ss roofing bracing 1

[Tdog67]

Fellers,

for a lapped Z roof purlin does the ss roofing brace the top flange? It is screwed into the purlin and the ss roofing is not considered as a diaphragm but i believe it does brace the top flange of the purlin?

 

[Lion06]

I wouldn't count on it to.

 

[csd72]

Check the manufacturers technical literature

 

[Tdog67]

from the code it looks as if one meets the "thru-fastened" condition then the ss roofing does brace the top flange

 

[hokie66]

What is "ss roofing"? Standing seam? If screws are through the crown of a profile, they don't brace purlins well. But if they are through the valleys, they do. Valley fastening is not usual in roofs, as they diminish watertightness. If your roof is supported by clips which are screwed to the purlins, then the roofing itself slides in the clips, thus it doesn't brace the purlins.

 

[Ron]

Yes...in most cases, the standing seam roof will brace the top flange of a Z-purlin. As csd72 noted, check the manufacturer's literature, though many of them don't address the structural aspects of the the panel, other than perhaps the bending under wind load. At least you'll be able to get the section properties and compute for yourself.

 

[ajh1]

Cauton: If this is a true floating roof system, which is the typical standing seam system in large buildings, the AISI Specification mandates that it does NOT brace the top flange of the purlin unless the manufacturer has performed specific testing to prove it's capabilities. That testing will generally result in a multiplier factor against full allowables of around 0.50 to 0.70.