As a foundation specialist we often get requests for floor support posts or screw jack replacement do to deteriation from rust. We have found that a majority of houses built in the 70’s in the Bay Area have metal screw jacks originally installed for the interior floor support. The screw jacks installed at this time were usually not done properly because they were not elevated on pier blogs, but instead were installed at grade with no additional moisture protection. This leads to premature failure in the screw jacks because they rust out at the base over time. This leads to uneven floors, squeeks in the floor, and doors sticking.
To fix this we come in and remove the existing deteriated jacks and replace them with new galvenized screw jacks. While doing this we raise the existing pier blocks a minimum of 6″ above grade using a high strength rapid set grout. Once all screw jacks have been replaced then the floors can be releveled.