load bearing wall stud spacing

[NMRKen]

Here is the question, I have a wall that is 22' long and 11' in height. perpendicular to this wall is another floor, it has 2x12 joist that are 12" on center. The joist over lap and have lengths of 13' on one side and 16' on the other side. Assume that far ends are properly attached/constructed.
now the wall was designed as 12" on center but built 16" on center, how would this effect the load capacity of the floor above?

 

[JAE]

Is this your house?

 

[r13]

I think you need to talk to the designer to see whether this is acceptable, or remedial action is required.

 

[NMRKen]

I have a call into the designer but no reply as of yet. This is in a light commercial property I own.
as a note on the description, this is free standing inside a tall building, so no roof loading on 2nd floor.

 

[r13]

I wonder why the designer has designed the wall with studs spaced at 12" oc, while 16" is the norm (seems to me).

 

[sdz]

I assume that the wall was designed with studs at 12" crs to match the joists over. If it's been built with studs at 16" crs then the joists won't match the studs and the floor load has to be transferred by the top plate in bending and shear. The worst case scenario is that the joist load will break the wall top plate. The builder might need to put nogging in under the top plate to support the load.

 

[Tomfh]

There’s not a straightforward answer. Studs matching joists is obviously better, but for constructability reasons it’s common for the joists to land where they land and the plates span back to the studs.

You need to check with the designer in this case.

 

[dik]

Because of the height or load, you may need them at 12"...


Dik

 

[r13]

dik,

OP said the wall is 11' height, and the structure is inside of a building without roof load. Quite suspicious on the requirement. But there is possibility of long span...

 

[NMRKen]

This was adding a mezzanine inside a building, it is free standing. That is why no roof load above. The none bearing wall side of the joist are each on 3 6x6's capped with a pair of 12" LVL. The plan details show the joists over each stud. but this may just be have it was drawn as it is not noted anywhere in the plans that this is the case.
The designer is friends with the contractor so so I may have to take anything I get from him with a grain of salt.
I am not after an absolute answer, just an estimate, something like the floor loading is reduced by 20-30% or such

 

[r13]

My bold call, R = [1-(12/16)]*100 = 25%.

Please bear in mind, reduce load capacity of a structure is a dangerous proposition, as someone may not aware the restriction.

 

[HouseBoy]

IF the wall is built with a double top plate (which should be standard for a load bearing wall) THEN I doubt that there is a problem with the fact that the joists are at 12" spacing and the studs are at 16" spacing (assuming I understand the layout correctly).
It's true that there would be a simpler load path if the joists and the studs align but that is not necessary as the double top plate will normally be capable of carrying the load to the studs in "flat-ways" bending.

 

[jayrod12]

If it's a mezzanine, it may not support the roof, but if it supports storage loading, i.e. 100 psf, then studs at 12" o/c at that height might be required. Or the double top plate may not have the capacity to span between studs. 2x4 or 2x6 studs?

 

[HouseBoy]

JR12 - You're right, mezz loading and 2x4 vs. 2x6 will make a difference. Species and grade will affect the capacity also (obviously).
Maybe it's NOT so good. 2x4 wall, probably not good. 2x6 wall, maybe close or overstressed (depending
Flat use bending is only about a 10% increase in bending allowable.

Also, stud capacity is a separate consideration from the plate design.

OP - do we understand the framing configuration?

Maybe post a pic?

 

[dik]

Missed that... that will teach me to skim...


Dik