Just landed a project replacing weather damaged trim(preprimed spruce) on a building.
I want to get the window trim detail right. Existing trim on top of the windows is layed on top of the siding, t-111, no z-bar. As the wood moves, the caulk joint breaks and everything goes south.
Could you use z-bar in this case, over the top of the top trim piece, and how would you get it under the siding?
Thanks
Replies
There is simply NO good way to flash the head of window/doors with T-111 siding.
Moving the "Z" to above the trim just relocates the problem.
Flanged windows have what amount's to a flashing already built into them.
(Although windows that have a flange that have a"U" or "C" cross section are absolutely the worst choice in windows, The outside face to side and top corner should be just that , a sharp 90 deg corner.)
Really no matter how many ways you analyze it the answer comes back to a good caulk job done with the best caulk you can afford.
There just is no other solution.
Edited 9/8/2008 8:43 pm by dovetail97128
thanks for your reply. Yeah, this situation has always irked me to no end. With lap siding you can utilize z-bar, but not with t-111 like siding.It is usually not an issue when the window/door is protected by the elements, but as soon as you have massive exposure the wood moves and the caulk blows out and it all falls apart.I was thinking of using Azek pvc trim in those high exposure situations, but it does not come in 2x thickness.
re: the pvc .... still wouldn't matter ... the T1-11 will move ... got the same problem. How about removing the flange and roll the z flash up behind the T1-11? Still have the side, but getting warmer at the top ... then trim, etc. Just thinkin' out loud ... maybe just flapping my gums.
Cut a kerf in the t-111, right along the top of the trim.
Go slightly longer than the top of the trim.
Now, cut down from that kerf, to the top corners of the window. Straight up from the corner, NOT out at an angle to meet the outsides of the kerf.
Now remove the piece of t-111 that you have just cut out.
Install the z flashing under the t-111 at the top of the cutout, in that kerf. You'll have to work the flashing under the t-111, then sideways, into the legs of that kerf.
Cut two pieces and overlap them in the middle, if you must. But caulk that overlap liberally, (The caulk is like PB&J, in a sammich. And the flashing is like the bread.), and overlap at least 6 inches.
Now, caulk all around the inside edge of the sort of box you have created. A fat bead. Then put the cutout piece of t-111 back in.
Caulk again, over the two seams at the sides of the cutout, once you have put it back in.
Trim.
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hey thanks, I printed out your suggestion and will review at the job site.
You are welcome.
Signed: Bubba Hussein Obama.
What a fool believes he sees
No wise man has the power, to reason away
Click here for access to the Woodshed Tavern
The trim is 1 1/2", so with the 5/8" siding that is 2 1/8", which is not available off the shelf in z-bar. Go figure. I am contacting a sheet metal guy to have some custom made.I am considering investing in a large size brake cause this sort of thing continues to pop up. I have to learn to solder galvy metal for this job.I think the flux is muratic acid, but I do not know what the solder material is. Is it the same as with copper?
Just slip the flashing under the t1-11.
You'll need 1 1/2" flashing if the siding is 5/8". We used to do this all the time.
If you need another flashing at the window, put the proper size there too.