# Why Pre-cut Studs are 92-5/8″ Long

Why Pre-cut Studs are 92-5/8” Long

Growing up with my Father and six framing contractor uncles (my Dad’s five brothers and Auntie Darlene’s husband Vern) all of us male Momb cousins (myself, brother Mark, Kim, Randy and Scott) eventually became M.E.I. (Momb Enterprises, Inc.) teenage slaves. My beloved Uncle Gil even has on his Facebook profile, “Former Mean Boss at MEI”. Whilst our generation worked hard, we were generally looked upon as strong backs and weak minds – there was very little explanation as to why things were done a certain way, and lots of do it, do it quick and do it right.

In framing stud walls, Uncle Gil would give us an evil eye if we had a stud even a minute fraction of an inch off being directly between his lay out marks on top and bottom plates. Never was there a discussion of why it was we were framing with studs 92-5/8” long, when all other framing lumber came in even two foot multiples (albeit those were always ½” to 5/8” greater in length than an exact two foot).

Now an average small home takes roughly 400 studs, can you imagine how time consuming it would be to have to trim back all of these if eight foot material was ordered and 92-5/8” was desired?

It wasn’t until I went to work managing Lucas Plywood and Lumber’s roof truss plant, where I became exposed to “P.E.T.” – Precision Trimmed Lumber. This was one service provided for by our lumber remanufacturing (aka reman) operation. While there, since I was good at math, I taught members of our lumber sales team how to do material takeoffs for stick frame home lumber packages.

Helpful hint to those of your reading along at home – want studs 16” on center (o.c.)? Take lineal footage of walls and order the same number of studs as feet of wall. 24”o.c. take lineal footage x 2/3rds. Works out to be remarkably close in actual use.

Anyhow, back to why studs are 92-5/8” long.

Anecdotally, supposedly the company who first pre-cut studs couldn’t close their 1943 delivery truck’s tailgate with eight foot material – so studs were cut to fit the truck bed.

When 92-5/8” studs are placed upon a single 2x bottom plate and a double top plate, wall height becomes 97-1/8”. This allows for 5/8” drywall on ceilings and keeps wall drywall ½” above the subfloor. This gives space for drywall to expand and contract without affecting flooring, as well as from absorbing any moisture on the floor.

Even though post frame buildings, with interiors to be finished, should be properly designed using bookshelf (horizontal girts) for exterior walls, these same rules are best followed for determining floor-to-ceiling heights. By use of heights 1-1/8” greater than whole feet, material use is minimized and drywall sheets can be run vertically without need for cutting. For extended reading on why this is best: www.HansenPoleBuildings.com/2019/09/11-reasons-post-frame-commercial-girted-walls-are-best-for-drywall/.

# PET Lumber

A Builder’s PET

The stereotypical builder appears to be characterized as driving a four-wheel-drive extended cab pickup (of course jacked up so a ladder is required to get in), having a jobsite stereo system which can be heard for miles with the sound turned to only 30%, and of course – the ever faithful pet, the huge (usually slobbering) dog.

Besides the dog, there is another pet which is loved especially by framing contractors. Precision-End Trimmed lumber (known by its acronym PET) is lumber which is trimmed square on both ends to uniform lengths. The manufacturing tolerance is 1/16th of an inch over or under length in no more than 20% of the pieces.

Most often PET lumber is found in studs for framing exterior and interior walls. The most common length of PET stud is 92-5/8” which, after the bottom, top and double plates are added, gives a finished framed ceiling height of 97-1/8”. When 5/8” gypsum wallboard is added to the ceiling, two rows of four foot width wallboard can be installed horizontally on the walls without having to rip them lengthwise.

Other than for studs, unless by special order, dimensional lumber is NOT PET lumber.

When constructing his self-storage pole building, Hansen Buildings owner Eric often commented upon how inconvenient it is for framing lumber to not be cut to exact lengths.

(Begin more reading on Eric’s project at: https://www.hansenpolebuildings.com/blog/2014/06/builder/)

When purchasing a piece of two inch (2×4, 2×6, 2×8, etc.) at your local lumberyard or big box store (e.g. The Home Depot® or Lowe’s®) take out the trusty tape measure and check the length on a few boards.

Most typically proper, standard lengths of lumber are cut just a little bit longer. This extra length, generally from 3/8 to 5/8 inches, allows for proper squaring of the board. Especially with wider width lumber, it is not uncommon for one or both ends to have been cut slightly out of square when being processed at the sawmill from log to lumber.

There are times, in pole building construction, when the extra fraction of an inch makes all the difference in a board fitting or not. Frankly – I’d rather have the extra little bit to work with, than to have to go hunting for the green handled board stretcher