How to Raise Flooring

Raising your floors might be necessary for a number of reasons, including to increase head clearance in a bottom level floor, fix sagging floors, to get your floor off of a dirt foundation and away from potential exposure to moisture, or simply to make a room feel more intimate. Raising your flooring is a slow process that can take several weeks if you want to avoid damaging your floors or plaster walls.

4-by-6-foot beam
Rafter ties
Drill
2-inch screws
2 3/4-inch thick steel plates
2 4-by-6-foot posts
2 20-ton hydraulic jacks
2 lally columns

Instructions

- 1
  Get into the area under the flooring that you want to raise. To access the flooring itself, enter basement crawl space, or remove the ceiling panels or the entire ceiling that covers the flooring above it.
- 2
  Attach a 4-by-6-foot support beam that spans underneath the floor joists in the middle of the floor you want to raise. The support beam should run perpendicular to the floor joists. Attach rafter ties with a drill and 2-inch screws. Rafter ties are small metal items that you drill screws in to attach a support beam to a rafter temporarily to add additional support.
- 3
  Screw two 3/4-inch-thick steel plates under two floor joists spaced six feet away from each other, if you have a 8-foot-wide room.
- 4
  Place two 4-by-6-foot posts directly underneath the support beam you installed under the floor joist. Place two 20-ton hydraulic jacks on top of the posts under the steel plates. Raising the flooring with two jacks will help distribute the weight evenly and avoid damage to your floors.
- 5
  Place a lally column with a threaded adjustable base on top of each jack. The size of the lally column depends on the distance between the posts and the support beam.
- 6
  Raise each jack by 1/8 inch per day. Continue to raise the jack until the floors reach the desired height. This process might take two to three weeks.

Siliceous Vs. Carbonate Concrete

How to Raise a Full Basement

Floors