# 16" on center framing spacing corner - optimize for butt- vs by- wall, interior vs exterior panels?

newbie framing question here. Haven't done any framing myself yet but I'm planning to do some and educating myself. This is a pretty theoretical question so all theoretical or practical experience is greatly appreciated. Pretty sure I'm going to get a lot of people saying I'm overthinking this, but that's ok, I'm curious :).

Most references I see for from say to space studs 16" on center. In the simplest case the first (2x4) stud is placed butted up against the end of the plate. All subsequent studs are positioned such that their centers line up with the 16", 32", 48" etc. marks on the tape measure along the plate.

Note that because of the thickness of the studs the space between the first two studs is actually 15'-1/4" = 16'-3/4", where 3/4" is half the thickness of a 2x4. This configuration ensures that when a 4'x8' panel is installed on the frame the panel will overlap a stud on both ends.

This story pretty much makes sense to me. My question is about how the story changes when you consider two walls butted up against each other and want to optimize both internal and external panels (such as interior sheetrock and exterior siding).

If you follow the prescription above I think you get the following result:

Here the wall on the right is a "by-wall" or "through-wall" in that it goes through to the end of the structure and the bottom wall is a "butt-wall" in that it butts up against the "by-wall". The studs are spaced exactly as above, 16" on-center. The only addition is a "nailer" stud on the through-wall near the corner so that there is something to which to attach the interior paneling. For reference the interior panel is drawn 1/2" thick and the exterior is 3/4", but this could of course vary and that might affect some of the dimensions I've shown?

However, we can see that not all of the panels line up with studs. The big problem is that the interior and exterior panels come to very distances along the walls. For the butt-wall at bottom the exterior paneling is shifted right of the interior paneling because it has to overhand the plate on that wall by at least 3.5" to enclose the edge of the through-wall.

Now, by adjusting the distances labeled A and B we could make it so that the fourth stud along either wall lines up with either the interior or exterior paneling as we desire. As I've shown it the interior panel lines up on the butt wall and the exterior panel lines up on the through wall. But if dimension A was decreased by 3.5" for the width of the through wall plate + the thickness of the siding, then both exterior walls could be lined up. Similarly, we could increase dimension B so that the interior panels line up on the through-wall.

Explicit questions:

• Are the two drawings I've given above decent depictions of a basic frame and framing at a corner?
• Is the trade-off between lining up for interior vs. exterior paneling actually encountered practically? If so, are frames optimized for interior siding, exterior siding, or, is 16" on center (relative to the end of the plate) always maintained so that you sometimes find things lining up for either external or internal panels depending on the type of wall and particular details?
• I've shown the interior panels (say sheetrock) butting up in a particular orientation at the corner. Is this accurate, does it really matter at all for this question? Likewise for the siding.
• I've depicted a "California corner". I know there are other types of corners and perhaps the story may change if a different corner type is used. If someone is interested they could shed light on this as well.

I’d keep the exterior side of stud spacing at 16” module and let the interior adjust as necessary. There’s two reasons for this: 1) cost, and 2) appearance.

1. Cost: You are installing the more expensive materials on the exterior (and you’re probably installing two layers: sheathing and siding). The material (gypsum board) inside is relatively inexpensive and can be trimmed easily to fit unusual spacing.

2. Appearance: When you patch in small infill pieces at edges it looks unplanned and unsightly.

Summary: Start from the corner and measure out 16” to the center of the first stud, then continue at 16” on center. That way you’ll use a full sheet of sheathing at the corner. Often contractors will measure out only 15 1/2” so the siding laps good at the corner too and covers the sheathing.

