Cold spot behind drywall


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Old 10-19-22, 07:52 AM
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Cold spot behind drywall

We live in a row townhouse built in 2001 in Toronto, Canada. Since we moved in about 4 years ago this one room has always had between 1-2 degree celcius temperature difference than all the other rooms in the house.
I got my hands on a thermal camera and it shows a big square air leak behind the drywall above the window. There's nothing to see on the interior or exterior wall and no signs of damage on the wall itself. Any idea what the issue is and how I can remedy it?
I can also see air leak all around the window frame, these were new vinyl windows installed in 2017 and all the rooms have a similar air leak pattern around the frame which makes me think the installers didn't install it properly or didn't insulate properly. Is there something I can do about this? Thanks.

 

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10-20-22, 05:30 AM
Pilot Dane
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I actually find it easier to repair if you cut a larger hole since you somehow have to mount the sheetrock. Find your stud locations. Cut down the center of the stud. That way the existing and repair sheetrock are each supported by half the stud. If you cut a smaller hole then you have to screw pieces of scrap wood to the edges of the old sheetrock so you have something to screw the new to. Keeping the patch small doesn't really matter since your messing the wall up anyhow so your going to have to repaint.
 
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Old 10-19-22, 08:47 AM
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I love thermal cameras! A very handy tool.

Look at other windows around the home. Do you also see a cold spot above them and doors as well? If so then it is probably the structural header. If that's the case there isn't too much you can easily do since the structure is almost solid wood leaving no room for insulation.

If it is only that one window then insulation may not have been installed during construction. You can remove the drywall from that area and install insulation. Repairing the sheetrock doesn't bother me nearly as much as the repair almost requires you to at least repaint that entire wall and possibly the room to get it to match.

As for the cold around the window that is rather common. If it is the window frame itself there isn't much you can easily do. But, if it's the gap between the window frame and the house's framing that can be fixed. You would need to remove the trim molding then fill the gap between the window frame and house framing with insulation. Then reinstall the trim.

While you have the camera also look at any vaulted ceilings or dormers as they often have insulation problems. Look at the electrical outlets and switches on exterior walls as they too often have gaps in the insulation and are easily fixed. Then look where walls meet floors. The rim joist around the perimeter is another problem area.
 
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Old 10-19-22, 10:13 AM
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Thanks for the very helpful reply. This is the only wall with that type of a rectangular cold spot so I'll probably take a look behind it when I can.
Are you aware of any expanding insulation products where I could just remove a very small section of the drywall so there is less to patch?
 
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Old 10-19-22, 10:25 AM
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IMO you are better off removing what drywall you need to in order to get the insulation right. An expanding foam may or may not reach the entire area and could put undo pressure on the drywall when it expands. Drywall repairs aren't overly complicated and we can walk you thru it if need be.
 
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Old 10-19-22, 11:06 AM
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I agree with marksr. I've had some crazy bad & weird experiences with expanding foam. One is the expansion pressure which can bulge the wall out. Also, spray cans don't work well when filling large cavities. The outer portion hardens while the core remains liquid so you don't get good expansion or gap filling. The best would be a two part foam but kits are more expensive and you can still have the bulging problem, ESPECIALLY if you get the foam amount incorrect. It can generate a lot of pressure when it expands.

If you are concerned about privacy I would edit your photo to remove or blur the Lat & Lon coordinates. Your townhouse looks nice. The brick exterior means attacking the problem from the inside is definetely the easier way to go.
 
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Old 10-19-22, 11:31 AM
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I'm OK to patch the drywall if needed.
Any suggestions on how to go about adding in the insulation and what products I'll need? I'm unfamiliar with this area of DIY.
Most of what I can find online points me to spray foam insulation
 
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Old 10-19-22, 11:47 AM
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If the space is clear (no pipes, ducts, minimal wiring, etc.) you could use solid foam board for a very high R value. Cut to size, overlap any joints between layers and seal edges with tape or foam.
 
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Old 10-19-22, 12:49 PM
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Just cut a 12" square hole and get a small roll of insulation, fiberglass is problaby the easiest and just cut and stuff pieces through the opening to fill the void!
 
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Old 10-20-22, 05:30 AM
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I actually find it easier to repair if you cut a larger hole since you somehow have to mount the sheetrock. Find your stud locations. Cut down the center of the stud. That way the existing and repair sheetrock are each supported by half the stud. If you cut a smaller hole then you have to screw pieces of scrap wood to the edges of the old sheetrock so you have something to screw the new to. Keeping the patch small doesn't really matter since your messing the wall up anyhow so your going to have to repaint.
 
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