So I am working out a framing plan for an exterior wall made from 2x8s and I want to put a door in it. I plan on using two 2x12s for the header.
The question is, what is the best practice for building the 2×12 header in this deep of a wall?
The width of the header would ideally be 7 1/4" so that the cripple studs above the header are flush with both sides of the header. But that means filling in with 4 1/4" of material, which seems strange.
Do I just make a box out of 2x12s (two the length of the header, plus two at 4 1/4" making the short end of the box)?
Edit: And perhaps would it be best practice to add one 4 1/4" 'header spacer' in the box under each cripple?
Best Answer
since I have no idea why 2x8 framing is being used, i wont bother trying to comment on the design requirements. if its just for insulation, go 2x6 an solid polystyrene foam for insulation. your r -value will be higher than fiberglass in a 2x8 wall.
however, a header that big would be abnormal, not from the height issue, but the depth of the wall. how wide the span is going to dictate the construction. you can do it three ways:
1) (short span) - inside and outside 2x12 on edge, fill with width ripped 2x6 short studs with a ripped 2x6 plate top and bottom between the header members
2) (middle span) - box beam construction. top and bottom plate of 2x8, inside and outside 2x12 on edge. nail together like nails are free. tall assembly, but that's the strongest with minimal material. you can block internally if you want, but it won't make much difference
3) (longest span) multiple 2x12 on edge with plywood filler at center to make with correct
4) (strongest) - LVL instead of spruce. built like 1), but 3 to four times stronger