How To Level Old Floor Joists

A day until they re level.

How to level old floor joists.

Generally this is caused by a bowing of the floor joists which very often are not strong enough to fully support the weight placed on them. If the floor slants irregularly cut strips that bridge the cap at each floor joist. Set a hydraulic jack and post under the beam and jack up the joists about 1 8 in. A plywood subfloor will bridge any minor waves in the existing floor and leveling compound would help too.

A common scenario is to install temporary jack posts and support beams then permanent posts and beams over new footings. You will have to make sure your joists can handle the addition of considerably more weight from the plywood subfloor and any floor coverings. Floors in older properties are very often out of level. Jacking them up too fast may cause cracks in the walls and floors overhead.

If the uneven floor is due to floor joists that have warped or twisted over time or were incorrectly installed the only way to level the floor is to remove the subflooring and shim the joists. If you have an uneven floor you may need to think about leveling floor joists with shims. Tack a beam under the sagging joists. Nailing two 2x4s together will work to span about three joists unless the sag is under a weight bearing wall.

Screw the strips into the floor joists or subfloor. Use screws to secure the leveling strips to the floor every 16 inches. Leveling the floor with shims is when you attach thin wedge shaped pieces of wood on top of the low areas of the joists to make the top joists even. On the top side of the floor another fix it idea to lay down new hardwood over the existing floor.

This job can run you 1 000 and 5 000 depending on the extent of the job. The solution to sagging floors or the damaged sills and joist ends that contribute to them often involves jacking.