Anyone seen this framing technique before? Trusses are set and then the sheating is started at the peak and filled in to the bottom. I’ve seen a couple different builders do this and don’t understand the logic.No dormers, no fill in to form a valley, just a straight run. Both times the roofs were 8/12 or better.
I’m no framer but I have framed a number of homes. We always start at the bottom. Straighten the tails with the sub fascia and work from the bottom up aligning the truss spacing as needed as you go up. Am I missing something here or is top down a common practice?
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We do that maybe half the time.
When the roof is steep, you need to work off toeboards. So when you frame, you are putting on brace strapping anyways. We use 2x4 to brace off the framing and then can walk them to sheathe from top down, removing the toeboards as we go. if you work from bottom up, then you have to both remove bracing and add toeboards as you go.
Another advantage is on a complicated roof ( which isn't the case as you report) you can have some shelter to hang tarps over when it looks like bad weather and several days to get dried in.
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I guess you do what you are comfortable and familiar with. We use the metal truss spacers ( the kind you can sheet over the top of) during the truss setting and then run 2x4s on the inside of trusses per engineers specs. We then set sub fascia, straightening the ends as needed, and sheet up. After first row of sheathing, we then put down toe boards to work off for next row etc. The toe boards stay on to hold the shingles, felt etc. and come off as we shingle up.
We also use the ply clips between each seam. I can't imagine using clips in top down, especially with a toe board in the way, you wouldn't be able to slide the lower sheet up into place. We do this with one guy on the ground cutting and handing up panels and one or two guys on the roof. It just seems safer to me to have something stable under my feet while moving 4x8 sheets around the roof. I see myself slipping off a toeboard with sheathing in hand and landing crotch first on an open truss web!
Ouch!
We don't use trusses - stick frame only, and at 16" oc with no clips.
shhh. Don't tell boss Hog on me.
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Your approach would make sense to me with rafters, but these houses were trussed. Anyone else seen this done with trusses?
I don't think I would want to start at the top . But I have measured up 48" and started there and went up. That way I could work off the top plate .
That's similar to what I do. I start by figuring out what the eventual rip is going to be. I snap a line that far up from the tails or that distance + 48".... whichever will be easier to see. Stand on the top plates and git going. I then throw the rip on when I'm standing nice and comfy on wall brackets running the trim.
I went this route sheathing my detached garage (8/12 pitch). I was working alone and it was easier for me to set the top sheets first because I could use the trusses along with planks as a platform to stand on. It would have been harder for me to carry full 4X8 sheets up a ladder, onto existing sheething and up into place. In my area, we don't use clips, we have to back every plywood joint with 2x blocking, so the clips were never a problem.
How big was your roof and how did you get the sheets up to the peak by yourself?
The whole roof was 8/12 pitch, 25' long spanning 24'. I used attic trusses, so I put a sub-floor in the attic portion first, then staged the sheets in small groups there. I marked my 24" centers on the sheathing before putting it up. I'd put the sheet on its side, slide it between two of the trusses, then lift it to verticle. Then I'd pick and angle it up, then twist it around until it was laying on the trusses. This wasn't too hard as I had something solid and level to stand on, namely the attic floor as well as planks laid down on the truss bottom chords. I ran horizontal chalklines before all this along the trusses and put a couple of nails along it for the sheets to rest against. Then I was free to fine-tune the sheets/trusses as required to maintain my 24" centers. The last few sheets on the end were tricky as I couldn't slide them from the attic space outside, so I used some scaffolding and manhandled them into place. These were mostly 4'X4' pieces though, so it wasn't too bad.
All in all, it was much easier than trying to haul them by myself up the angled portion of the roof.
Hope that helps!
Andy
Okay. Rafters(piffin) and storage trusses with a floor to work from. But standard trusses 24" oc, straight runs, crew of guys, top down .I still don't get that.
Yeah, if I had a crew of guys helping me, I wouldn't have gone top-down. It was just easier logistically working alone.
I don't like the idea of top-down sheathing much.
Seems to me you're adding a lot of weight on top of largely unbraced rafters or trusses. And you're adding a lot of square footage of plywood that's more or less a big sail up there.
I've never heard of a partially sheathed house blowing down under these circumstances. But the idea bothers me a little.If builders built buildings the way programmers wrote programs, then the first woodpecker that came along would destroy civilization.
I agree
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I have never framed, so this is a question of ignorance, not argument...
a lot of weight on top of largely unbraced rafters or trusses. Wouldn't the first sheet or two of ply add a lot of bracing to the rafters?
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The plywood would definitely add some rigidity as soon as you started nailing it down.
But if the trutses were large and the top chord was really long, it may not be enough.I feel on edge lately. A little like a hemophiliac in a porcupine petting zoo.