Basic Home Repair – raising a sunken floor
Many a home owner can save tons of money by doing the work themselves. All they need is a little guidance in the right areas.
Maybe you have a sagging floor for instance. You might look at the floor as a fixed immovable object but in reality it is generally suspended in the air atop posts and beams.
If you floor is a concrete floor this post can’t help you. This is for suspended wooden floors.
Under the floor is either a crawl space or maybe a basement and you would need to determine where the floor is sunken to be able to find the support member that needs to be repaired. This is pretty easy to do with a level.
Go to the room that has the most noticeable lean in the floor and lay the level on it to see which direction the floor falls. You will need to lay the level all around the room and in different directions to find the lowest point. You may find the lowest point is in a different room or on an outside wall but it is pointing to where the repair needs to take place.
Some reasons for sinking are rotted wooden members that support the floor, the concrete or stone pier has sunken into soft earth possibly from having the soil under the pier being disturbed during excavation and not getting it compacted before placing the pier or there was a shift in the earth below and it cause an area of the house to sink.
These things can all be fixed rather easily.
The main tools and supplies you will need are;
* 25 ton or bigger jacks (you should have two of them. You can get away with 12 ton jacks but it is harder to pump them.) Or house screw jacks.
* Pressure treated lumber for new posts like 4X4 or 4X6 to go under the beam and down to the concrete pier.
* Some 2X4 pieces to nail the posts to the beams when done or metal straps if you like.
* A hammer,
* A sledge hammer,
* 4 two foot pieces of 2X6
* 2 pieces of 1′X1′ 3/4″ plywood for the jacks to stand on.
* A good 4′ or longer level
* clean plastic sheet to lay on under the house
Now it’s time to get to work. You’ll want to be close to the post when you jack up the beam. That way you are only lifting the low end of the beam and not trying to lift the whole beam from the middle.
Generally two beams meet over a post and you will need two jacks to safely lift each beams weight off of the post. Once. To place the jacks properly you first lay down the 2X6 pieces side by side (2 of them) and then you lay the 3/4″ plywood on top of them in the middle then the jack goes on top of that. This gives you a nice big footing to lift from. Make sure the platform you build is level. The jack has to be pointing straight up and down to work safely.
You don’t want a leaning jack with a bunch of house weight sitting on it and it decides to fall over. Work safe and you will have a good time fixing the sunken floor.
Now begin lifting the beam or beams up If two beam ends are being lifted they need to go up at the same rate and height. Now go and check the floor periodically to make sure you are getting it level. You may hear some loud popping and creaking sounds. This is natural so don’t be alarmed.
If you have to lift the floor up more than 1/2 to 1″ you may get some cracks in the walls and they are just cosmetic so they can be patched without too much difficulty. Doors may also not fit their openings if you had to lift a wall with a doorway in it.
When you have the floor level again give it a pump or two more on the jack and cut yourself a new post to fit the new gap from the beam to the concrete pier. You’ll want to place a piece of tar paper on top of the concrete pier and then the new post on top of the tar paper so the wood cannot touch the concrete. This will prevent the wood from rotting due to moisture that wicks up through the concrete. Even though the wood is pressure treated it can and will still rot.
If there are two beams make sure the joint lands in the center of the new post and then lower the beams to the post. After you verify that the floor is still level when you lower the beam back onto the post then take the 2X4 pieces and lay them against the beam sides and down each side of the post and nail them together. You could also use metal plates for gang nailing.
That completes the leveling. You are now experienced in floor leveling.
If you are lifting beams in a basement you would use pole jacks for safety and ease of use. You still want to build the wooden base for the jacks to stand on so you don’t take a chance of cracking the concrete floor.
