Joists Sistering Garage Door

Reinstall the blocking on both sides of the joist.

Joists sistering garage door.

The problem with sistering a garage door header is that you commonly cannot effectively put replacement pieces on both faces of it and bolt through assuming it is cracked not rotted so it the bad one be left in place. A day until they re level. Attach a bar clamp or deck devil to the bottom of the joist and to the top of the 4 4. Best practice would be to jack each floor joist to remove the dead load deflection install the new sister and then remove the jack.

If you don t do this the new joist won t carry any of the existing load. That way the new and old joists share in carry the dead load. Pull up on the joist until the top of the joist is flush with the bottom of the 4 4. Nailing two 2x4s together will work to span about three joists unless the sag is under a weight bearing wall.

Lay a four foot 4 4 across the top of the sagging joist and two adjacent joists. Although you can construct a garage using thicker stronger joists 2 inch by 6 inch joists are sufficient for most garages even if you intend to build an attic storage area above your garage. Set a hydraulic jack and post under the beam and jack up the joists about 1 8 in. Fine homebuilding notes that 2 inch by 6 inch garage joists will support a weight of up to 50 pounds per square foot.