Strengthen Attic Floor Joists

In my 80 year old house the attic had 2x6 floor joists about 16 oc.

Strengthen attic floor joists. Set a hydraulic jack and post under the beam and jack up the joists about 1 8 in. Jacking them up too fast may cause cracks in the walls and floors overhead. 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. You will have to use a very sturdy piece of wood or some steel plating to reinforce the floor joists.

Squeaks in a floor usually mean that the subfloor has loosened from the joists. They create the structural strength of the attic floor. Pretty sure you mean joists not rafters rafters are the sloped members that run directly under your roof whereas joists are the horizontal members that sit atop the ceiling of the floor below the attic. If your attic joists won t bear the weight necessary to finish out a living space but the engineer cleared them to support floor decking for light storage you can install inch plywood or.

A day until they re level. Tack a beam under the sagging joists. Now it is time to use some wood and screw it into place on the original joist as well as the cross beam. For this fix to work well the upper edges of the joists must be solidly fastened to the subfloor above.

A steel plate can be used the same way. Nailing two 2x4s together will work to span about three joists unless the sag is under a weight bearing wall. Adding a 2 x 4 along the bottom chord of the 2 x 6 ceiling floor joist maybe helpful in stiffening the joist as well. Plywood firmly fastened to the undersides of joists helps prevent this side to side bending and stiffens the floor.

I went to get a permit from the city to finish the attic and they said i needed to reinforce the floor since for a live load it was not strong enough for our span below about 12. You can however strengthen the joists by securing another length of wood to the existing joist called sistering or reduce wobbly floors with block inserts between the joists called. This is a great answer. I recommend three gusset pairs per joist at the quarter points one about every 3 feet.

Where they connect to both the top and bottom joists each gusset pair will transfer approximately 100 pounds that s 50 psf of floor load times the 3 foot gusset spacing times the 16 inch joist spacing divided by the two joists.