We have had ongoing issues with two windows in our home, a big office window and then another in our laundry room. Both of these operable/large windows face west (front of house) and both are located under dormers (single story home). The issue is that when we get a certain type of rainstorm, specifically harder blowing rain, we get water dripping down inside from above the windows and eventually it ends up dripping down the glass, sash, and apron/trim at bottom, etc.

We have already had the builder come out twice in the past and they redid some of the flashing around these dormers. Eventually the issue resurfaced. Most recently we had a roofer friend in the neighborhood re-caulk some of the nails around the flashing that he said would need to be done routinely every couple of years.

At this point we plan on moving forward with our roofer friend to redo the entire areas around the dormers (new flashing/shingles, etc.). He has been kind enough to ask questions before starting and is trying to decide if it is a window or roof issue. The small windows on these dormers have no function and go into the attic. During rainstorms I have not seen any moisture at these windows on the inside, however they are hard to get to and we have the entire attic spray foamed.

Does anyone have any experience with this? Any suggestions on how to narrow down the issue or does this in fact seem like a roof/flashing problem that should be redone?

TIA!

I have had to chase leaks I didn't think I would ever find. In this case, your roofer should perform a leak test. It's very complicated and technical.....

Take water. Dump it in various places on the roof or windows. Watch for the leak.

Your roofer should be familiar with this and he can help pinpoint the area. Intermittent leaks are the absolute worst and you can dump a lot of money reroofing, reflashing, etc if you don't have a little idea. If you have a long enough water hose, this would be ideal for a test like this. He'll need to work from the lowest potential area, to the highest potential area and work in small areas until he can pinpoint the problem area.

As a personal anecdote, I had a leak in one of my houses at my chimney. I reflashed, caulked, redid, for a year before leak testing and finding a leak in my masonry where the water would come in. A 3" bead of Geocel, and a a sealant over the chimney and that was fixed. So, maybe your leak is simpler than you expect.

Thanks for that advice! I have plenty of hose that would allow for a test like that. Should be very easy to simulate wind blown rain. Makes me feel at least a little better for not being able to solve it yet.

At the end of the day, I have the same issue in two spots, both below dormers so it seems that is obviously the common denominator.

It may or may not be a easy fix but like jason said you can find the leak with a waterhose or thats the way I have always helped people

Anybody that comes out and says they can fix without trying to actually duplicate the problem first in my opinion should not be used (unless it is a obvious leak and no searching is required )

But if it leaks everytime with a certain wind ahould be able to find pretty quick

I agree, it should be something I can produce with this test. I will be chatting with my neighbor (roofer) about it and see if he's done tests like this before.

Before Velux self-curbing skylights, poor framers would build curbs then flash them that leaked, while Master Framers had no problems. Back then 70s-80s some top homebuilders refused to install skylights due to leak callbacks. Clerestories were OK, even though better flashing of them AND dormers we have today.

Include chimneys and all these problems can share the flasking problem, often solved with thru-masonry or tall-behind-siding metal flashing with plenty of back-sealant as a genesis.

That's my penny bet ... if I can find one.

The windows today have nailing fins and great care is sealing like never before.
That said, attended a church with East facing windows that leaked during East coming storms ... but between the custom muntins/mullions in that huge "sail" of glass.