best purlines orientation 1

[lolobau]

Hi

I would like to find out what is the best orientation for Purlin fixing?

lets say for example lipped channels fixed on a roof with 20 degree slope

should they be open to the top or bottom? see attached image

 

[hokie66]

Mike,
That would be true for you as well, but bent you are.

 

[Agent666]

At KootK, yes basically do the same job at laterally restraining the section, but a much better job at torsionally restraining the section.

See attached link for a picture labelled fastbrace

Link