Drywall moves 7/8" OFF O.C. w each layer of drywall?

In detail the following is my convoluted thinking which leads me to think starting OC measurements at 1’ 11 1/4” for outside corners OR 2’ 2 ¾” for inside corners (depending on if measurement is taken from inside or outside corner of frame itself) is NOT a good idea. Benefit of this would be a few less cuts of full pieces of drywall, less waste. With the standard OC measurement you would waste a few pieces to make up 5/8” or 7/8” overlaps/BUMPS. This same method of thinking has me wondering about all other wall coverings (sheathing, etc....) and 1st stud measurement of OC from 1 of the 2 walls at a corner. I realize disputing standard OC measurements method may sound absurd, but it’s my own time I waste. Also fully well realize 2nd and 3rd layers of drywall for our purposes (sound iso) do not apply hear (we’re going to skip stud bays), I’m only pointing out in drawings a variance in 1st layer. Starting with outside corner. Rod’s Corner detail posted earlier on this thread: Now, just the 1st layer of drywall: Note I’m not including ¼” backer rod and caulk in above drawing. * Frame built, carefully measured from outside corner of frame 1’ 11 1/”4 first stud location and then each stud, 24” on from there to get the 8’ stud position at 7’ 11 ¼” * Drywall installed on Frame A, no problem. * Drywall installed on Frame B and we end up with the drywall seam 5/8” away from the center of the 8’ stud. But I did not include the ¼” for backer rod and caulk so it would really look like this at corner: Then our 8’ stud would have the seam a little bit more centered as: What could we do at this point ? 1. Just install drywall seams a bit off center of stud. 2. Start drywall on 6’ stud of frame B, cut and (maybe) waste some drywall. 3. BUMP our 1st OC measurements on Frame A to 1’ 11 ½” (making up for ¼” of backer rod and caulk) and for Frame B to 1’ 10 7/8”, so that drywall seams at the 8’ stud will land in center of stud: OR 4. We could start the OC measurement from the other end of the wall… but does other end of wall meet an outside or inside corner? Also to be noted, chances are the walls length is not going to be a multiple of 24”, so one end stud bay of the wall will be less then 24” wide. Drywall (or wall covering) will have to be cut to fit… and again the point of my rambling: why cut a piece at both ends of the wall? Let’s look at the inside corner. * In above pic I’ve not included the ¼” for backer rod and caulk. * OC measurement starts at 2’ 2 ¾” from outside corners of frame. * Again the drywall seam at 8’ stud lands far from the center of stud. THEN add in ¼” backer rod and caulk: Now in above, the seam lands 1/8” past the 8' stud. So I would propose this: * The wall which gets drywall 1st (up and down wall in my above pic), 1st stud gets placed 2’ 3” from outside corner of frame. * The wall which gets drywall, 1st stud gets placed 2’ 3 5/8” from outside corner of frame. * All studs follow plus 24” each, putting the 8’ stud at 8’ 3 5/8”, so the drywall seam lands in the middle of stud. :idea: Call me cheap and lazy to not cut 4 or 6 pieces of drywall for my own room. :roll: Who knows how many peices this could work out to in a larger multi room build. :idea: Call me crazy, most of us will have so many angled/splayed walls OR walls that are not over 8’ (or 10’ or 12’) long that this even matters :shock: BUT I think this is a valid thing to point out. :twisted: I can’t remember exactly how I measured the 1st studs in the 2 walls I have built (figured numbers out on scrap paper and threw away :oops: ) BUT I did take all of the above (and ½” drywall on existing wall) into consideration and built my walls accordingly. My 1st layer of drywall seams all landed on a center of stud 8) .... and I've still found lot’s of other things to complain about when intsalling drywall. :twisted:

Drywall square, utility(razor) knife, box of blades, surform/GB knife/rasp, Rotozip, dust masks, someone ELSE to do the work ... Steve

I'm not annoyed enough yet and have no faith to hire someone else. Marc :roll:

If you think figuring all this out is annoying, try explaining to a "normal" drywaller why he can't just stuff things in between inner and outer frames, or leave out caulk, or put the second layer up without mudding the first because "it won't show anyway"... :twisted: Oh, and I now fully believe you; you really ARE anal :lol:

guitardad72 wrote:

In detail the following is my convoluted thinking which leads me to think starting OC measurements at 1’ 11 1/4” for outside corners OR 2’ 2 ¾” for inside corners (depending on if measurement is taken from inside or outside corner of frame itself) is NOT a good idea.

Marc, You asked a question that I answered in accordance with industry standards. No one in the world trys to layout walls (especially multiple layer walls) by trying to figure out lap conditions. If the first lapping sheet has to be trimmed by 3/4" - then trim it- you'll find out that (seeing as you are going to have to cut all subsequent layers to fit anyways) that the effort you are putting into this is much more than the work of trimming a sheet of drywall. That plus - if you trim by a bay the waste is always eaten up somewhere else. And a 1/4" trim is meaningless - it's a quick zip with a utility knife. As a matter of course - when I construct buildings - the interior studs layout in concert with the exterior walls - the exterior walls are laid out for sheathing fit - from left to right (facing the front of the building) and front to back. Thus all inside drywall has to be cut for the first sheet anyway. I follow this throughout the building with even my non-bearing wall assemblies. This way I can walk into any building I built at any point in time in my life - and tell you exactly where each and every framing member is. No - it isn't industry standard to layout walls the way you're thinking of doing it - which is why you would never see those dimensions in any of my sketches. Sincerely, Rod

Rod, Thanks, I'm done with this topic now.

the effort you are putting into this is much more than the work of trimming a sheet of drywall

Yes, when there is a choice between doing more and less work to complete a goal in general, less work is better... even though my instinct always tells me the hard way will achieve a better result and I'm not a fan of the "easy button". Thanks for going to the end of this with me :D Marc