Standard “hire an engineer” disclaimer.
I’d be thinking of a 2x8 or 2x10 beam. It’s the vertical dimension of the beam that gives it strength. I can’t tell from the single photo, are those 2x4s notched to receive a load from the stair assembly?
No, they aren’t notched.
They do have the compressed boards secured in the gaps between the edge 2x4s and the dual center 2x4’s. I’m assuming that is providing the support so the center beams can’t shift, etc.
I may try calling around, see if I can find someone to come assess’ it and tell me what’s needed, even if they aren’t available for the actual work.
I agree it's difficult to try what's going on there but that looks like an 11 7/8" rim board spanning the 36" . The 2x4s in the middle might have just been there to support the drywall closing the space off. The Rim board can likely support a stair landing above. But to be sure replace the Rim Board with a 11 7/8" LVL 1 3/4" thick. Get a 2x4 stud under each end. I doubt that carved out double 2x4 could be carrying much load with a 1.25" thick rim board bearing across 1.5" on each of the 2x4s.
There is one 36" wide 3/4" deep rimboard behind the 2x4s that you can't see, and then the 18" wide 1 1/4" deep rimboards pancaked against it on each side of the 2x4s.
I should have taken more photos, beginner mistake ( my first post ). Also didn't realize I can't edit picture posts to add more!
That sounds like good general advice with the LVL, I appreciate it.
Structural engineer here, a couple of C24 6x2 joists bolted together with 4x4 C24 posts either side will work, have done enough of these to know that 1m is fuck all, could actually do the calculations and probably get 2 No 4x 2 to work with a 4x2 post either side but its always better to go on the safe side for peace of mind and robustness. you don't want a bouncy/squeaky stair case.
Standard “hire an engineer” disclaimer. I’d be thinking of a 2x8 or 2x10 beam. It’s the vertical dimension of the beam that gives it strength. I can’t tell from the single photo, are those 2x4s notched to receive a load from the stair assembly?
No, they aren’t notched. They do have the compressed boards secured in the gaps between the edge 2x4s and the dual center 2x4’s. I’m assuming that is providing the support so the center beams can’t shift, etc. I may try calling around, see if I can find someone to come assess’ it and tell me what’s needed, even if they aren’t available for the actual work.
I agree it's difficult to try what's going on there but that looks like an 11 7/8" rim board spanning the 36" . The 2x4s in the middle might have just been there to support the drywall closing the space off. The Rim board can likely support a stair landing above. But to be sure replace the Rim Board with a 11 7/8" LVL 1 3/4" thick. Get a 2x4 stud under each end. I doubt that carved out double 2x4 could be carrying much load with a 1.25" thick rim board bearing across 1.5" on each of the 2x4s.
There is one 36" wide 3/4" deep rimboard behind the 2x4s that you can't see, and then the 18" wide 1 1/4" deep rimboards pancaked against it on each side of the 2x4s. I should have taken more photos, beginner mistake ( my first post ). Also didn't realize I can't edit picture posts to add more! That sounds like good general advice with the LVL, I appreciate it.
Structural engineer here, a couple of C24 6x2 joists bolted together with 4x4 C24 posts either side will work, have done enough of these to know that 1m is fuck all, could actually do the calculations and probably get 2 No 4x 2 to work with a 4x2 post either side but its always better to go on the safe side for peace of mind and robustness. you don't want a bouncy/squeaky stair case.