Roof Live Load "Promenade Purposes"

[bookowski]

Does anyone know what is intended in IBC for roof live loading under special purpose roofs where it is stated that "roofs used for promenade purposes" use 60psf live loading, while roofs "used for assembly purposes" are 100psf.

I'm looking at a single family residence where the roof will be used as a roof deck - what is the line between "promenade" and "assembly"? I can't find a definition anywhere.

 

[bookowski]

and as a follow up to my own question - when (if ever) can a roof deck be considered a deck for live loading, i.e. "same as occupancy served".

 

[msquared48]

A promenade would constitute a place for walking, as opposed to a place of assembly constituting standing or sitting. So the occupancy would be less for a promenade as density would be less.

Mike McCann
MMC Engineering

 

[AELLC]

If a balcony over 100 sf can be designed for residential live=40 psf, and a balcony < = 100 sf is designed for 60 psf, it follows the roof deck should be the same, i.e. a smaller area is liable to have a higher live load than the regular residential floor live = 40 psf.

I don't think you need to use commercial live load requirements of 60 and 100 psf respectively for promenade and assembly.

 

[AELLC]

I meant to say a RESIDENTIAL balcony in my post above.

 

[bookowski]

AELLC - Where is the 40psf for > 100s.f.? My governing code is IBC '03 and for balconies I only see 60psf for <100s.f. or 100psf for >. I agree though that using 40 seems reasonable for a single family residential - just trying to figure out if that's justified by code.

Does a roof deck fall under the category "deck" and therefore it's 40psf, or does it fall under "special purpose roof" and get a 60 (or 100)?

The term promenade is ambiguous - how often do you have a roof for strolling but are sure that no one can sit/assemble? They should define that more clearly or eliminate it.

 

[woodman88]

Per the 2003 IRC Decks are 40psf and Exterior balconies are 60psf.
I would use 60psf for residenial loading of decks and all balconies. Though some engineers do say that as the area become smaller than 100 sq. ft. people will stand closer together which is why areas 100 sq. ft. or less should be 60psf and any areas greater than 100 sq.ft. can be 40psf.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

 

[DST148]

@bookowski> Your post #2: When can a deck be considered a deck for live loading..... See if the attachment would help.