Leveling a Droopy Floor
Break out a section of the basement floor and create a 24x24x8inch concrete pad for the jack to sit on.Let concrete sit of at least a week. Put jack on concrete. Insert a 4x4 pressure-treated beam long enough to cross several joists.Raise jack until beam is snug against joist, and rise jack Â¼ turn again. Wait a week and rise another quarter turn.Repeat process until droop is gone.