Self-leveling compound is generally used as an easy way to smooth out the rough surface of concrete or gypsum. If you have a different type of floor or under-floor heating coils, make sure the compound is compatible. Self-leveling compound allows an unobstructed installation for tile, carpet, vinyl and even hardwood. It is not intended to fill in or lengthen the floor. There a several basic self-leveling compounds available; water-based self-leveling compound is the most common.
Step 1 - Consider Where to Use
You should not attempt to use self-leveling compound for leveling a floor that has a slope due to settling. Raising a one inch or more slope with self-leveling compound will cause problems. Some of these problems may include a tripping hazard or issues with opening and closing closet doors in the area. The purpose of the compound is to smooth a surface and raise minor flaws where needed. The rise should be no more than five millimeters.
Step 2 - Understand Consistency
It can be a bit challenging to get the right consistency with self leveling compound. The most common terms to describe the correct consistency of the mixture range from “pea soup” to “a thin milkshake”. Depending upon whether you are a vegetarian or a dessert lover, these descriptions can give you an accurate visual.
Step 3 - Mix
Read the manufacturer’s instructions and follow their recommendations for mixing. In most cases you will measure the correct amount of clear water, approximately 1 1/4 gallons. Then add the corresponding amount of powder, approximately half the bag. You should make only the amount of compound you can use in approximately 20 minutes. Add the powder slowly while stirring. The most precise way to stir the mixture is to use a drill with a paddle attachment. You can control the speed more accurately than mixing by hand. Mix for at least two minutes, scraping the sides and bottom with a paint stir stick if necessary. If the consistency reminds you of cookie dough you will need to add water to thin it. You are looking for a thick liquid you can easily pour without it running.
Step 4 - Apply
Locate the lowest point of the floor. You will start here allowing the mixture to puddle. If there are several lower points on the floor, pour an amount equal to a puddle on each point. Once the puddle area is no longer moving, feather that area using a flat trowel.
Pour only an amount equal to the length of your reach. You will need to spread the mixture after you pour it. If it moves too quickly the consistency is too thin. If it does not move at all, the consistency is too thick. In most cases the error is to make the consistency too thin. Do not use mixture that has been sitting more than 20 minutes in the bucket.
Step 5 - Apply a Second Coat
Drying time is generally two hours depending on the heat and humidity. The manufacturer will give you a recommended drying time between coats. Use the same consistency for any follow up coats of self-leveling compound.