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The length of a 2 x 4

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Forum topic by lew posted 04-01-2008 01:05 AM 1377 views 0 times favorited 24 replies Add to Favorites Watch
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lew

11804 posts in 3570 days


04-01-2008 01:05 AM

Topic tags/keywords: walls ceiling height

OK,

I just returned from substitute teaching in the Building Constructions area at the local vocational school. The regular teacher is out for the week and I am taking his place. I thought I knew my way around the subject- at least a little. The teacher left me the subject matter he wanted taught- wall framing. Having built a couple of walls in the past, I knew the names of the wall parts and the construction details of corners, “Tees”, openings and headers. I explained that for a 2×4, 8 foot, studded wall, we normally use precuts that are 92 5/8” long. A student asked why 92 5/8” and I told her that the length was calculated to allow for the thickness of the bottom plate and the double top plate- to create an 8 foot ceiling. She did a quick calculation and said that the ceiling would be 97 1/2”- which is over 8’. Even allowing for an 1/2” dry wall ceiling and a 3/4” floor, the ceiling height doesn’t come out to 96”. I told the kids I would try to find the answer for them.

Could someone please explain this to me, so I can provide them with the correct answer?

Thanks,

Lew

-- Lew- Time traveler. Purveyor of the Universe's finest custom rolling pins.


24 replies so far

View GaryK's profile

GaryK

10262 posts in 3803 days


#1 posted 04-01-2008 01:11 AM

Well 92 5/8” + (1 1/2” * 3)= 97 1/8” not 97 1/2”.

Usually you use 5/8” drywall for the ceiling bring to total to 96 1/2”.

That extra 1/2” is at the floor which is covered by the base board. It’s to take into account any variations
that occur.

-- Gary - Never pass up the opportunity to make a mistake look like you planned it that way - Tyler, TX

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lew

11804 posts in 3570 days


#2 posted 04-01-2008 01:24 AM

Thanks Gary,

Looks like my brain and typing finger are not working. The calculations on my scratch sheet were 97 1/8” but somehow by the time they got to the finger it was changed. I see about the 5/8” ceiling drywall- I thought it was 1/2” but I guess that would sag- especially if the ceiling joist were 2’ on center and alot of insulation laying on it.

Lew

-- Lew- Time traveler. Purveyor of the Universe's finest custom rolling pins.

View Tony Z's profile

Tony Z

205 posts in 3605 days


#3 posted 04-01-2008 01:27 AM

You are way too fast Gary!! I thought this was my time to shine and be the first one to comment on something I knew the answer to. I’ll get you yet.

Lew: Ditto on what Gary said.

-- Tony, Ohio

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tomd

2117 posts in 3585 days


#4 posted 04-01-2008 01:31 AM

I thought that the studs were cut for interior walls that do not use a double top plate. Exterior4 walls use a double top plate, or mayabe they do it different in other places.

-- Tom D

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DaveH

400 posts in 3593 days


#5 posted 04-01-2008 01:34 AM

Also, if a section of floor is going to have linoleum, the framers might install 3/8” to 1/2” ply over the underlayment to raise the level up closer to the carpet level.

-- DaveH - Boise, Idaho - “How hard can it be? It's only wood!”

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DaveH

400 posts in 3593 days


#6 posted 04-01-2008 01:35 AM

Bearing walls use a double top plate.

-- DaveH - Boise, Idaho - “How hard can it be? It's only wood!”

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jeffthewoodwacker

603 posts in 3619 days


#7 posted 04-01-2008 01:52 AM

Gary and Dave are correct all interior bearing walls have to be double plated. Since square and level are relative terms in house construction there has to be some “give” space along the floor lines.

-- Those that say it can't be done should not interrupt those who are doing it.

View Tony Z's profile

Tony Z

205 posts in 3605 days


#8 posted 04-01-2008 03:07 AM

OK. All walls are normally double-plated, load bearing or not. That’s what pre-cut studs are for. It eliminates the human error factor in cutting hundreds of studs and allows all of your walls to be exactly the same height. Also, the double top plate ties all the walls together because they over-lap the adjoining walls.

Side note: You can also get pre-cuts in lengths of 104 5/8” for 9’ walls.

-- Tony, Ohio

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Betsy

3391 posts in 3711 days


#9 posted 04-01-2008 03:13 AM

Dag gum it – I actually knew this answer.

-- "Our past judges our present." JFK - 1962; American Heritage Magazine

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RAH

414 posts in 3692 days


#10 posted 04-01-2008 04:02 AM

Excellent question and excellent answers. I look forward to the home improvement site Martin is working on.

-- Ron Central, CA

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Grumpy

23110 posts in 3666 days


#11 posted 04-01-2008 10:14 AM

Ahhh, I am glad I use metric.

-- Grumpy - "Always look on the bright side of life"- Monty Python

View northwoodsman's profile

northwoodsman

242 posts in 3561 days


#12 posted 04-01-2008 06:03 PM

I was taught almost 30 years ago that the reason for this stud length was that you didn’t want the drywall to touch the floor. Since you install the ceiling first, then the top section of the wall goes up (horizontally) against the ceiling, the bottom section goes up last. The gap on the bottom serves many purposes – 1) if the floor moves it could cause the drywall to crack or bow in the middle; 2) if the installer has to force in the sheet, it will bow in the middle and pop nail heads or screws heads later; 3) it allows you to put a wedge under it to raise it up tight to the top sheet (the wedge is on a pivot and you use your foot to raise the sheet); 4) it prevents the drywall from acting as a wick; 5) it gives the flooring installer a little extra room to tuck in carpet; 6) it allows you to do a better job extracting dust and debris before flooring is installed.

-- NorthWoodsMan

View F Dudak's profile

F Dudak

342 posts in 3625 days


#13 posted 04-01-2008 07:24 PM

What happened back in the day when a 2×4 was a 2×4? Hmmmmmmmm! Framed houses for 20 years so I realize that measurement may have changed over the years. It would be a good history lesson.

-- Fred.... Poconos, PA ---- Chairwright in the making ----

View GaryK's profile

GaryK

10262 posts in 3803 days


#14 posted 04-01-2008 07:31 PM

So Grumpy, does this mean that you use a 2352.675mm stud rather than a 92 5/8” stud?

-- Gary - Never pass up the opportunity to make a mistake look like you planned it that way - Tyler, TX

View Earle Wright's profile

Earle Wright

121 posts in 3535 days


#15 posted 04-01-2008 07:53 PM

When I saw that “length of a 2×4” title, I thought you’d be relating the story of the man who goes to the lumber company and says ….....

“I’d like to buy a 2×4.”

The clerk says, “How long do you want it?”

To which the man replies, “Hell, I wanna keep it !”

-- Earle Wright, Lenoir City, Tennessee

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