Home>Discussions>EXTERIORS>Rotting exterior window trim
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Samuel Seward
Rotting exterior window trim


We built our house 8 years ago. It's a basic Cape with 3 dormers. All of the exterior window trim on the 3 dormers is rotting. The rain appears to bounce off the roof and has penetrated the siding, causing decay, in record time.

Any suggestions about the following:
1) what material should I use to replace the trim. MDF? Plastic? It will need to hold paint and appear to be wood or the look of our cedar house will be for naught.

2) what kind of preventive measures do you suggest behind and around the trim to keep water from penetrating underneath?

Any advice will be appreciated!


Re: Rotting exterior window trim

I would suggest that you get hold of a good carpenter. Eight year old window trim should not be massively failing. You need a carpenter to determine what was done wrong before you simply duplicate what was done before. He should check for proper weather screen, flashing and caulking.

Re: Rotting exterior window trim

Ideally, the siding should be painted on all sides, even the reverse.good luck!

Re: Rotting exterior window trim

I have seen and repaired so much of this kind of water damage, and have concluded that it's caused by caulking placed where one should not caulk. Water needs a place to escape at the bottom; never caulk horizontal bottom joints in the casing.
We have been replacing with spanish cedar and mahogany, fully backprimed and end-sealed.

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