Posted by Jim Locker on January 16, 2001 at 07:55:48:
I would not try to raise the house. From what you describe, the room in question is probably an add-on (maybe in a former incarnation it was a porch) and the foundation was not quite adequate to take the weight of the walls and roof.
Study the walls and roof where they join the main structure. Are there any cracks, or signs that they are pulling apart? How about the siding? Is it parallel to the ground, or running downhill?
How far is this back room above the dirt? Can you get access to the floor joists? If so, what kind of shape are the joist ends (where they meet the foundation) in? Rotting perhaps?
You need to answer these questions. Once you do, your choices will be more obvious.
I’ve got a house with a small room on the back for laundry and whatever. It’s about 8x12 with the roof sloping away from the main part of the house. The main part is perfectly level. One of the back corners of this area has sunk it seems about 2-3 inches. The foundation is brick with block in between the brick.
Do you raise the house or raise the floor? Do you shim it or what and where? Whether I do it or not I’d just like to know what’s right before it gets done.
The joists of the house may be separate from the brick veneer. Both would have to be lifted at the same time to avoid pulling the brick away from its attachment to the sheating on the wall that sits on the floor joists. If only the foundation is brick you may be able to take it apart because it is only cosmetic and the foundation actually is pier and beam. If there is a concrete grade beam around the perimeter it is a job for the pros.
Use a hydraulic jack that you can buy at hardware or farm supply stores. They are rated by the tons and are relatively inexpensive. You may need two. Set a jack on block (so it won’t sink) underneath the sill. If you can’t raise it high enough, you may need the other jack so you can alternate between the two when raising it. Jack slowly. Place a block between the foundation and sill once you have raised it where you want it. Do not use wood blocks because of termites/rot. Beware that the whole room has settled and You will probably crack plaster ceilings and walls. Good luck.