Anhydrite vs Cement Liquid Screed: Gyvlon or Cemfloor?

Gyvlon and Cemfloor are both pump-applied liquid screeds, but they use different binders. Gyvlon is an anhydrite screed made with a calcium sulphate binder, and Cemfloor is a cement-based screed. Both are used in homes and commercial buildings, including over underfloor heating, and the right one depends on your floor build-up, depth, floor finish and build programme.

Cotswold Flow Screed installs both, supplied pre-mixed through our partner Flowmix, across Gloucestershire, Worcestershire, Warwickshire and the Cotswolds from our base in Evesham. This guide explains how they differ and how to choose between them.

Two types of liquid screed

All liquid screeds are poured rather than laid by hand, and they level themselves across the floor. What sets them apart is the binder that holds the screed together:

• Anhydrite screed uses calcium sulphate, which is why it is also called calcium sulphate or gypsum-based screed.
• Cement-based liquid screed uses cement, like traditional sand and cement screed, but in a flowing mix that is pumped into place.

The binder affects how each screed is prepared for floor finishes, which areas it suits and how it is looked after once poured.

Gyvlon anhydrite screed

Gyvlon is an anhydrite liquid screed used on projects ranging from single rooms to large commercial buildings. It was developed to work with underfloor heating, and a range of additive options is available depending on the project.

Gyvlon is often chosen for:

• extensions, new builds and renovations with warm-water underfloor heating
• large or open-plan floor areas
• internal floors that will stay dry once the building is finished

Anhydrite screed is commonly sanded after it has cured to remove the surface laitance, so the floor finish can bond to it properly.

Cemfloor cement screed

Cemfloor is a cement-based liquid screed. It gives you the flowing, self-levelling application of a liquid screed with a cement binder.

Cemfloor is often chosen for:

• projects where an anhydrite screed is not suitable or not specified
• areas where the floor may be exposed to moisture
• floors where height is tight, using Cemfloor Level Plus

Cemfloor Level Plus is a version of Cemfloor designed for projects with restricted depth, including some renovations where raising the floor is difficult.

Gyvlon and Cemfloor side by side

Binder

• Gyvlon: calcium sulphate (anhydrite)
• Cemfloor: cement

Typical projects

• Gyvlon: homes and commercial buildings, especially internal floors with underfloor heating
• Cemfloor: homes and commercial buildings, including areas where an anhydrite screed is not suitable

Underfloor heating

• Gyvlon: commonly used, and developed to work with underfloor heating
• Cemfloor: commonly used, with Level Plus available where depth is limited

Surface preparation

• Gyvlon: commonly sanded to remove laitance before the floor finish
• Cemfloor: may need sanding depending on the product and floor finish

Floor finishes

• Gyvlon: adhesives and primers need to be approved for calcium sulphate screeds
• Cemfloor: compatible with standard cement-based adhesive systems in most cases

This comparison describes how the two products differ, not which is better. The right choice depends on your project.

Which works with underfloor heating?

Both do. Liquid screed is commonly used with warm-water underfloor heating because it flows around the pipework, and both Gyvlon and Cemfloor are used this way. The depth over the pipes depends on the product and the floor build-up, and the team will confirm it for your project.

See our guide to liquid screed for underfloor heating for how the floor build-up fits together.

Floor finishes: tiles, timber and vinyl

Whichever screed you choose, the floor finish needs a prepared, dry surface before it goes down. The main difference is in preparation and adhesives:

• Tiles: on anhydrite screed, use a primer and adhesive their manufacturer approves for calcium sulphate screeds.
• Timber and engineered boards: check moisture levels and the board manufacturer's requirements for the screed type.
• Vinyl, LVT and carpet: these usually need a smoothing compound and a dry screed, whichever product is used.

Your floor-finish supplier's instructions take priority. The team can advise on screed preparation, including sanding.

How to choose

You do not need to choose a product before you ask for a quote. The team will recommend one based on your answers to a few questions:

1. Is underfloor heating being installed, and what type?
2. How much depth is available between the base and the finished floor level?
3. What floor finish are you planning to lay?
4. Will any area be exposed to moisture once the building is finished?
5. Has your architect or builder already specified a product?
6. What does your build programme look like after the pour?

Product choice also affects the price. See our guide to how much liquid screed costs for the other factors that make up a quote.

Get a quote for Gyvlon or Cemfloor screed

Cotswold Flow Screed covers Gloucestershire, Worcestershire, Warwickshire and the Cotswolds from Evesham. Send your location, floor area, screed depth if known, whether underfloor heating is involved and any product your plans specify, and the team will come back with a recommendation and a quote. Request a quote online or call 01386 577010.