearing coming down in the mullions of the existing unit. The window is also under the maximums for width, height, and UI, so no issue from a product perspective... There should be a continuous header existing above this opening, and THAT is what bears the weight of the load from above. The existing mulls are simply the buck frames back to back and offer little support. The only thing that may have some legitimacy IMO, would be for deflection on a large unit. Perhaps they've had clients complain about that in the past, as large mulled units can get a little "flexy". There is also the fact that they would need to be field mulled based on the size, and they might not like to do that...

In short, no, there is nothing preventing a mulled unit to be installed there (short of discovering studs between the existing units which again looks unlikely)... They may have a valid preference for not doing so though...

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Re: structural support for picture window.

#5 Post by bigslink » Thu Jun 20, 2019 11:59 pm

The 500 pw was part of the quote, I can ask for a revision with a 700 pw. I've attached an interior pic for your review. So far, I'm glad to hear that the frames can be mulled without additional support.
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HomeSealed
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Re: structural support for picture window.

#6 Post by HomeSealed » Fri Jun 21, 2019 10:27 am

The 500 vs 700 thing may just be a misinformed sales guy.

On the mulls, you could pry off one of the mull caps to verify that there is no stud in there, but again, it doesn't look like it. Typically the mull would be a bit wider if that were the case.

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Re: structural support for picture window.

#7 Post by TheWindowNerd » Thu Aug 22, 2019 4:49 pm

Okna may not want to ship it mulled because of the length.
It may be better to order the units separate and put a 2x4 or 6 vertical mull in.
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Windows on Washington
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Re: structural support for picture window.

#8 Post by Windows on Washington » Fri Aug 23, 2019 10:12 am

Are they doing full tear outs here? No reason that they should in my opinion.

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Re: structural support for picture window.

#9 Post by masterext » Fri Aug 23, 2019 3:37 pm

We have done fixed windows that wide with no issues. The total width of that unit exceeds the width in which Okna will ship mulled. We field mull all the time. A field mull is no different than a factory mull.
That said, your total width is 128”.. why not do a conventional 1/4- 1/2- 1/4 ( 32-64-32 ) configuration in which case the fixed middle will be a little smaller? It would still be plenty wide for a nice view. That makes much more sense to me.

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Re: structural support for picture window.

#10 Post by TheWindowNerd » Sat Aug 24, 2019 2:00 pm

I agree with the 1/4 1/2 1/4
There is a small amount of difference with a factory mull.
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Ricknez
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Re: structural support for picture window.

#11 Post by Ricknez » Mon Sep 16, 2019 3:44 pm

mulling in the field can be a bit of a pain but sometimes we have no choice when its a large unit.

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Re: structural support for picture window.

#12 Post by TheWindowNerd » Tue Sep 17, 2019 6:26 pm

Also adding structural support mulls ( 2 x4 or 2 x 6) makes this install easier. I would take the 3" off the PW.
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jhoney
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Re: structural support for picture window.

#13 Post by jhoney » Fri Sep 20, 2019 9:19 am

The existing mulls are simply the buck frames back to back and offer little support. The only thing that may have some legitimacy IMO, would be for deflection on a large unit. Perhaps they've had clients complain about that in the past, as large mulled units can get a little "flexy". There is also the fact that they would need to be field mulled based on the size, and they might not like to do that...

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Re: structural support for picture window.

#14 Post by HomeSealed » Fri Sep 20, 2019 11:29 am

J honey, I'm flattered that you agree with my post so strongly that you've copy and pasted my comments verbatim, however using the (") button in the upper right corner to quote another contributor is a good and courteous practice. :)

toddinmn
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Re: structural support for picture window.

#15 Post by toddinmn » Fri Sep 20, 2019 10:02 pm

I’d have to agree with Jhoney, those comments were spot on.

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