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Window corner crack

Hi all,

Is this stucco crack in the window corner considered normal? Facts:

House is 1969. The window was new installation + stucco that was just installed this April. The window was to replace a retrofit window that has had some leaks on this side of the window for a long time.

Should I be concerned? Will this get any worst?


Re: Window corner crack

I don't think your window meets minimun code requirements.
I see NO sill flashing.
NO caulking joint at jambs.
Can't see heah but will bet NO head flashing is installed.
ALL the above are required by the window manufacture.
As for the crack it is normal for stucco to crack at corners it is a stress releif point.
Could be from moisture still present at the corner.
Note the dark area about 3 inchec high and about 1 inch wide at the lower corner this would indicate a moisture problem still exist.

Re: Window corner crack

Very appreciated for your feed back.

I watched them as they installed the window and it seems to follow what is called out in my city's building inspection division:


1) Installed flashing paper on bottom, then sides of opening.
2) Caulked window flange top and sides, no caulk on bottom.
3) Nail flange to opening, and cover top flange with flashing, and then finally cover the flashing with the house wrap.
4) Lath, then put on stucco.

When we opened up the stucco, we tested a few points where the leak could have possible traveled to, and we found that the wood at the foundation felt a bit moist. The original plan was to put in window and replace any damaged wood, but being in the middle of the rain season, and I didn't like how the project kept getting delayed (I wanted a full time contractor, not someone who can only work 2hrs / day as he later told me). Anyways, I told them to just put in the window and stucco it up. I will have to revisit this wall and fix the wood at a later date. The contractor told me not to worry about the wood, saying it will dry up over time. Is this true?

In your opinion, what is the best and most efficient way to do replace the wood? Do I have to take out the window again, or can we do the repair around the window?

Re: Window corner crack

This is how we install windows around here. Stucco gets wet all the time, and that's normal - the water can't penetrate the house wrap (if done correctly).

1. The crack in the stucco. That's normal and happens all the time. Solution: Elastomeric caulk, then elasomeric exterior paint.

2. Wet wood. Wet wood should be allowed to get dry before covering it. If you don't, you'll have dry rot. To replace the wet wood now, remove the window, since the flashing is attached to the wet lumber. Sorry.

Re: Window corner crack

In your steps of installation you stated house wrap over the flashing ?
If that was the case your contractor directed the water that may / can get in to the window behind the house wrap ALL WATER should be directed to the outer side of the wrap directly behind the stucco.
You need to check the window manufactures installation detail as to what is required for caulking between window frame and stucco.
ASTM 926C Stucco & 1063 Lath and Furring , would require casing beads at termination points of the stucco system
Caulking & backer rod is required between the casing bead & window frame.
If no backer rod is used a bond breaker is required behind the caulking.
Caulking should adhere only to the bead & window.

Re: Window corner crack

"In your steps of installation you stated house wrap over the flashing ?"

The way I do it:

Bottom and side flashing over the 60 minute tar paper. Top flashing, under the tar paper.

Same idea if you use house wrap.

Re: Window corner crack

Yes, what I meant to say in the process was that the sides and bottom flashings covers the house wrap. The top flashing covers over the side flashings, and top house wrap covers over the the top flashing.

When I was out walking during lunch at work, I saw a house that has been having an exterior extension/remodeling for the past couple of months. I basically watched it went from frame to siding. Even with their new stucco siding, I saw that the corners of the windows showing the same crack as seen in mine.

Re: Window corner crack

A hair line crack is not a problem. A 1/2" crack is a problem.

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