How can I sand down bumps in a dried self-leveling compound?

compound being scraped on a wall
  • 2-3 hours
  • Intermediate
  • 50-100
What You'll Need
Floor grinder
Sandpaper or electric sander
What You'll Need
Floor grinder
Sandpaper or electric sander

Self leveling compound is used to make an uneven floor more level, before installing new flooring. When dried, leveling compound is very hard, very much like cement. Use leveling compound in areas where the dip in the old flooring or subflooring is 1/4 inch or more. Use a trowel to level the compound as much as possible while it is still wet and pliable. Only use small amounts at a time to prevent quick drying before it is level. A grinder can be used to sand down bumps in dried compound. For smaller bumps, a course sandpaper on an electric sander is effective.

Sand Down Bumps In A Dried Self-Leveling Compound FAQ

Can you sand down self levelling compound?

If self levelling compound dries unevenly, it's no cause for big worry. Uneven self levelling compound can be sanded down.

Use a power sander, as this will be the quickest and most effective method for smoothing out the dried compound. A low grit will work best to make quick work of the job.

Can you add another layer of self-leveling compound?

If your self-leveling compound has settled unevenly or is otherwise disappointing, you can add another layer of compound to create a new and more level finish. However, you need to prime and prep the existing layer or the new layer still will not set and dry properly.

What happens if you add too much water to self-leveling compound?

Self-leveling compound is easy to use, but only if it is mixed and applied correctly. If too much water is added to self-leveling compound, it could end up cracking and even disbonding from the area where it has been placed.

Sometimes, you may also see a white film forming on the surface of the compound, a sure sign that too much water was added to the mixture.

Why does floor leveler bubble?

After placing self-leveling compound that has set and cured, you may see small pinholes or little bubbles. This is known as concrete outgassing and it is a very common problem that occurs with self leveling compounds.

This bubbling effect is caused by several factors. This may occur because of over-mixing the product or even using the wrong tool to mix it with.

You may also see this issue when the flooring under the compound has not been properly primed and prepped for the concrete.

However, these air bubbles can be fixed with a micro-topping material. This thin layer can cover up those little holes and create a smooth, even finish.

How many square feet does a 50 lb bag of self leveler cover?

A little self-leveling compound tends to go a long way. A 50 lb bag of self-leveling compound, if applied at 1/8-inch coverage, will cover 40 square feet of space.