If a stroll across your living room floor feels like crossing the deck of a ship on the high seas, it's time for leveling. Out-of-level floors are not only a nuisance but sometimes a safety hazard as well.
Such floors will likely result in cracks over windows and doors, or doors and windows that stick and are difficult to operate.
Unfortunately, most homes have floors that are out of level. Some of the causes are poorly compacted soil, excessively damp soil, excessively dry soil and shrinking support posts under the floor.
Homes constructed on a hillside, on expansive soil or in earthquake country will probably require the services of a licensed soils engineer and structural engineer, although some of the following remedies may apply.
If you've visited the crawl space below your home, you're familiar with the foundation at its perimeter and the various piers scattered about the interior. Atop these piers, which vary in depth from home to home, are support posts called underpinning. These support posts are attached to a wood block embedded into the concrete pier at the bottom, and at the top to floor support beams called girders.
Over time these piers may either sink or rise depending upon the soil in which they are embedded and its moisture content. If there is irrigation on one side of the home along the foundation resulting in water getting under the home, the piers likely will be pushed up causing the floor to rise. Or soil at the side of the home could be extremely dry due a drought condition, causing a sunken pier. In either case there is something you can do.
Start your floor-leveling project with a six-foot level and a Sherlock Holmes mentality. Walk the floors of your home and identify the general areas that appear out of level. Place the level over the floor in various directions and locations. Doing this will reveal where the high and low spots are.
Working under the house can be dirty and dark so wear coveralls, carry a drop light and all the tools you'll need. It helps to have an assistant up top.
Also you'll need a few feet of replacement post material, a couple of lengths of 2 by 6, a handful of 16-penny nails, a circular saw, a hydraulic jack and lots of patience.
At the locations where the floor is high, place the floor jack over a block of wood directly under the support beam and a couple of feet from the pier. Using a short piece of post material, jack the floor up slightly, just enough to relieve any pressure on the existing support post, and knock out the existing post. Cut a new support post shorter than the one removed by the amount calculated with your level from above and place it between the pier and the support beam. Slowly lower the jack until the support rests firmly on the new support post and toe-nail the new support post to the pier and the support beam with two 16-penny nails at opposite sides. That's four nails at the top and four nails at the bottom. You can also use the approved metal connectors at both locations for a more positive connection.
At the locations where the floor is low, the process is the same with one exception. The new support posts being installed will need to be cut longer by the amount calculated with your level from above.
In severe cases where the condition has existed for a long time, a deep saw cut may be required at the underside of the support beam, in one or more locations, to make the timber yield to accommodate vertical movement of the floor. Short pieces of 2 by 6 should be nailed onto either side of the support beam in those locations to offer additional strength.
If you live in an area where the soil is expansive and is subject to regular movement, there is an alternative to the conventional wood support post.
An adjustable floor jack or "screw jack" is a metal device that is useful when there is frequent movement because adjustments can be made with little effort and without getting into all of the work outlined above.
Don't be surprised if a few of your doors and windows that were previously sticking operate well after your floor-leveling project.
