Most floor sagging occurs beneath load-bearing walls.
Over time, your home's structural support system can settle, causing the floors to sag and making it difficult to open and close doors. Typically, this occurs in the center of the home where floor joists can settle downward, and while it can happen with any type of foundation, it's more common in homes that sit on crawl spaces than it is in homes with full basements. With house jacks, you can lift the sagging floor joists back to their original height. Does this Spark an idea?
Instructions
Pinpoint the Problem
1. Position a laser level on the floor in the center of a room, facing a corner. Make a mark on the wall where the laser dot appears.
2. Rotate the level, without moving it to the side, and make additional marks in the center of the wall and again in the opposite corner. Repeat this for all the walls in the room.
3. Measure from the floor to each mark on the wall. Where you have a higher mark, the floor beneath is sagging. For example, if the mark on one corner of the room measures 3 1/2 inches from the floor and the opposite corner measures 3 inches from the floor, the floor in the first corner is 1/2 inch lower than the floor in the second corner.
4. Locate the floor joists directly below the lowest spots in the floor. This is usually beneath a load-bearing wall, where the pressure on the floor joists is the heaviest.
Position the House Jacks
5. Place a house jack on a concrete pad directly beneath the sagging joist. If the crawl space has a concrete floor, that is sufficient. Otherwise, you can purchase precast concrete pads, or you can pour a concrete pad in place. Whichever method you choose, the pad should be at least 4-by-4 feet in diameter and 4 inches thick.
6. Raise the house jack, which is a screw-type jack, until the top of the jack is within 2 inches of the floor joist.
7. Position a 6-by-6-inch, 1-inch-thick steel plate between the top of the jack and the floor joist and raise the jack until the plate is snug against the joist. Without the steel plate, the top of the jack would penetrate the joist.
8. Place a 20-ton hydraulic jack next to the house jack and raise the top of the jack just as you did with the house jack. Use another steel plate between the jack and the floor joist. House jacks don't have quite the lift power of a hydraulic jack.
Level the House
9. Raise the hydraulic jack very slowly and go upstairs, or, better yet, have an additional worker upstairs who can continuously check the laser level to determine if the lower section of the floor is rising.
10. Lift the joist no more than 1/4 inch or less, at a time, waiting a few hours or a day between lifting sessions. This reduces the risk of cracked walls.
11. Raise the house jack until the plate is tight against the floor joist. Now, you can lower the hydraulic jack and leave the house jack in place.
12. Repeat the process if you have additional sagging spots in the floor.
Tags: house jack, floor joist, floor joists, hydraulic jack, from floor, jack until, steel plate
