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Sow Bugs under window sill

  • Last Updated:
  • Jun 14th, 2020 1:32 am
[OP]
Member
Jul 26, 2008
438 posts
477 upvotes
Montreal

Sow Bugs under window sill

My son started noticing small sow bugs on the wall of his room.

Every hour we will see one bug sometimes they are on the floor so the exact point of entry is still unknown. I removed the trimming from around the window, and the sow bugs might be coming out from under the sill. The windows appear to be aluminum with a white foam on the inside.

Sow bugs indicate moisture, rooting wood I presume ?

I ran a humidity meter for walls and I get reading of 15% humidity which is the same value I get everywhere in our home.

The small bits of mineral wool I pulled out from the gap between the window and wall were all very dry.

I think the best option would be to remove the entire window frame to see where water is leaking , remove sow bugs seal, reinstall window frame ? ( does this sound like the best approach ? )

or the jobber approach would be carve out 1 inch of gyprock from 4 corner of the window, spray with insecticide, air out a few days and seal gap with foam, Easy but does not address the root issue)

Area in red wear I think sow bugs are coming out of.
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Window is tight on the gyprock, bottom left corner where I remove mineral wool from a hole, everything is dry ?
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Outside view, Second story window
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Any idea on how the windows comes out, cut the mount screws and it goes out from the outside, requiring scaffolding on the outside to catch rest the window ?
5 replies
Member
Feb 26, 2019
427 posts
370 upvotes
Ottawa
Sow bugs above ground definitely suggests moisture to me.

You could start by cutting back some drywall to take a look and see if you can figure anything out.

You’ll likely need to get a look behind that siding outside too. You can’t necessarily assume that the window itself is leaking, it could just as easily be the flashing or installation details around the window. No way to tell that without getting a look at it.

It’s probably not the head flashing that is leaking, because the top of the window is well protected by the roof overhang. I would start by removing some siding directly below the sill.

How old is the house/window? Is it the original window?
[OP]
Member
Jul 26, 2008
438 posts
477 upvotes
Montreal
dottawat wrote: Sow bugs above ground definitely suggests moisture to me.

You could start by cutting back some drywall to take a look and see if you can figure anything out. ( that's what I will do next, just needed to let that sit with my wife for few days. )

You’ll likely need to get a look behind that siding outside too. You can’t necessarily assume that the window itself is leaking, it could just as easily be the flashing or installation details around the window. No way to tell that without getting a look at it.

It’s probably not the head flashing that is leaking, because the top of the window is well protected by the roof overhang. I would start by removing some siding directly below the sill.

How old is the house/window? Is it the original window? (Built in 1986, we moved in 2015. I think windows were replaced by previous owners.)
In 2015 we had the patio door replaced and I took a picture of after the old door was removed :

This show a slice of wall, At the time I did not know anything about flashing, which was completely missing so I suspect it's a similar story for the upstairs window.
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I am not looking forward to getting the sliding off, its aluminum. I have never touched that stuff. I will remove the bottom gyprock investigate and wait for warmer weather to remove the window and sliding.
Member
Feb 26, 2019
427 posts
370 upvotes
Ottawa
Makes sense to me. See if you can learn anything from the inside. Once the weather improves, you can take a look outside.

Before you start pulling off siding, Just be aware, you could be into a decent sized repair project. So make sure you have some cash set aside to see it through (or time if you are handy). If it is water entry at the window, there could be some significant remidiation needed. Depending on the age of your house, the wall sheathing could be OSB. If it is, it can lose integrity quickly from water exposure (especially the older stuff). So you may need to replace some of it, in addition to reinstalling windows. Not to mention repairing or replacing siding around any infected area.
[OP]
Member
Jul 26, 2008
438 posts
477 upvotes
Montreal
Finally had time to bring down the window with ladder and rope and pulley

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There was no rot in the wood frame under and around the window, same deal as my patio doors, It was apparent that these windows were not original, I found old screws hammered in . and and one of the 2x4 was carved with an axe to fix the current windows which was larger than the original

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This was the top of window, where these was clear air infiltration. so during the cold months, air would get in and condense on the inside of the window attracting the sow bugs (my guess)

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I tapped up the tyvek, back to to window frame and covered the entire inside wood from bottom and side with a flexible flashing product, with a slant towards the outside. The top of window has a proper flashing starting behind the metal siding.

Window frame when back up, I taped all around so air would not get in the foam part.

After installing from the inside I put a foam backer all around, pushing in from the inside, and I then filled the void with window closed cell foam all around. Not sure what a pro would have done. But I had no appetite for removing the siding on the house, and tape from the outside which would have been the ideal repair.

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Is so depressing that the window installers who did this job did not properly air seal the window, the gaps allround were just filled with mineral wool.
Deal Fanatic
Jan 25, 2007
9934 posts
5227 upvotes
Paris
Why the backer rod?

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