Floor levelling refers to the process of making a floor perfectly even and removing all flaws. This is common when laying wood flooring over concrete. Homeowners can use cement board and other level materials for their subfloors, but if they want to put flooring down on concrete slabs, the slabs must be treated first. Even small rises or depressions can eventually warp and ruin the floor. There are several steps to levelling a concrete floor properly.
Cleaning the floor is a vital step for most flooring projects. Not only will cleaning remove accumulated grime and make flaws in the floor easier to spot, it will also give flooring adhesives and additional compounds a reliable surface to bond with. The grime and oil on a concrete floor will cause the bonding to fail. Once the floor is clean, you can use a straightedge or string to look for bumps or depressions.
Grinding is the process of wearing down bumps and ridges on the concrete floor. You probably do not have anything in your house that can effectively grind concrete floors--the best tool is a large push grinder that you can wheel across the floor. You can rent them at construction stores. If you have only a few bumps to tackle, you can try using a hand-held version. Make sure you clean up all dust caused by grinding before moving on.
Resurfacing is a complete method of levelling that strips away the top layer of the concrete and replaces it with a fresh layer. This is the most expensive option for levelling, but you may want to consider it if your floors have significant cracks and damage as well as level problems. You will need to use a concrete adhesive between the old foundation and new layer.
Levelling compounds are epoxies and other synthetic chemicals that you can use to create a level surface. You mix these compounds together and pour them out in liquid form onto your floor. Some are pastes that you can rub into flaws to smooth them out, while others are self-levelling and naturally spread to form a level surface.