2x6 vs 2x4 Wood Stud Walls

[SGleason]

I am seeking TL data to substantiate (or refute) the premise that a 2x6 wood stud wall with (1x) 5/8" Type X GWB on both sides will perform appreciably worse than a 2x4 wood stud wall due to increased overall stiffness of the assembly.

I have always struggled to find good data on 6" wood stud wall assemblies.

Steve

[Soundman2020]

I just took a look, and interesting IR-761 doesn't cover that comparison! There's no 2x6 wood studs in there, for some reason... the only wood studs are 2x4s. There's both sizes for steel studs, but only one for wood.

However, 2x6 would be better than 2x4 under most circumstances.

It's not the same, but pages 27 and 33 of ir-761 have a similar comparison for metal studs: both cases is 610mm OC, type X drwyall, fiberglass insulation. The only thing that changes is the stud depth:

2x4 studs (page 33):

IR761--page-33--2x4-x-metal-610-fiber--stc45.jpg

2x6 studs (page 27):

IR761--page-27--2x6-x-metal-610-fiber--stc52.jpg

The 2x6 is STC-52, vs only STC 45 for the 2x4. All other factors being equal. OK, so that's metal studs not wood, so not really a good indicator, but the same principle should hold... I think!

You got me thinking now... I seldom design with 2x6 wood studs in walls, almost always 2x4s, so I guess that's why I don't have any data on that!

Maybe Andre has better data for wood studs.


- Stuart -

[SGleason]

Thanks, Stuart....I saw that steel stud data. Those are likely to be 18 or 20 gauge so they'll be performing like wood.

I always give out 2x4 data and tell folks it will be good minimum base data. Maybe that's why nobody tests with 2x6.

I was taken aback with a statement attributed to the head of a prominent test lab on the east coast of the US that 2x6 wood studs will perform worse than 2x4's because they make the wall stiffer. Does not make much sense to me.

Steve

[AVare]

Thanks, Stuart....I saw that steel stud data. Those are likely to be 18 or 20 gauge so they'll be performing like wood.

What data are you referring to? The pages that Stuart posted show the steel studs are 25 gauge.

Unfortunately I do not have any data on 2 x 6 wood stud partitions.

Andre

[Soundman2020]

Unfortunately I do not have any data on 2 x 6 wood stud partitions.

I'll look around and see what I can find, but I'm pretty certain that if you don't have it, then I don't have it either!

I should probably dust off my copy of the 1973 Wyle report, and see if they tried different sized studs: I don't recall for sure, but they tried a whole bunch of other stuff, so maybe they tried that too... but I think not.

- Stuart -

[SGleason]

What data are you referring to? The pages that Stuart posted show the steel studs are 25 gauge.

Ah yes....I missed that, Andre. Thanks. I have always seen 6" steel studs as thicker gauge in construction drawings.


There is an interesting prototype wall on page 150. 2x6 wood studs with (1x) 5/8" GWB on one side and (2x) 3/8" GWB on the other. The 3/8" boards are attached over pvc spacers.....STC 54.

I can use that data I think. Thanks Stuart.

Steve

What data are you referring to? The pages that Stuart posted show the steel studs are 25 gauge.

Ah yes....I missed that, Andre. Thanks. I have always seen 6" steel studs as thicker gauge in construction drawings.

Steve

[Soundman2020]

I have always seen 6" steel studs as thicker gauge in construction drawings.

There are basically two types of metal studs: those that are designed for handling structural loads, and those that aren't. Load-bearing studs are thicker steel and can support loads bearing placed on them from upper floors, roofing, ceilings, etc. Thinner gauge studs are only designed to hold up the drywall, not to support any structural loads. So you have probably been looking at plans for structural steel framing, rather than light-weight non-load bearing partitions.

- Stuart -