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Exterior window trim; proper drip cap

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Aug 26, 2013, 11:43 PM
Exterior window trim; proper drip cap
I need to replace the trim on a couple of windows. I'd like the new cap to look similar to the old stuff (doesn't need to be exact).
In the attached image we see; the old trim, Azek Drip Cap, and Aluminum drip cap
Would I use the Aluminum cap under the Azek drip cap?
How do I fasten the cap to the window (trim)?
It seems that I need to minimize the use of nails and/or screws.
Is the drip cap installed with tight contact (possibly glued) against the top window trim?

This message has been edited. Last edited by: SturdyNail,

Existing cap w/possible replacements

Aug 28, 2013, 06:09 PM
The Azak drip edge is just for looks, it's the aluminum flashing piece that does all the work. When installed correctly, the aluminum piece goes up behind the siding, then out over the top of the window trim. This guarantees that any water cannot get up behind the siding.

You could install just the aluminum, but it doesn't look nearly as good - especially since you would like to match the existing look.

Aug 28, 2013, 10:39 PM
Thanks Jaybee. That makes sense.
How should I fasten the Azek? It seems I should minimize penetrations of the aluminum flashing.
Aug 28, 2013, 10:59 PM
Caulk it in place. Do not. Do not. Do not put any holes in the aluminum flashing!!!! The only place to nail through the flashing would be through the siding near the top edge of the flashing just to hold the flashing in place. However, most times even that is not needed as the flashing is pinned behind the siding and then caulked.