Anhydrite grades on Cirencester new build plots
Look at a plot specification and the calcium sulphate screed will be named by a code from the European screed materials standard. Read its C figure as compressive strength and its F figure as flexural strength, each given in N/mm2. Three grades cover most housing work. For a home floor that sees little wear, CA-C20-F4 is enough. CA-C25-F5 is what you will see written for most houses, apartments and offices. Busier floors carrying heavier loads are specified at CA-C30-F6.
On a developer's plot, such as those planned at The Steadings, the engineer chooses the grade, and we pour exactly that rather than something near it. Where speed of drying or a slimmer section is the priority, a specification may call for an alpha hemihydrate product instead. With those, the manufacturer's data sheet fixes how deep to pour and how long it dries, and we stick to it.
The material has real advantages. Because it barely shrinks while setting, big bays need only a handful of joints, which is useful on an open-plan ground floor or right across an apartment. Any joints, say at a doorway or where one heating zone meets the next, are drawn up with the bay layout ahead of time instead of being decided mid-pour.
Apartments are a natural fit. Purpose-built flats make up 21% of Cirencester's homes, and an apartment floor in one of those blocks can go in during a single visit, over insulation and frequently over heating as well. More on what the material is can be found in our anhydrite screed guide.
Laitance and moisture checks on Cirencester floors
Calcium sulphate forms laitance as it cures, a thin and weak film on top. Adhesive and levelling compound cannot be relied on to grip that film, so after enough drying time we sand the film off and seal the surface with a primer suited to calcium sulphate.
Moisture is the other check. Flooring makers often set a tighter moisture figure for calcium sulphate than for cement, so anhydrite can fail a test that the same reading would clear under tiles on a cement screed. We test with a hygrometer, working to the limit the flooring maker sets for calcium sulphate rather than a general figure. Heated plots have an advantage here, because the system can usually be run to force dry the screed once roughly a week, about 7 days, has gone by.
There is one firm limit. Calcium sulphate is weakened by prolonged wetting, so it does not belong in wet rooms, walk-in showers or utility areas at risk of leaks. In a Cirencester wet room we would pour a flowing mix with a cement binder instead, or rule a sand and cement mix by hand. If an older base needs attention before the pour, see floor preparation. The same specification work is on our anhydrite page for Gloucester.
Anhydrite & Flow Screed prices in Cirencester
Liquid flowing screed (which includes anhydrite): £24 to £31 per m² supplied and laid (MyJobQuote, August 2026), so £960 to £1,240 for 40 m². MyJobQuote does not say whether these figures include VAT. See our floor screeding cost guide or screed calculator.
Who lays your anhydrite and flow screed in Cirencester
K & B Screeding’s own team, led by director Donatas Bardisevicius. Founded 2019, company 12298780.
See what customers say in our Google reviews and on our testimonials page.
Anhydrite & Flow Screed from Slough to Cirencester
As the crow flies, our yard in Slough is about 58.3 miles from Cirencester, which lies to the west-north-west. Postcodes here include GL7, and Stroud (10.9 miles), Royal Wootton Bassett (12.4 miles), Swindon (13.3 miles) and Cheltenham (13.5 miles) are close by.
More on anhydrite screed, part of our screeding services.
