Specifying CA grades for Stratford-upon-Avon new builds
Calcium sulphate screeds are classed under the European standard for screed materials by a designation such as CA-C25-F5. Read it in three parts: CA for the calcium sulphate binder, then C and F for compressive and flexural strength in N/mm2. Three grades are in common use. The lightest, CA-C20-F4, is for homes where floors see little wear. Stratford houses, flats and offices generally take the middle grade, CA-C25-F5. Where a Stratford floor will be worked hard, CA-C30-F6 is specified.
On a developer's plot at Shottery, Bishopton or Loxley Road, the grade comes from the engineer's specification and that is what we pour, without swapping in something else. Occasionally the engineer writes in alpha hemihydrate instead, for its quicker drying or slimmer section. With those, the manufacturer's data sheet sets the minimum depth and the drying time, and the usual rules of thumb give way to it.
Low shrinkage is why the material suits big floors. Large bays can be poured with few joints, which keeps an open-plan ground floor or an apartment level free of breaks in the finish. Where joints are needed, the bay and joint layout is planned and agreed before pouring.
Underneath, the insulation, membrane and edge strip are laid by our crew, so the base is one we have checked with our own eyes before any screed arrives. Our anhydrite screed guide covers how the material behaves in more depth.
Laitance, moisture and wet areas in Stratford-upon-Avon flats
Drying calcium sulphate throws up laitance, a feeble crust on its upper face. Adhesive laid onto it bonds to the skin rather than the screed, and that is how tiles and LVT come loose months later. Once the Stratford flat floor is dry enough we sand that crust off and seal it with a calcium sulphate primer. Primers meant for cement are not always compatible.
Moisture is the second check. Flooring makers often allow less moisture in calcium sulphate than in cement screed, which is how a floor that seems dry to the touch can still fail their test. Our hygrometer gives the answer; a calendar cannot. If the flat has underfloor heating, force drying can normally begin at about 7 days and take time off the programme, with the warm-up explained on our Stratford heated floor screed page.
Anywhere a floor might stay damp is the wrong place for calcium sulphate. For a shower room in a Stratford flat, or a downstairs utility that might see a leak, use a cement based flowing screed or a hand-laid sand and cement floor for wet rooms instead. If you simply want a pumped floor for an extension and no specification is involved, liquid screed in Stratford-upon-Avon is the more relevant page.
Anhydrite & Flow Screed prices in Stratford-upon-Avon
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 Stratford-upon-Avon
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 Stratford-upon-Avon
On the map, Stratford-upon-Avon sits north-west of Slough, about 64.4 miles from our base in a straight line (postcodes including CV37), next to Warwick (8 miles), Royal Leamington Spa (10 miles), Kenilworth (11.7 miles) and Evesham (12.4 miles).
More on anhydrite screed, part of our screeding services.
