Shed Roof Pitch and Rafter Sizing

[MotorSeven]

Thru the rib? The local metal guy here(in business for over 30 years) say's "put a screw on every flat". I have not seen anyone screw thru the rib in a long long time. The big problem with the rib is most installers don't know when to stop, either over torquing, or when nails were used bashing the rib down.

 

[LD1]

Thru the rib? The local metal guy here(in business for over 30 years) say's "put a screw on every flat". I have not seen anyone screw thru the rib in a long long time. The big problem with the rib is most installers don't know when to stop, either over torquing, or when nails were used bashing the rib down.

Around here, its screws through the flats and nails on the ribs:thumbsup:

 

[jcook5003]

I will be using simpson strong ties to attach the rafters to the headers. I suppose I will double them up just to be safe.

I look at my equipment shed frame with 2x8 rafters and 2x8 headers that's 65 years old and wonder about the ways we build these days lol. Working in engineering/design/drafting I understand though.

Thanks for the info guys. Think I should document the build here? Or has it been done enough?

 

[LD1]

Will you be going with an overhang??

If not, I would reccomend using a joist hanger to attach the rafter to the outer header board. you will have to cut the rafters on the appropriate angle. Once them are all attached, at that point, install the inner 2x12 header up tight on the underside of the joists.

If you are using an overhang, use the strong ties on both, but I would still just put ONE header on, then install rafters, and THEN put up the other header. That way you ensure that the rafters are setting SNUGLY on the header.

And if your pole spacing/rafter spacing permits, leave the poles a little longer than the header board. If planned properly, you can attach a rafter to every pole, this will save you a couple of strong ties, and keep the roof more ridgid. It helps keep the rafters from "laying" over since they are only attached to the header board at the bottom, it doesnt take much to lay one over.

 

[BeezFun]

Next question. You guys think with my posts on 12' centers a single 2x12 header is sufficient?

I don't think either of the UBC or IBC codes allow for single headers, the charts are all for double somethings. The issue is a different failure mode. The beam is no longer failing due to bending stress along the strong axis, it's failing in the weak direction because it isn't straight. So it tries to roll over on it's side, making itself get weaker the more it rolls. That's one of the things blocking helps prevent when used on floor joists.

I'd string a line along the edge of the header to keep it straight when you attach the rafters, that will help optimize the strength, and give you a nice straight wall.