Dealing with uneven floors is a part of the trade when installing flooring. Before you can do a good job of installing wood, laminate, or any other flooring, you need a good subfloor to start out with. Here are some things to consider when your subfloor is uneven.
1. Self-leveling Compound
When you are dealing with uneven floors, one option that you have is to use self-leveling compound. This compound can potentially be utilized on a concrete slab or a wood subfloor, and it works well when you are dealing with dips in the floor. Self-leveling compound is similar to concrete, typically coming in large bags in powder form. You mix it with water in a bucket until it creates a thick paste. You can then spread it out on the floor in the affected areas. It will find the lowest areas of the floor and work to level out the subfloor.
With this type of substance, you can apply it with a trowel and spread it evenly over the floor. Then you will need to let it dry before you do anything else with the floor. If you have a large height difference in the floor, you may need to apply multiple layers of the self-leveling compound. In this fashion, you can create a ramp effect if needed.
Another option that you could utilize is installing plywood on top of the old subfloor. By putting in new plywood, you can effectively create a new, perfectly smooth surface to install your flooring on. This method is easiest if you are dealing with a wood subfloor, but it can be done on top of concrete if need be.
If you have a large difference from one area of the floor to the other, you could find the appropriate thickness of plywood and install it over the top of the lower portion of the floor. This will allow the two areas of the floor to meet up at the same height.
If you are dealing with a wavy floor, you can just put plywood over the top of the entire area. Since plywood sheets are usually 4x8 feet, they should be big enough to span any differences in flooring height and provide you with a sturdy subfloor to work with.
When installing the plywood, make sure that you use nails that are thick enough to go through the plywood and all the way down through the floor below. If you are installing on top of concrete, you will have to use bolts that can go through the concrete surface.
Another option that you may have is to grind down the floor. This works best if you have a large hump in the middle of a concrete slab. If you have a hump in a wood subfloor, you can sand it down with a sander.