Electrician drilled holes in stair stringer
I had electricians doing work in my basement over the last few days. The needed to run some wiring under the staircase to my basement.
As I was working on something else this morning, I discovered to my dismay that they had drilled holes through the stringers on my staircase to run the wiring.
The holes seem to respect the code requirements here in Ontario for drilling and notching of framing members (i.e., at least 2″ from the edge of the framing member) but the code gives this guidance in reference to joists and I’m not sure whether this would apply to a stair stringer as well.
The stringers are housed stair (rather than notched) and they are 2×10 sawn lumber. Not sure what species. See attached pics.
If it is a problem, any ideas on how it could be repaired? I thought the most straight forward approach might be to reinforce that part of the stair with some angle iron on the bottom of the stringer but I don’t know if that would be sufficient or what the right attachment schedule should be.
Thanks in advance for any advice.
-Patrick
Replies
Not a problem.
The electrical is no problem. If those stringers are not fireblocked, they should be.
How would I do the fireblocking?
The stairs lead from the main floor to the basement so there's just a small area between the concrete basement slab and the stringers. The walls that enclose the sides of the stairwell will be covered with drywall. The back of the stairs that you see in the photos was shot from inside a utility room.
We did not plan on doing drywall inside the utility room (i.e., on the walls or the underside of the stairs) except for the exterior walls to cover our sprayfoam insulation.
Blocking should be at the bottom edge and parallel to the stringer. (There may already be blocking at the top edge. This is OK) The idea is that a fire in the utility room does not have a chimney to creat an updraft to the space above. Using 5/8 type X drywall under the stairs will work as well.
Everything will be OK. I see no problems.
It must be fire blocked.