Interior Wall Out-Of-Plane Load 1

[XR250]

I have a residential shower with the two surrounding walls stopping a few feet short of the ceiling. The walls do not attach to each other and one end of each wall is attached to an exterior wall. As such, one end of each wall is unbraced. I want to cantilever a 3 1/2x3 1/2" steel or engineered wood post up from the floor system below by sandwiching it between some joists (all new construction). When designing the cantilevered posts and subsequent moments in the joists, what would be a reasonable loading to apply to the post. If I simply use 5 psf on the shower wall, I only get a 35 lb. reaction at the top of the post. Does this seem like a reasonable design load? I could imagine some antics in the shower that might require higher design loads :>

 

[EngineeringEric]

Shower antics usually cause more loading than 35 pounds, and i have to say i like where your mind is first thing in the morning I think you will need to load test what ever you design and do lots of research

You could use a handrail assumption and use a 200# or 50plf but this will make it rather large. the steel is probably excessive since your base will be so flexible and Engr. Post i worry about the environment. I am guessing there is no way to have a transverse girt at the top of your cantilever to make your walls Simple Spanning??

 

[XR250]

Yes, I think testing might be in order.
The girt would interfere with the aesthetic as the Arch wants the walls unattached over the shower entry.
50 plf at guardrail height would translate into about a 50 lb point load at the top of the post as would a 200 lb point load at guardrail height (each wall is 4' long x 7' high). I think I will go with that. Looks like a 4x4 PSL post has too much defection. I guess HSS will be req'd

 

[manstrom]

Guardrail loading would be a reasonable starting point. 200# at 42"

 

[KootK]

Guardrail loading seems excessive to me. I vote for 50 lbs at 42" with deflection being the parameter of interest. I studied something similar for deflection requirements on flimsy architectural handrails. It would take a pretty extreme situation for two people to generate 200 lbs of lateral force.

The greatest trick that bond stress ever pulled was convincing the world it didn't exist.

 

[jwilson33]

I'll vote for the 50lb point load at 42" too, but add in the caveat that someone should give it the boot test (or butt test) when it is rough framed. If it feels very rigid, and the fasteners are such that it shouldn't ever loosen, then go with it. It will only stiffen once it is sheathed and tiled, not that that technically helps any.

 

[BAretired]

If two guys are horsing around in the shower, I would expect a horizontal force to occur at a higher elevation than 42". I would suggest a lateral force of 100# at 60".

If two little old ladies are using the showers, that may be a tad excessive.

BA

 

[CELinOttawa]

BA's right... Everyone else on the low end of this shinanigan-worrying had me until we consider that we cannot discriminate. There could be two quite large men owning this house in the future, and that's a smashed-glass-bearcapade waiting to happen.

Pardon me while I go be sick... *sigh*

 

[wannabeSE]

Someday, grab bars might be installed in the shower and they should be designed for a 250 lbs in any direction (ASCE 7-10 §4.5.2; 2012 IBC §1607.8.2). Residential requirements may be different.

 

[XR250]

Geez, how would a grab bar get 250 lb lateral load in the shower? - unless those big men get real creative :>

 

[mike20793]

I agree with wannabeSE. Use that load and then use engineering judgement to see if the design is reasonable. If it isn't try to find some way to reduce the load (research, testing, etc.). 250 lb in any direction doesn't seem like that much load when you think about inertial effects on mass (someone falling and actually grabbing the bar as they fall).