receiver channel / c purlin questions

admin

I have built several steel structures and they were all larger and used I beams for the rafters and c purlins. I am building a small 10x10 deck with a roof and it was suggested to me to use receiver channel for the rafters and just attach the purlins to them. I am framing the roof structure and the framing for the deck itself out of steel and will just use wood decking. To me receiver channel seems weaker than the same sized c purlin. It doesn't have the extra vertical pieces present on the C and it is the same thickness (14ga) and height. If I am attaching my columns to the receiver channel and then attaching all the purlins to the receiver it seems the maximum load will be put on the receiver which is the weakest. With steel prices cost is certainly a factor but I don't want the thing collapsing. Should I use something like I beams or heavy channel iron for the rafters or will this receiver channel be fine?
Reply:Please post a drawing on what you doing.Dave

Originally Posted by bdog

I have built several steel structures and they were all larger and used I beams for the rafters and c purlins. I am building a small 10x10 deck with a roof and it was suggested to me to use receiver channel for the rafters and just attach the purlins to them. I am framing the roof structure and the framing for the deck itself out of steel and will just use wood decking. To me receiver channel seems weaker than the same sized c purlin. It doesn't have the extra vertical pieces present on the C and it is the same thickness (14ga) and height. If I am attaching my columns to the receiver channel and then attaching all the purlins to the receiver it seems the maximum load will be put on the receiver which is the weakest. With steel prices cost is certainly a factor but I don't want the thing collapsing. Should I use something like I beams or heavy channel iron for the rafters or will this receiver channel be fine?
Reply:

The black lines are the columns and are 10' apart - square. They are 2-7/8" oilfield pipe concreted in the ground 4'. The red lines are what I am wondering would be the best. They will be welded to the pipe columns on each end and span 10'. All the cross pieces in yellow will be 14 gauge C purlin spanning 10' and welded to the red pieces. No yellow pieces touch the pipe columns.Normal 2x6's will be screwed down on top of the purlins running perpendicular to them. My question is it seems lots of people use receiver channel  https://www.hootensteel.com/searchresults.asp?cat=3469 and just slide their c purlins into it and weld or screw them together. The receiver channel looks flimsy to me like it is significantly weaker than a C purlin. Using the receiver channel to carry the entire weight of all the C purlins seems like asking a lot of them.