Installing Corrugated Metal Roofing

[Arkansas COB]

Does anyone know if it really matters if the purlins are mounted on top of the trusses or between the trusses flush with the top edge when installing corrugated roofing panels ?

Is it just an easy way to put the purlins down or is there a structural reason ?

My loafing shed has the purlins on top of the trusses but Im wanting to add a leanto off one end and it will be a little easier to make it come out right if the purlins are between the trusses.

Thanks
COB

 

[1953mercury]

Spanning the trusses with the purlins will be intrinsically much stronger than piecing them in-between. Mike

 

[kbs2244]

Without a snow load concern I think you will be OK
It will give you more surface to fasten to.

IMO they put them across the top for ease/speed of construction.

 

[6768rogues]

I have seen it done both ways, and I am in snow country. In between needs more substantial fastening.

 

[JoeMcGov]

Wind upload (trying to pull/**** your roof of the structure) is a consideration in addition to the gravity loads of snow.

Me? I'm running my purlins on TOP of the trusses. And fastening them to the trusses appropriately.

 

[readhead]

Are we talking steel or wood?