Old houses settle, this is simply part of owning an old home. But if you are so inclined to realign the foundation of your home, there are important things to consider long before you crawl under your house. This is a job you definitely do not want to take on yourself and at least one of you should have experience in doing this very dangerous project. I actually made a series of mistakes when I decided to level the foundation of our old home. I will leave it up to the reader which was the worst one.
Car jacks are for cars. One needs no sourcing information regarding this fact. However, it should be clearly stated on the car jack that the weight of a house may exceed the lifting capacity of a car jack. No, I did not attempt to ratchet my house up with a bumper car jack. But never should you use a hydraulic car jack mounted precariously on stacks of wood and blocks to lift the support beams of a house. The overwhelmed hydraulic jack lasted just long enough for me to slide the old concrete foundation pads out of the way before it gave way. The jack was destroyed and the corner of the house buckled cracking the support beam down the center. In an instant, this weekend home repair project became a realty insurance nightmare. The entire support structure of that side of my house would have to be replaced.
After wisely acknowledging the job of replacing the floor support was vastly beyond my carpentry skills, I employed a licensed carpenter to assess the damage. His quote was very expensive. I chalked 10% of his estimate up as negligence on my part. He took a look at the den and bedroom on that corner of the house and had even more bad news for me. The integrity of the walls and even the roof may have been compromised by the collapse. It was apparent by his expression that we both knew I was fortunate to be alive. For the time being, I only had enough funds to repair the support member under the house. I decided I would do the necessary repairs to the walls and roof supports myself.
I will not further embarrass myself by going into detail regarding the walls and roof. In fact, I am an accomplished handyman with considerable skill in home repair/remodeling. However, one should never attempt foundation work on an older home without experienced help. The integrity of my entire house was compromised as a result and now will require more work than the house is worth to repair. The roof now requires patching almost yearly now. The doors frequently require refitting in the jams. The sheet rock and the ceiling in the den and bedrooms have to be repaired and/or replaced yearly now as well. This is not as a result of the foundation, but the overall structural damage done as a result of the collapse.
There are certified contractors qualified to do home foundation work. They have high capacity load jacks designed for the weight. Before they ever go under the house they take precise measurements of the existing support mounts. They also take into account the foundation of the ground the home is built upon. I was somewhat ashamed to see a crew of twelve arrive to level my home when I thought I could do it on my own.