How to Raise a Foundation Beam With a Pneumatic Jack

Build a foundation for the jack base by positioning a 6-by-6-inch beam on the basement floor, directly below the foundation beam you'll be raising. Put two other beams perpendicular to the first, one at each end of the beam. Attach the beams together with woodscrews, driven in from above at a 45-degree angle. This arrangement of beams on the basement floor provides the foundation for the jack, spreading the force of the operation across the floor. Without this, the base of the jack might simply indent the concrete floor of the basement as pressure is applied. The beams at each end provide stability to the main beam.

Place metal plates at each end of the beam and put lally columns on each of the plates, extending up to the beam. At a minimum the metal plates should be several inches larger than the base of the column, to spread out the force applied to the column. Turn the threaded bases of the lally columns with a large adjustable wrench until they're tight against the foundation beam.

Put a metal plate in the center of the main 6-by-6 beam. As with the lally columns, the larger the plate the better, but ensure that it's larger than the base of the jack by several inches in each dimension. Position the pneumatic jack on the metal plate. Put another metal plate on top of the jack's piston and place a lally column onto the jack. Raise the jack until it is tight against the beam.

Slowly raise the jack. As the beam raises, adjust the lally columns to either side until they're tight against the beam. Raise the beam in very small increments -- about 1/4 inch at a time.