Strengthen Floor Joists From Above

Set a hydraulic jack and post under the beam and jack up the joists about 1 8 in.

Strengthen floor joists from above. The nice thing about a beam and. As incremental parts of a building s structure joists are not easily replaced. Strengthening attic joists for live loads by sistering if the attic joists are not adequate one way to strengthen the floor for live loads is to sister the old joists. Lay the new sheets perpendicular to the floor joists and orient panel ends over joists.

Choose ring shank nails or screws that are long enough to penetrate the joists by 11 2 in and space them every 6 in. Tack a beam under the sagging joists. Sistering is the process of adding a new joist next to each existing joist. 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.

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. Nailing two 2x4s together will work to span about three joists unless the sag is under a weight bearing wall. Add an additional row of fas teners midway between the joists to pull the layers tightly together.