Ok To Use 2 X 4 For For Roof Rafters

It is always better to have a large rafter rather than be concerned with a sagging roof.

Ok to use 2 x 4 for for roof rafters.

Less expensive 1 3rd less board footage of lumber fewer pieces to handle fewer joist hangers to have to attach and only one half as many screws to attach the roof steel. You can frame a whole house with nothing but 2x4 but it s easier to do a shed as you won t need engineering probably. The back of the roof will attach to house with 16 2x4 and lag screws. Front and sides will sit on deck on a 2x4 wall with studs 24 oc and screened in.

I think you will be fine with 2x4s so long as they are closer than 48 apart. Rather than having 2 4 purlins every 12 it would make far more sense economically to use 2 6 purlins every 24. If you live in an area that requires a shed roof rafter to support a heavy load then an spf rafter can only span 7. Also if you want to make things cheaper you can do a single slope of the roof and basically cut out the eve cost.

As mentioned above a 2 4 spf shed roof rafter can span 11. You can use them for roof floor and even wall framing but few sheds will need trusses for walls. Rafters to 2x4 with joist hangers. Makes construction easier too.

An syp rafter can span 11. Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes. The secret word is truss. At the pitch range you are looking at the 2x4 is just fine up to 8 6 depending on the lumber grade.