run in shed- few framing questions

[ugabulldog]

I contacted building inspections and I don't need permit, located in GA. This will be a 12' x 34' three sided run in shed for animals. 6x6 pt posts @ 12' OC. 2x4 or 2x6 girts 4' OC for side and back metal panels, single slope roof (no ridge) 2:12 pitch. 2x6 rafters spanning the 12' depth 2' OC with 2x4 purlins for metal roof. My question is what is the best way to attach front and back headers to posts (where rafters sit), single or double 2x10 on top of 6x6 posts, one 2x10 face nailed to front of post, notch post for one or two 2x10, or nail a 2x10 on each side of post (not sure how to bird mouth rafters and it wont sit on both 2x10's. Clear as mud?

[John Raabe]

How are you treating the long (34') side for posts? That will determine the header size.

[ugabulldog]

How are you treating the long (34') side for posts? That will determine the header size.

34' / 3 = 11'-4" OC. I  might go 36' and then 12'.

[Don_P]

One nice way to do them is to rip, in this case a 9.5degree angle along the top edge of the header boards. Set them in notches on both sides of the posts, the inside notch will be lower than the outside one to keep the top angles in plane to support the rafters on both header boards. Keep a consistent gap between notches on top of each post. When you set a rafter across the 2 headers have 2x material ripped to the size of the gap and slide it up through the gap and all the way up alongside the rafter. Nail that filler to the rafter and both header boards... hurricane tie and a good rafter end brace. Y bracing from beam down to posts is usually easier with this gapped header method as well.