For those who have installed metal roofing on a gambrel/barn-style roof, any tips you can share on how best to install the horizontal gambrel trim?

[Studly]

I'm installing exposed fastener metal roofing from Menard's on a large gambrel-roof shed for the first time. Have the lower panels installed and the lower rake trim installed. Now I have to do the horizontal gambrel trim piece, as shown in the image above, that goes between the upper and lower sections of the roof. Unlike on that image, however, I'm installing it on plywood sheathing, not purlins. Have a few questions on the best way to install this gambrel trim:

1. When you have to overlap the gambrel trim horizontally end to end, like I will need to do, is it important to cut out the hem of one piece when underlapping it with the adjacent piece, as shown in this video? Or do most people just underlap and caulk 'em together without any cutting of the hem?
2. When you run the top metal panels down and over the gambrel trim, do you usually leave the bottom of the panels overhanging the break in the gambrel trim by an inch or so, as shown in the diagram above, so it's kind of like having a drip edge? I've seen other installation diagrams showing the panels running down to the break in the trim but not overhanging it.
3. In my case, I'll need to overlap two pieces of the trim end-to-end to go the length of my shed roof. Is it easier to overlap and caulk them on the ground and let it dry before putting both up on the roof at the same time? Or is it easier to put one section of the gambrel trim up at a time and overlap and caulk them on the roof?
4. Any other advice or tips on installing gambrel trim?

 

[trashyman]

Overlap them a foot with the overlap facing away from most of the weather and call it a day. No different than a ridge cap. I've never caulked them and had it leak. You could do it for your own piece of mind. I'd let the roof metal hang past an inch or so if it were me.

 

[Studly]

Overlap them a foot with the overlap facing away from most of the weather and call it a day. No different than a ridge cap. I've never caulked them and had it leak. You could do it for your own piece of mind. I'd let the roof metal hang past an inch or so if it were me.

Thanks much for the advice! So you didn't mess with cutting the folded over hem off one, and bending out the other that it fits into and compressing them together where they overlap, right? I imagine they recommend that in the video I linked to above mainly so it looks better and doesn't look too thick where the trim overlaps, but doing that may not be worth the work if it's not that noticable anyway.