Strengthen Floor Joists From Above
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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.
Strengthen floor joists from above. You can however strengthen the joists by securing another length of wood to the existing joist called sistering. As incremental parts of a building s structure joists are not easily replaced. Lay the new sheets perpendicular to the floor joists and orient panel ends over joists. 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. 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. The nice thing about a beam and. Tack a beam under the sagging joists.
A day until they re level. Set a hydraulic jack and post under the beam and jack up the joists about 1 8 in. Choose ring shank nails or screws that are long enough to penetrate the joists by 11 2 in and space them every 6 in.