Doors and Windows - Leaking window after ice fog

Dear DIY,

We have noticed some leaking on the top of one of our window frame from one of our living room windows. It happened in mid-December after we experienced 3 consecutive days of ice fog and a thaw on the third day. We have never noticed a leak in this window despite getting record rain falls last summer. Our house is a two story house where the living room is on the main level and there is no window directly above the affected window. There is vinyl siding (make: mitten) and metalic drip edge above all the doors and windows.

The leaking seems to be coming from between the wall frame and the window frame (not where the glass attaches to the window frame). There was substantial buildup of frost on the vinyl siding of the house after the fogs and this window is on the south facing wall, which gets quite a bit of direct sunlight during the winter months here in northern Alberta, Canada.

At the time, I climbed a latter and checked the siding above the window and noticed that the J-Channel was full of water (source was likely frost that had thawed out from the vinyl siding above the window. In order to prevent further dripping, I cleaned out the water in the J-channel and dried as much of the siding above the window as I could with a couple of towels tied to my "painting pole". It eventually stopped leaking after I did this, but I am not sure whether these measures resulted in having the leaking stopped.

We have since noticed that the vinyl window frame has warped a little where the water was leaking, but the drywall is so far so good.

We have had no other window leaking incidents on this house, and there is only one more window along this south-facing wall.

Should there be serious concerns here?
If so, how can I find the root cause of the problem?

Thanks,
Derek

Ice can be a nasty thing, the damage can be out of sight. It could be roof damage, it may have pushed out the siding or underlayment wrap. The only thing I can suggest at this point is a careful inspection of the area above the window, or siding and roof overhang.

Do you have house wrap or building paper on your home under the vinyl siding?

Is the window properly installed with appropriate lapped and taped flashing techniques to shed water down the outside surface of the wrap/building paper?

Your vinyl siding is only meant to shed normal rain/snow. It is NOT a weatherproof layer. You may have had a buildup of ice under the siding that somehow got under the wrap.

Improper window installation can permit small openings that permit concentrated heat and air flow that will create openings that can allow water penetration.

I would look at the window installation/house wrap area for water entry points.

Dick

Thanks Dick & Just Bill,

I am assuming there is house wrap under the siding, but I cannot be sure. How can I inspect this further?

Could this problem really be caused by the roof or eavesthrough because the window is on the main floor of a two storey house? However, on the day in question the eavesthrough was filled with ice and snow on the roof was melting that caused the eavesthrough to overflow.

Derek

Where the water is getting behind the siding is almost immaterial. It could have been frost on the back of the siding, it could have been ice in your j-channel, it could have been an ice dam in your gutter causing water to flow down the house where it doesn't normally flow.

What the guys were describing is that it is possible that your window (if it has a nailing flange, or if it has a drip cap) is not flashed properly on top. That's what you'd need to investigate. If you just want to peek behind the siding, look for a seam (where one horizontal piece overlaps another horizontal piece, on the same row). Pull the seam apart in the middle so that it gaps open- you should be able to see Tyvek or something similar behind the siding.

To further investigate, you can unzip the piece of vinyl siding that goes over the top of your window with a special (inexpensive) tool- a vinyl siding unlock tool. (actually, you can unzip it with your hand, but you almost always need the tool to hook the siding back up again). Once you have the siding unlocked, you will be able to inspect the situation.

If you find that the nailing fin or dripcap is on top of the building paper, you'd simply need to cut a flap in the building paper, fold it up, and then tape the nailing fin or drip cap to the sheathing (using Grace Vycor, Tyvek Straightflash, or similar) and then fold that flap back down and tape it's edges.

Thanks XSleeper, this is the info I needed!

Derek