How To Jack Up A Sagging Floor

The 4 inch lally posts can be replaced by 6 x 6 inch lumber.

How to jack up a sagging floor.

Make sure that the lumber or lally posts are perpendicular when jacking or they may slip out of position. The solution to sagging floors or the damaged sills and joist ends that contribute to them often involves jacking. The jack should be placed directly beneath the center joist. Raise each jack by 1 8 inch at a time this will help to reduce any damage to window frames and plaster or drywall walls above the floor.

Pour self leveling underlayment in the problem area. Secure the jack to both beams top and bottom putting screws into the holes on the flat steel plates that are pressing against the wood. Continue to raise the jack until you feel some resistance. A common scenario is to install temporary jack posts and support beams then permanent posts and beams over new footings.

In this style framing the entire structure will sag in that area usually causing cracks in walls ceilings or doors rubbing their frame you will need a proper footing under the post jack because your lifting much more weight if your correcting a sagging interior floor in ether style framing locate the main support beam in that area the large beam that the floor joist are sitting on raise that area keep in mind if its drastic have the foundation evaluated. If you have access to the basement or crawlspace it is possible to jack up saggy joists until they are level and then sister them so that they remain straight after the jacks are removed. Carefully hoist the jack until the beam reaches the floor underneath. A taut string stretched across the floor will show the amount of deflection and improvement.

Foundation repairs are the most expensive reason for sagging floors in old houses. You ll need to hire a structural engineer or foundation specialist to jack up and level the house and then shore up your home with pilings beams or even put new footers on the foundation. Stand your floor jack between the two beams on top of the one that s on the floor and turn the thread on the jack until it wedges under the top beam.