• Would you say that what you describe (essentially reducing dimension "A" on the drawing in the question) is standard practice when framing exterior walls? Commented Jun 29, 2021 at 22:49
• @Jagerber48 Yes, it is standard practice where I live (far western U.S.) Commented Jun 29, 2021 at 22:57
• "On center" is roughly the same as "on edge" -- I hook the measuring tape at one end of the wall, say the left end, and mark left-edges (not centers) of studs at 0, 16, 32, etc. Likewise for a wall laid out from the right end: mark right-edges of studs. I use an X or other mark to remind myself to which side of the line the stud should be placed. The same 16" interval is achieved and I avoid the trouble of center-aligning the stud at each mark. Commented Jun 30, 2021 at 18:00
• @Greg Hill If you align the side of the stud with your marks at 16”, 32”, etc., how do you fasten the next sheet of plywood without adding another stud? Commented Jun 30, 2021 at 18:06
• @LeeSam I shift the sheet of plywood by a half-stud! It has the down side of leaving a half-stud-width exposed at the beginning end. To avoid that, offset the tape measure when laying out the stud position marks. I'll write an answer with more detail. Commented Jun 30, 2021 at 22:40

Like Lee Sam, I'd frame in a way that optimizes for placement of the exterior sheathing. It is usually placed oriented vertically, ie 48" wide whereas drywall is usually placed horizontally, ie 8/10/12 feet wide. It just makes more sense to shorten sheets of drywall (they're all going to need to be cut anyway) rather than to cut the sheathing narrower.

I approach wall layout based on measuring and marking for stud edges so that I don't have to spend time/thought trying to center things.

My drawing below starts out like yours. I'd frame that right-hand wall first by doing the following:

1. Stand the top and bottom plates on edge, laid side by side. This is depicted by the rectangles and dimension lines along the right-hand edge of the drawing.
2. Measure off the corner -- but offset the measuring tape 3/4" beyond the end of the plates. This is half the width of a stud. It makes the first bay a little narrower and pulls all the studs in that wall 3/4" closer to the corner. I do it so that the first sheet of plywood can align flush to the lower end of the wall and centered on the 4th stud.
3. Working along the two plates (from bottom to top as depicted here) I mark off the edges of the studs. The near edge of the first stud goes right at the 16" point on my tape measure. I place my framing square so that its 1.5" wide leg lays across the two plates, align its edge to the 16" mark on my tape, and with two swipes of the pencil mark the two sides of the stud. Repeat at 32", 48", etc.
4. Separate the plates, nail the studs in place, nail on the plywood, stand the wall up and brace it.

My drawing differs from yours in the second/lower wall: I make that right-most stud bay extra-narrow so that the corner and the rest of the wall come together nicely.

Before drawing anything I think about how I want this wall to fit with the first wall. At the right-hand end of this wall I want a full 48" wide piece of plywood to be flush to the exterior face of the first wall. I also want the left-hand edge of that first sheet to fall on the center of a stud. I'll need to offset my measuring tape to account for 0.5" of sheathing thickness plus 3.5" of stud thickness plus 0.75" of half-stud width: a total of 4.75". I might cut a scrap block of 2x4 to that size and use it as a spacer (this house or whatever I'm framing will have at least 4 outside corners; I'm going to need this same offset for every one of them!) or I might just clamp the tape to the pair of wall plates at that offset.

Top and bottom plate layout is as before:

1. Offset the measuring tape
2. Place a stud flush at the end of the plates
3. Next stud goes with its near edge right on the 16" mark on the tape; draw the lines for both sides of it using the framing square
4. Carry on down the wall.

Assembly is a little different here. I might omit the first piece of plywood, stand the wall in place, and then nail on the first piece of plywood from the outside. Or, if there's room to work and the wall isn't going to be too heavy, I'll push it 6 inches to the left, build it with the first piece of sheathing attached, stand it up, then bump it to the right until the gap is closed.

I struggled with the same problem so I just laid out studs 16”o.c. To work with drywall. Then on exterior I just pulled the first piece of sheathing back 3 1/2”. Then it lined up and I just ripped a 3 1/2” piece of sheathing for corner since it would be covered with a vinyl siding outside corner and you would never know!!! Good luck