I have a double wall chimney (not currently in use, but I am trying to get it there) sitting ~1" from a roof joist on the right side and basically touching a manufactured joist in the floor below on the left side (see the first picture below). I need to move the chimney ~2 inches to the right to have proper spacing from the floor joist, and it looks like the only simple way to do that is to cut the roof joist on the right and install a header.
NYS building code has this to say about roof openings:
I am planning to do a double header (hung with joist hangers for it and the tail joist above) that will be ~3.5' from the joist bearing, so as far as I understand I need to double the trimmer "of sufficient cross section to support the rafter framing into the header". Does that mean I need to double the full 18' length? Or as one person I asked said, only to 2' past the header?
The main reason I am hesitant (besides finding 20' 2x10's) is that there is a floor/ceiling framed ~2/3's of the way up (not connected to the joists, see the second picture) and the only way I can think to fit a full length board in would be to try and open the soffit and insert it from outside.
At the bottom it will just be the birds mouth and below left, so I am going to put angle brackets on each side to tie the stub into the bottom plate.
I am trying to get this done this week because I have people coming Thursday (9/23) to spray foam the roof deck and walls, and I would rather not have to have them skip this part and do it later myself.
Thanks for reading!
Chimney as it goes through the roof (I also need to replace the chimney flashing and cut the furring strips back to have proper clearance)
The space showing the floor above and the full rafter span. The chimney is in the right corner, you can kinda see it just above the trash can.
NYS building code has this to say about roof openings:
The roof is framed with 2x10's (that have been trimmed down to 9" for some reason) with ~18.5' rafters at a 12/12 pitch.
I am planning to do a double header (hung with joist hangers for it and the tail joist above) that will be ~3.5' from the joist bearing, so as far as I understand I need to double the trimmer "of sufficient cross section to support the rafter framing into the header". Does that mean I need to double the full 18' length? Or as one person I asked said, only to 2' past the header?
The main reason I am hesitant (besides finding 20' 2x10's) is that there is a floor/ceiling framed ~2/3's of the way up (not connected to the joists, see the second picture) and the only way I can think to fit a full length board in would be to try and open the soffit and insert it from outside.
At the bottom it will just be the birds mouth and below left, so I am going to put angle brackets on each side to tie the stub into the bottom plate.
I am trying to get this done this week because I have people coming Thursday (9/23) to spray foam the roof deck and walls, and I would rather not have to have them skip this part and do it later myself.
Thanks for reading!
Chimney as it goes through the roof (I also need to replace the chimney flashing and cut the furring strips back to have proper clearance)
The space showing the floor above and the full rafter span. The chimney is in the right corner, you can kinda see it just above the trash can.
