The nice thing about a beam and.
Strengthen floor joists from above.
Choose ring shank nails or screws that are long enough to penetrate the joists by 11 2 in and space them every 6 in.
Add an additional row of fas teners midway between the joists to pull the layers tightly together.
Nailing two 2x4s together will work to span about three joists unless the sag is under a weight bearing wall.
The joists are quite small 5 5 inch x 2 5inch with tiles above so i would also to take this opportunity to strengthen the floor as i think we re borderline on the deflection front and i dont fancy doing the floor again.
As incremental parts of a building s structure joists are not easily replaced.
Set a hydraulic jack and post under the beam and jack up the joists about 1 8 in.
To keep the walls above from cracking and to prevent other damage the joist sag is lifted a tiny bit at a time usually no more than 1 4 inch every few weeks.
Jacking them up too fast may cause cracks in the walls and floors overhead.
Sistering is the process of adding a new joist next to each existing joist.
A day until they re level.
You can however strengthen the joists by securing another length of wood to the existing joist called sistering.