I am presently renovating a house that has a 4" difference from the middle to the one side due to the subsidence.
It is a semi-detached duplex, with 3 floors including the basement. The worst is the basement and the 1st floor (4" difference). Now the foundation is no longer subsiding because some stakes are driven to the ground. Now I am going to level the floors and ceilings.
I was told the proper approach was to first remove the floor and subfloor, then find the highest joist and draw a level line around the wall at this point. A this point I would have two options:
- Drill holes little bigger than the bolts and sister new joists with old ones with bolts and nuts.
or
- Use construction adhesive to glue the new joists to the old ones.
I have no idea which one is better or maybe neither of them works. I'd like y'all's input. Thanks!
Best Answer
Sistering is a common approach to this situation. However, if it's a multiple-floor building, you should have an engineer involved to make sure that the footings in the basement are now sufficient and that the repairs will properly carry the weight of all the floors. You will also need to figure out how to deal with the internal walls on each of the floors.
To answer your specific question, gluing the joists together and holding them together with bolts is the common approach.