What anhydrite grade codes mean for Clacton-on-Sea floors
Every anhydrite order for a Clacton-on-Sea job starts from a code such as CA-C20-F4. The two letters at the front say the binder is calcium sulphate. C20 gives the crushing strength and F4 the bending strength, each in newtons per square millimetre, as the screed materials standard defines them.
A chalet home or inter-war bungalow with ordinary family traffic is the kind of light domestic floor that CA-C20-F4 is aimed at. CA-C25-F5 is the all-round grade for houses, apartments and offices, and CA-C30-F6 is kept for floors that work harder. Whichever line the CO15 or CO16 drawing carries is the mix we order, with no substitutions on the day.
Alpha hemihydrate mixes sit outside that ladder. They earn their place when a Clacton room has limited height to spare above the insulation or the programme wants the floor dry sooner, and each brand's data sheet fixes its own depth and drying rules.
Why pick calcium sulphate at all for a bungalow being relaid? Its shrinkage is very small, so a bungalow's whole floor area can often be poured in wide bays with hardly any joints. We draw the bay plan before the lorry arrives, placing joints at doorways and where heating zones change.
Thinking about a conservatory or garden room on one of the newer estates at the edge of town? The Clacton underfloor heating screed page covers pipe cover, and the same grades are poured for anhydrite flow screed in Colchester.
Getting a Clacton-on-Sea anhydrite floor ready for flooring
A fresh anhydrite floor in a Clacton flat or bungalow still has three jobs ahead before vinyl, tiles or wood go down.
Clearing the laitance. While it cures, a thin, chalky layer rises to the surface. When the screed is dry it is sanded off and the dust vacuumed, because adhesive spread over that layer clings to it and not to the solid floor. Our floor preparation team can take this on if your fitter will not.
Proving it is dry. Flooring makers often allow less moisture in calcium sulphate than in a cement screed, so a reading that would pass on one can fail on the other. A hygrometer settles it, with the covering's own limit the final word. Where there are pipes, warming the floor from about seven days can speed things up.
Priming it. A primer designed for calcium sulphate goes on before cement based adhesive or compound.
Water is the one thing it will not tolerate. With 17% of Clacton homes in purpose-built blocks, many floors in town belong to flats, and where one of those has a shower area or a plant room, that part takes a cement based flowing screed instead. Drying and laitance notes are handed over in writing.
Anhydrite & Flow Screed prices in Clacton-on-Sea
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 Clacton-on-Sea
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 Clacton-on-Sea
On the map, Clacton-on-Sea sits east-north-east of Slough, about 79.3 miles from our base in a straight line (postcodes including CO15 and CO16), next to Colchester (12.9 miles), Maldon (20.8 miles), Witham (22 miles) and Rochford (24 miles).
More on anhydrite screed, part of our screeding services.
