How To Jack Up Floor Joists

Lower the hydraulic jack to transfer the floor load to the new screw jack.

How to jack up floor joists.

Tiger brand adjustable floor jack model js 15 15 gauge floor jacks telescoping jack for temporary support size range 1 1 3 4 4 out of 5 stars 368 19 67 19. The steel plates should be a minimum of 25 inch 0 6 cm thickness and large enough to distribute the full load of that jack across the beam. The sagging floor was the symptom and somewhere under the house there had to be a cause. Stretch a string across the floor to evaluate the amount of deflection then use it as a benchmark for improvement when jacking.

The only tools required is a bottle jack string straight claw hammer circular saw and a light source. On both sides of the problem area. Drive 16 penny nails through the holes in the plates and into the wood framing. Jacking them up too fast may cause cracks in the walls and floors overhead.

Set a hydraulic jack and post under the beam and jack up the joists about 1 8 in. Wooden shims are often used to work out squeaks and stabilize spongy areas but they can also be used for slight adjustments to specific places. If the correction is minor only a 1 4 inch over an 8 foot span using shims between the floor joist and the subflooring can often rectify it without the need to raise the floor joist with a jack. Make repairs to settling piers and weak joists to fix swagging floors and roof lines.

A day until they re level. Adjust the screw jack up or down to achieve a level surface. Well after doing the navy seal crawl up under the house we found that the joists that were supporting that floor were not actually attached to the sill plate any longer as seen in the photograph below. Adjust the screw jack so that the top and bottom plates are flush to the wood surfaces above and below.

Where these repairs are not sufficient also consider shoring up joists or beams that were cut drilled or notched for pipes wires or ducts.