Minimum Live Load on Canopy per ASCE 7-02

[dozer]

It was recently pointed out to me that ASCE 7-02 requires a minimum live load on a canopy of 75 psf. To be precise, in Table 4-1 under "Occupancy or Use" it says "Marquees and canopies" and then list 75 psf as the minimum uniformly distributed load.

First of all, what is their definition of a canopy? I'm imagining a "roof" that juts out over exterior door(s), usually cantilevered, with or without rods or cables tieing the outer edge back to the building.

Second, does anyone know what there reasoning is for this? It seems to me that, if my definition is correct, a canopy is just a type of roof and the highest the minimum roof live load can be is 20 psf. So why change the rules for this special kind of roof?

 

[WillisV]

IBC 2000 also has the "Marquees and Canopies" heading under Table 1607.1 for 75psf. There is however a provision for "Awnings and Canopies" under 1607.11.2.4 which allows a 5psf live load. Obviously there is a disconnect here. In the IBC 2003 the wording under the table was changed simply to "Marquees" while the provision for "Awnings and Canopies" was left as is.

It seems then that the original canopy inclusion under 75psf was an error and that the 75psf marquees load applies perhaps to built up staging areas under tents.

 

[dozer]

Thanks for the info, Willis. Any idea if someone at ASCE can confirm that this is an error?

 

[WillisV]

Considering the wording was changed in IBC 2003 it almost certainly was, however if you want an official statement you would need to go through ICC (if you are a member you can ask at

http://www2.iccsafe.org/cs/interps/).