How thick can you pour self levelling compound?

You can pour self-levelling compound at a thickness of anywhere between a feathered edge 0mm- up to around 50mm. Every product is different so you will need to find the manufacturer’s product datasheet, or read the side of the bag.

Most self-levelling compounds are ONLY designed to be applied in a thin 3mm-15mm layer, as their main job is to just cover the entire surface, smoothing and removing any imperfections in the sub-floor.

Note: Your floor rarely needs to actually be “spirit level”, but it does need to be smooth and continuous with no discrepancies.

If you truly need your floor to be “level” and it is a long way out, you need to be looking at products that can be applied up to 50mm in depth. Even when using these products it may still recommend you apply them in layers. Once you start getting deeper than this you are getting dangerously close to floor screeding and concreting territory.

What is self levelling compound?

Self-levelling compound is also known as a floor screed or floor levelling mix. It is a thin layer of a cement-based mixture that is applied to subfloors in order to level out any bumps.

It is called a self-levelling compound as it, in theory, self-levels. What this means is that you don’t have to worry about getting the mix perfectly level. It should flow across the floor, and correct any errors.

While this does generally work, there are limits. It doesn’t flow like water so will not perfectly level over a large area and may require a bit of help from you.

You use a self-levelling compound to turn a bumpy, un-even subfloor into a perfectly smooth surface. This is great when you are fitting a solid floor such as tile or wood.