Anhydrite Screed London — Supply & Installation
When should I choose Anhydrite screed?
Choose Anhydrite (calcium sulphate) screed when you need to cover very large areas in a single day. See our preparation guide for the pre-pour checklist before a large-area install. at the lowest cost per square metre. Up to 1,500 m² installed in one day, very low shrinkage, fully underfloor heating compatible. Avoid in wet rooms — choose Cemfloor there instead.
Anhydrite Screed (also known as Gypsum) is a type of floor screeding product that produces a finish very similar to sand and cement screeds — though lighter and it can appear almost white.
The main advantage is that it covers big areas — up to 1,500m² can be installed within a single day. It is also cheaper than most other screed types with very minimal shrinkage.
Note: Anhydrite Screed is sensitive to moisture. It should not be used in bathrooms, wet rooms, or any area with persistent moisture exposure.
Do you install Gyvlon screed?
Yes — Gyvlon is the calcium-sulphate (anhydrite) screed we pump most often, and we install the full Gyvlon range. It is delivered by mixer truck and pumped straight into place, the same as every screed we lay. Gyvlon, anhydrite screed and calcium-sulphate screed all describe the same family of product; Gyvlon is simply the proprietary binder we specify. It flows readily, self-levels to a fine finish and encases underfloor-heating pipes with almost no air voids, which is why it is a strong choice for large heated floors.
Should I choose Gyvlon (anhydrite) or Cemfloor (cement) screed?
Both are pump-applied liquid screeds that vastly outperform traditional sand-cement on speed and flatness. The binder decides where each one belongs.
Choose Gyvlon (calcium sulphate) for large, dry internal floors — open-plan living areas, bedrooms and commercial floor plates away from moisture. It covers ground quickly, pours thin over underfloor heating with excellent heat transfer, and is typically the lower-cost option per m². Its one trade-off: it forms a surface laitance that needs light sanding before some floor finishes, and it should not be used where there is permanent moisture.
Choose Cemfloor (cement) wherever moisture is a factor — bathrooms, wet rooms, kitchens, plant rooms and basements — or where you want to save a trade: Cemfloor leaves no laitance, so there is no sanding or depriming before floor finishes, it tiles with standard adhesives, and it can be force-dried to pull the programme forward.
Not sure which is right for your project? Send us the floor build-up, the location and whether underfloor heating is involved, and we will specify the correct screed — we install both. See our Cemfloor screed page for the full cement-screed detail.
What are the key specifications of Anhydrite screed?
Anhydrite screed is walkable in 24–48 hours, supports heavy loads after 7 days, and accepts most floor finishes within 14 days under good drying conditions. Recommended depths: 35 mm unbonded over insulation, 15 mm fully bonded, 40–50 mm over underfloor heating with 30 mm minimum cover above pipework.
- Light foot traffic within 24–48 hours
- Heavy loading capacity after 7 days
- Underfloor heating compatible
- 35mm depth on unbonded insulated floors
- 15mm depth on bonded installations
- Up to 1,500m² installed in a single day
For typical anhydrite screed installation costs in London and the South East, see our liquid screed cost guide.