Screeding a concrete floor will ensure your floor’s foundations are level, strong and ready for laying flooring. Discover how to screed floors in our step-by-step guide, together with when levelling is necessary, the best formulas to use and how to ensure the screed is waterproof.
Solid foundations are essential for any type of flooring. It’s no different for indoor floors being covered with tiles, lino, wood or carpet.
Adding a thin layer of screed before laying your flooring will help to ensure the area is fully level and the foundation for your project is stable.
Screed is a concrete-like mix that is smoother than traditional concrete. Applying screed is a way of levelling the area so it’s ready to install the final layer of flooring.
Is screed just sand and cement?
Although floor screed formulas are similar to concrete, they contain a much smoother mix.
The formula itself is often a mixture of sand (or aggregate) and cement. The ratio of these two ingredients depend on your required smoothness. Typical sand and cement screed is a 1:5 or 1:6 ratio with sharp sand and cement.
Ready-made screed mixtures often contain extra additives to improve their formulas. For example, they may dry more quickly, feature improved strength or be able to be used on top of an underfloor heating system, as is the case with UltraFloor’s Screed IT Ultracem and Larsen’s Self Levelling Compound (SLC) 1500.
Buying a premixed formula for floor screed can save you the hassle and concern about compiling a homemade mix that may fail.
How to screed a floor
Follow our step-by-step guide on how to level – or screed – an indoor floor. Always read the manufacturer’s instructions for the formula you’re using.
Step 1: Divide the floor into sections
Divide the area to be levelled into sections using wooden dividers. Once broken up into sections you can more easily ensure your floor will be evenly screeded.
Many screeding products, like Instarmac’s UltraFloor Screed-IT, set rapidly. Make sure each area is a manageable size to avoid any issues.
The floor must be completely clear of dust and debris.
Step 2: Apply the screed
Follow the manufacturer’s instructions to mix the screed and apply a layer to the existing surface.
Spread the mixture with a trowel and compact it with a screeding board.
Step 3: Level the screed
Level the screeding formula by using a straight edge to create a flat surface.
Note: if your screed is self-levelling, like Larsen’s SLC 1500, you may not need to spend extra time smoothing it out yourself.
Step 4: Repeat for each section and fill the gaps
Next you’ll need to repeat the screeding process for each remaining section of your floor. Remove the wooden dividers and fill any remaining gaps.
Step 5: Float the screed
Once the screed has been applied throughout your area, you are then ready to float the screed to achieve a smoother finish.
Step 6: Allow the leveller to cure
Finally, allow the screed to set based on the manufacturer’s recommendations. As an example, it may take a few hours for light foot traffic and up to two days for full traffic.
You’ll need to allow more curing time before the final flooring is installed. Depending on your type of floor covering, some can be installed within as little as 1–2 days.
Do I need to screed a concrete floor?
Deciding whether or not to screed a concrete floor depends on how the floor will be used.
It’s likely you’ll need to screed a concrete floor if there is going to be another layer of flooring applied on top of it. This could be a carpet, flooring tiles (such as porcelain, ceramic or natural stone tiles), wood flooring or lino.
How long does floor screed take to dry?
Drying times for floor screed vary based on the dimensions and condition of your flooring project. The type of screed you use will also dictate how long it takes to dry.
As a levelling compound, floor screed is used as a base for flooring. Depending on how you will be using the floor will determine the thickness of the screed. And a thicker screed will have a longer setting time.
Some floor screeds, such as products from UltraFloor and Larsen, can be walked on in less than 3 hours. Floor coverings can often be installed within 1–2 days.
Bulk deals on floor levellers
Can you paint latex floor screed?
Latex floor screed is an alternative to traditional cement-based formulas. Latex formulas have a much smoother nature.
Be aware, a latex floor screed must have a wear course. It’s best to seek some advice from the product’s manufacturer before using it to screed.
Is screed waterproof?
Generally speaking, screed is not waterproof. If you are preparing a screed to prevent water ingress, you must also install a damp proof membrane, especially when installing flooring for a bathroom or wet room.
The layer of waterproof membrane can either be installed underneath or on top of the screed. This membrane will also add an extra adhesive layer within the flooring installation.
Find out more about floor levellers
For more info about levelling floors with screeds, get in touch with our family-run team on 0330 122 1025.
Here at the Paving Experts, we offer great deals for bulk buys with next day delivery throughout mainland UK.
