Stair & Corridor Live Loads

[prsconsultant]

Do you generally use 100 psf unreducible live loads on corridors and stairs or use 100 psf reducible LL?

 

[twinnell]

stairs - unreducible
corridors - most of the time we use unreducible. IBC says corridors in assmebly occupancy is unreducible. Also, offices have 80 psf load for elevated cooridors.

 

[LowLax]

IBC 1607.9.1.1 Says that you cannot reduce live loads that EXCEED 100psf. And 107.9.1.3 Says that live loads of 100psf or less shall not be reduced in "public assembly occupancies".

I think you can interpret that as allowing a reduction as long as the area you are considering is not classified as "public assembly". I'm not sure how you would get 100psf that wasn't public occupancy though. I wouldn't reduce it unless you have a really good reason and can back it up.

 

[JAE]

Usually stairs/corridors are small enough that the amount of reduction is pretty small so I don't bother with it.

 

[SlideRuleEra]

In addition to the 100 PSF uniform load, ASCE 7 also requires a 300 lb. concentrated load (distributed over 4 sq. in.) on each tread. I have always assumed that this concentrated load in NOT concurrent with the uniform load.

http://www.SlideRuleEra.net

 

[WillisV]

Corridors serving private residences or hotel rooms can be designed for the same live load as the occupancy that they serve. This has been discussed and argued vehimently on this site before; however, that is what the code says and IMHO it is certainly acceptable.

 

[JKW05]

ASCE 07 Section 4.3: "Floors ... shall be designed to support the uniformly distributed live loads or the concentrated load ... whichever produces the greater load effects."