When renovating a property in London or installing new flooring, it’s important to understand the difference between self-levelling compound and floor screed. Both are used to prepare a subfloor for finishes such as tiles, timber, vinyl or carpet, but they serve different purposes depending on the project.
What screed is
In UK construction, screed is a layer installed above a structural slab or insulation to create the correct floor height, strength, and level surface. Traditional screed is typically made from sand and cement, while liquid screed is a flowing alternative applied by pump. Screed is usually installed in thicker layers, generally 30mm or more, which makes it suitable for large floor areas and structural build-ups. It is also commonly used to cover underfloor heating systems.
What self-levelling compound does
Self-levelling compound is a cement-based mixture, often modified with polymers, designed to flow across the floor and fill small dips or irregularities. It is usually applied in thin layers, typically between 2mm and 15mm, and creates a very smooth surface ready for flooring. Because it sets quickly, it is often used when project timelines are tight.
Key differences at a glance
Thickness: Screed is used to build floor depth, while self-levelling compound corrects small surface variations.
Purpose: Screed forms a strong structural base; levelling compound provides a smooth finishing surface.
Installation and drying: Traditional screed takes longer to install and cure, while levelling compounds flow easily and often dry faster.
Typical applications: Screed is best for larger areas and underfloor heating systems, while levelling compounds suit smaller areas or minor corrections.
Practical guidance (London/UK)
If your subfloor is generally sound but slightly uneven, a levelling compound can provide a quick solution before installing tiles or timber flooring. For extensions, loft conversions, or projects involving underfloor heating, screed is usually the better choice.
Why choose Floor Screeding London?
With over 15 years of experience, Floor Screeding London installs traditional screed, liquid screed, and self-levelling systems across London with reliable results.