What Is Self-leveling Compound?

A man uses self-leveling compound.
  • 2-3 hours
  • Intermediate
  • $20-80
What You'll Need
Safety glasses
Face mask
Self-leveling compound

A self-leveling compound is a chemical mixture used to smooth uneven concrete or wooden floors. It is ideal for filling dips in wooden floors or for smoothing concrete ones. It is very important to have an even-surfaced floor when planning to place ceramic tiles or any other floorings because uneven surfaces cause tiles to crack.

Preparing the Floor

The floor should be stable before applying a self-leveling compound. With concrete floors, this is hardly an issue, but with wooden subfloors, the task may be almost impossible to handle. If a wooden subfloor moves when you step on it, a self-level compound might not be the best decision: it will break. Furthermore, the floor needs to be cleaned from dust and dirt before applying a self-leveling compound.

Applying Primer to the Floor

Before placing the self-leveling compound, it is essential to apply a brush or two of primer. This way, you will ensure a solid bond for the self-leveling compound. You have to wait until the primer dries because if wet, it may react with the self-leveling compound and make it less stable. As part of the process, air the room after applying the primer and you will speed up drying and eliminate unpleasant smells.

Identifying Uneven Surfaces

You can slide a framing square over the floor and find if it has any cavities. Mark these spots: they will be the ones you apply self-leveling compound to.

Prepare to Work with a Self-leveling Compound

It is important to work fast because the self-leveling compound dries very fast. The whole process of pouring, mixing, and spreading the compound should take no more than 20 minutes. The manufacturer’s guide should be followed. It is recommended to work with gloves and a face mask to avoid breathing the dust from the self-leveling compound: it may lead to cough or even allergies. For best results, you should mix the compound with a drill and add as much water as specified in the instructions. It is better to use cold water, thus lengthening the period before the compound dries up.

Applying a Self-leveling Compound

Immediately after mixing the compound, you need to spread it to the previously identified uneven areas. Wait a little while until it begins to thicken and then use a drywall tool to make it even. Then you can spread it out to the whole room and ensure that the floor is even. It is important to know what you are doing and to do it quick. When the compound begins to thicken, you shouldn’t try to slow down the process by heating it up or by adding additional water. It will spoil the self-leveling compound and make it break afterward. In four hours, the compound will be hard enough to step on it.

Cleaning Up Afterward

Have a container on hand to store any leftover self-leveling compound, especially if you're filling up cavities. Wash the tools and containers you use with water right after using them to remove as much compound as possible. You may not be able to remove all the compound, in which case those tools will become the ones you use every time you work with self-leveling compound.