I'm cutting a new rough opening in my floor for a spiral staircase. Please corroborate my findings if you can:
shall be framed with a header and trimmer joists. When the header joist span does not exceed 4 feet, the header joist may be a single member the same size as the floor joist. Single trimmer joists may be used to carry a single header joist that is located within 3 feet of the trimmer joist bearing. When the header joist span exceeds 4 feet, the trimmer joists and the header joist shall be doubled and of sufficient cross section to support the floor joists framing into the header. Approved hangers shall be used for the header joist to trimmer joist connections when the header joist span exceeds 6 feet. Tail joists over 12 feet long shall be supported at the header by framing anchors or on ledger strips not less than 2 inches by 2 inches.
I don't understand the portion highlighted in red. Wouldn't the cross section of the header be simply 1.5" x joist depth? I'll be using 2x8s to match the joist depth.
I'm going to build two temporary walls while I frame this box. I imagine leaving those walls in places would enhance the rigidity of the floor joists supported by the new header. I wouldn't have to worry about reinforcing the slab because the header is transferring the load to other joists, correct?
- A 61" staircase is about the minimum width necessary to achieve the 26" code minimum distance between the railing and the center pole
- The opening for this staircase should be about 4" larger than the staircase size, i.e., about 65" inches
- I will need to remove 4 joists at 16" on center to make a 65" opening (if I remove only three, I believe I would have only 1/8" clearance in some places after I drywall the rough opening)
- The rough opening requires double headers and double trimmers since the header span is greater than 4 feet
- I'll need to use joist hangers, since I'll be spanning 78.5" when I chop four floor joists
shall be framed with a header and trimmer joists. When the header joist span does not exceed 4 feet, the header joist may be a single member the same size as the floor joist. Single trimmer joists may be used to carry a single header joist that is located within 3 feet of the trimmer joist bearing. When the header joist span exceeds 4 feet, the trimmer joists and the header joist shall be doubled and of sufficient cross section to support the floor joists framing into the header. Approved hangers shall be used for the header joist to trimmer joist connections when the header joist span exceeds 6 feet. Tail joists over 12 feet long shall be supported at the header by framing anchors or on ledger strips not less than 2 inches by 2 inches.
I don't understand the portion highlighted in red. Wouldn't the cross section of the header be simply 1.5" x joist depth? I'll be using 2x8s to match the joist depth.
I'm going to build two temporary walls while I frame this box. I imagine leaving those walls in places would enhance the rigidity of the floor joists supported by the new header. I wouldn't have to worry about reinforcing the slab because the header is transferring the load to other joists, correct?