How to use self levelling compound

If you’re just learning how to use a self levelling compound, we recommend hiring a professional to do it for you. As you’re working with polymer-modified cement with a high flow capacity, it’s not something you should try pouring yourself unless you’re 100% confident in your DIY skills.

However, if you’re still keen to get started, then we’ve put together this step-by-step guide to make things as easy as possible for you.

How to lay self levelling compound

Levelling compound works on all types of substrates, including screed, concrete and even existing tiles and timber. It’s great for uneven floors. However, there are various preparation methods required to make sure the end result is smooth and flat.

Firstly, you’ll need to check how uneven the floor actually is, because if the discrepancy is more than 5mm, a floor levelling compound isn’t the best option.

Thankfully, there’s an easy way to check. Using some marbles or other smooth balls, drop them in various places along your floor to find out where it dips the most. Then, take a 6ft spirit measure and place the edge in the dip. Lift the other side until the bubble is in the middle of the spirit measure and then use a ruler to work out the resulting gap. If it’s more than 5mm, you’ll need to find an alternative way to level your floor.

Tools you’ll need for the job

• Scraper
• Filler
• Duct tape
• Primer
• Self levelling compound
• Mixing paddle
• Large bucket
• Steel trowel
• Spiked roller
• A sturdy drill

How to use a self levelling compound

Prepare the substrate

Once you’re sure you can use a self levelling compound, your next step is to prepare the substrate (base) of your floors. Use a scraper and a hard-wired brush to remove any dirt and debris, then sweep and vacuum.

To prime your floor, you’ll need to clean it and remove contaminants such as floor paint, adhesives, laitance etc. This stops the compound from bonding to them instead of your substrate. If your floor is silky smooth, you’ll need to roughen it slightly to ensure a stronger compound bond.

Once this is complete, add a floor primer and leave it to dry overnight.

Mix the compound

Take your bucket and follow the instructions on the self levelling compound you chose. It will usually include adding a mix of cold water first and slowly introducing the compound using a mixing paddle or electric mixer until it’s lump-free and at the right consistency.

Top tip: Go easy with the water as you pour (unless you want to wait for ages for your compound to dry!)

Pour the mixture

Once the compound is ready, pour it onto the floor from the farthermost part of the room and work backwards. Use your steel trowel and work the compound in sections, following up with a spiked roller to make sure there aren’t any air bubbles. Continue until the entire floor is covered, smoothed, and rollered.

Leave to dry

Make sure the room is well ventilated and around 20 degrees celsius. Strong sunlight or cold drafts can unevenly dry your compound and cause problems such as cracking or crazing. This is why, if you have underfloor heating, you need to make sure you use a latex polymer.

How long does a self levelling compound take to dry?

Depending on the compound used, drying takes between one hour and six hours. However, we always suggest leaving it overnight to settle before walking on it.

How does self levelling cement work?

Self levelling compounds are spread in thin layers to level floors, using gravity to even it out. They allow concrete flexibility so they can move without cracking.

How to use self levelling compound over tiles

If you want to pour self levelling compound over tiles, you need to thoroughly clean and abrade the area first. Then, follow the same steps above to achieve the desired results.

How much self levelling cement do I need?

The amount you need depends entirely on the square footage of the room you want to even out. For example, a 20lb bag of self levelling compound will cover around 20 square feet at around ⅛ inch thick.

How to mix self levelling compound

Use a large bucket and mixing paddle or industrial electric mixer to make sure the compound is the right consistency and free from lumps. Be sure to control the water and powder ratios and make sure the water is clean and cold. (Warm water will hinder how well the product works).

How thick can you lay a self levelling compound?

As self levelling cement is used on floors with an uneven surface of 5mm or less, the result isn’t usually more than an inch thick. However, some compound variants can offer a thickness of up to 5 inches.

FAQs

How do you lay a self levelling compound?

You either hire a professional to make sure you achieve the desired results or you follow our step-by-step guide above. Just note that the results are permanent and hard to remove, so be sure you’re confident in performing this task yourself before you do so.

How do you prepare a floor for self levelling compounds?

By cleaning, sweeping, vacuuming and priming it.

Do you PVA before self levelling?

There’s no need to use a PVA before you use a self levelling compound. However, it is advised that you clean and prime the surface before pouring over the cement mixture.

Can you lay self levelling compound in layers?

Yes, as long as you clean, prime and abrade the first layer.