I posted this over in windows, and just realized this might be the better place to get an answer:

I have a 14 year old house, that is almost entirely stucco. The windows are wood interiors with exterior vinyl. The walls are 2x6, so there is a decent sized vinyl sill that is sloped away from the building. Windows on the sides and back are wrapped in 6" wide cedar trim. Windows in front have stucco right up to it, with shutters on top.

I built the house, but wish I would have known then what I know now. Looking at pictures from construction, I can tell the following:

• Windows were placed directly into rough openings (no wrap yet) -- with decent size nailing flanges
• A head flashing was put in directly above the window (and only covers the width of the window)
• For the back and sides, the cedar trim was installed next (no flashing). Another head flashing was put above the top trim, covering the width of it
• Jumbo Tex paper was installed around the whole house (I believe 2 sheets of it), then wire (with weep screed). These butt up directly to the windows in front, and to the trim on the others.
• Stucco was installed

Thankfully I have had no leaks inside that I can see, except for a fixed window in a two story great room where the exterior caulking between the vinyl sill and jamb mitre failed and let water drip in (became visible coming out of the top of the window below it).

What is concerning me now is that every year I am starting to find one or two pieces of the cedar trim rotting out -- always in the lower piece right below the corner of the window. I have had the entire house painted and caulked (stucco to trim, and trim to window). Yet I found one more this year.

That tells me that maybe water is still getting back there, and the lack of flashing is opening me up to more serious problems. Before painting this year, I did not notice any significant "stucco tears" at the corners, but that doesn't mean there isn't damage behind the trim. Or, it could just be the water working in at the joints on the front.

Given all that -- and I know they are not flashed, I want to find a way to flash my windows, ideally without having to replace them, or having to pull them completely (I understand that might not be possible, and end up being the final resolution).

I was thinking of doing the following, but not sure if this will actually be of any benefit at all:

1. Pull all the trim off a window
2. Remove the head flashing just above the window, and install a new one that covers the width of the window and trim combined
3. Install flashing tape over bottom fin first, then sides, then top
4. Reinstall cedar trim.

This does not solve the problem of lack of a sill pan, or having the flashing integrated into the tar paper for the stucco. But if I am already replacing a piece of trim, seems like this would be worth doing at the same time.

Thoughts?