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window trim dilemma

dot1 | Posted in General Questions on

My house was built in the early 80’s.  It is mostly stucco.  The lower level northside is brick.  And the trim is cedar.  The trim is kind of fat — extends out from the stucco approx. an inch. 

Recently had new windows installed on one side (there are only windows on the north and the south sides).  I’m debating whether or not to go with the same fat trim (2 inch — though I think that lumber measurements differ from regular measurements and it might be a little less than 2 inch).  Or go with 1 inch.  The problem is that the 1 inch is almost if not exactly flush with the stucco and slightly less than the windows.  Does this matter?  The windows would protrude past the trim a tiny bit.  Hopefully the trim would protrude past the stucco a tiny bit — though it might possibly be flush. 

The cost of cedar has skyrocketed, and I don’t like killing trees.  Would like to use the less thick cedar, but not sure that’s ok.  The other thing I thought of would be to have little spacers to bring out the 1 inch cedar more and nail into that.  An air pocket would then be behind part of the trim between it and the peel/press flashing. 

I looked into other options.  Initially, I thought I’d just have the area filled in with stucco until I found out that the wall would have to be cut back into to lay the wire.  Then I looked into the foam bumpouts, but I hate the idea of all that styrofoam, and matching the finish would be complicated.  Also looked at Hardie trim, but got loads of negative feedback from carpenters on that stuff and the availability in my area is very iffy.  So I came full circle back to wood and am now just hoping to minimize the amount of wood used.

Would appreciate hearing opinions on what the best thing to do is.  Thanks.

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  1. onslow | | #1


    The description you provide is unclear to me. Are these replacement windows in existing locations? Are they window inserts that set into old window frames? The peel and press flashing mentioned infers the siding material present has been cut back beyond a new window opening to allow for the window flange to be flashed. If not, then I don't see how the flashing could be installed properly. If the location is a new penetration of the stucco system, then detailing is even more important.

    I am guessing that the existing/former window trim is wide 2x stock framing the window. Shimming nominal 1x stock to stand proud of the stucco(?) might save a bit of lumber, but at the cost of fussy labor. The gap behind thinner material on shims might invite water to find paths not otherwise available. Caulking the trim to siding and windows will buy time against the elements, but proper flashing of the window and proper WRB details are the long term answer.

    If you post some photos and a cross section diagram (as best you can) more useful help may be provided.

  2. jamesboris | | #2

    Claim I don't have time to defend but nonetheless will share and slink into the shadows as people defend Next Best Thing materials: A quality piece of wood, well-detailed and well-maintained, will not fail, and will have a lifetime lower environmental impact than other alternatives in this case... among other reasons, because wood is more inspiring than PVC and fiber cement, and uninspiring houses fall to ruin when they don't inspire people to take care of them... even Lstiburek says that!

  3. Expert Member
    Michael Maines | | #3

    Dot, when joining two different materials it's a good idea to leave a reveal rather than making them flush with each other because they will expand and contract at different rates. You may not have to go to the full 2" depth but I would aim for at least 1/2" proud of the face of the stucco.

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