Replacement Window in Brick Opening

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John.allenby
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Joined: Mon Mar 15, 2021 2:50 pm

Replacement Window in Brick Opening

#1 Post by John.allenby »

I am planning a DIY window replacement. The existing window is a double hung sash window in a brick opening. The replacement window is a fibreglass casement window. This new window has an optional brick mold that clips on the window frame, and has a nailing fin/flange. With the fin/flange removed the side of the brick mold is flush with the side of the window frame.

I've installed windows before, but not into a brick opening, and I'm wondering how to fit or trim into the brick opening.

This replacement is part of Reno work and all internal/external trim, sash pulley boxes... will be removed. I was thinking of building a new window buck slightly larger than the brick opening and using the brick mold nailing fin to attach to the buck. This would leave a gap between the brickmold side and the actual brick. Do you then add another filler piece for this gap and caulk to brick on one side, and to brick mold on other side. Or is there a better method ?

John,

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Windows on Washington
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Re: Replacement Window in Brick Opening

#2 Post by Windows on Washington »

Lets see what you are looking at and why bother with the re-trim? If you are building a buck for the opening, which you will need to in order to make sure that the window is slightly smaller than the brick opening, why yank out all of that to re-do it?

John.allenby
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Joined: Mon Mar 15, 2021 2:50 pm

Re: Replacement Window in Brick Opening

#3 Post by John.allenby »

Here is a pic of the existing window. House is 90 years old and windows may be as old. Also a pic of the brick mold for the new window
Fiberglass-Windows-Trimeline-Brickmold-casing.png
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20210310_085759.jpg (140.34 KiB) Viewed 751 times
The existing external trim is very old wood and the caulking is cracking. I don't mind spending the time to remove it.

Here is a pick on the internal trim that I've started to remove.



John,
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Windows on Washington
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Re: Replacement Window in Brick Opening

#4 Post by Windows on Washington »

If the window hasn't leaked before, I am always hesitant about full tear outs behind brick.

Here is the reality of your opening, as I see it:

1. You are going to get a larger net glass opening with any insert
2. You are disturbing something that has otherwise worked by keeping water out of the house
3. There is NO reality in which you find wood that is as good as what is on the interior trim now
4. You can effectively insulate the weight boxes as part of an insert installation
5. You can clad the exterior trim and replace any small sections of rotted wood, surgically prior to capping

John.allenby
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Joined: Mon Mar 15, 2021 2:50 pm

Re: Replacement Window in Brick Opening

#5 Post by John.allenby »

Ok, I can leave the exterior trim (brown) in place, but still unclear about the joint between the new window frame with or without the brick mold. Do you cut and fit new exterior trim over the old exterior trim and fit to position of the insert window. Or leave existing external trim and add new trim stepped back and fit in place. I've got room to work with as I below it is double brick construction, with current a storm window in front of the fixed windows.

Thanks,

John,

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TheWindowNerd
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Re: Replacement Window in Brick Opening

#6 Post by TheWindowNerd »

It depends on your preference and the RO, MO, and frame size desired.
I would tend to set the new unit out into the MO and fasten through the jamb. You have to consider the exterior trim details and water management system that you choose to use.
I would pre install a mechanical alum head flashing.

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