Wind Loads on Roof Mounted Structures

[ToadJones]

I do not have my ASCE & here with me and was wondering if there is a section in the code for wind loads on roof mounted structures.

I am not designing the MWRFS or the C&C.
I am strictly asking about the loading on the roof mounted structure itself.
Do you treat this as an independent structure that is simply at some elevation in the air and approach it that way?

 

[JAE]

I'm not at the office right now - but I think, if your equipment is less than 700 s.f. you'd use C&C loads - I think there is a section for equipment/tanks etc. If more than 700 psf area then you'd use the MWFRS wind loads as though it was a part of your building at its actual elevation.

 

[HuckleberryFinn]

Toad,

I think it would depend on what you were designing. If your talking about some solar panels mounted to the roof or a small satellite dish I would probably check the Wind of a Sign loads and compare it to the components and cladding loads and use the more strict of the two. Mechanical units, I would probably utilize the same methodology.

ALTHOUGH, If I remember correctly, the new ASCE-7-10 code has a few sections that pertain directly to rooftop mounted equipment....

Hope this helps,

-Huck

 

[ToadJones]

Thanks for the input gents

 

[Ron]

TJ...specific provisions as follow, depending on the size of the rooftop structure...

[highlight]6.5.15.1 Rooftop Structures and Equipment for Buildings with h ≤ 60 ft (18.3 m). The force on rooftop structures and equipment with A f less than (0.1Bh) located on buildings with h ≤ 60 ft (18.3 m) shall be determined from Eq. 6-28, increased by a factor of 1.9. The factor shall be permitted to be reduced linearly from 1.9 to 1.0 as the value of A f is increased from (0.1Bh) to (Bh).[/highlight]

(excerpt from ASCE 7-05, "Minimum Design Loads for Buildings and
Other Structures", American Society of Civil Engineers, copyright 2006)

 

[JAE]

Ron - working today? (perhaps your office at home)

 

[Ron]

JAE...yeah....pretty busy right now. Have a few deadlines to meet and have to be in field two days next week for "destructive observation"!

I'll call you on Monday regarding our previous discussion....sorry couldn't get to it this week.

 

[ToadJones]

Ron-
Thank you....I guess Ill have to shoot over to my office and grab ASCE 7.
Thanks for narrowing my search...I really appreciate it.

(working from home not all its cracked up to be....I never have what I need and cant really afford duplicates).