Anhydrite specifications on Stotfold's new build plots
For a new house off Taylors Road or Arlesey Road, the engineer chooses the calcium sulphate grade and that is what we pour. The code comes from European screed rules: the figure after C is compressive strength, the one after F is flexural strength, and both are in N/mm2.
Three grades cover most homes. CA-C20-F4 covers rooms in a house that see little wear. Typical homes, flats and offices are poured at CA-C25-F5. CA-C30-F6 is for heavier use, and a larger building may call for different grades in different areas.
Now and again the plans list an alpha hemihydrate product in place of a grade. They are picked when the programme needs quicker drying or the floor has to be thinner, and every one has its own sheet setting depth and drying. We work to that sheet.
The material shrinks very little. That lets a through kitchen and living area on the ground floor, or a whole flat, be poured as broad bays with very few joints. Purpose-built flats account for 8% of Stotfold's homes, and their floors suit this material well.
We set out any joints beforehand, usually at doorways or where heating zones divide. Insulation, edge strip and the rest of the build-up are put down by our own team. A base that needs attention first is handled by our floor preparation service. Background reading is in our anhydrite screed explained guide.
Laitance, primers and moisture in Stotfold homes
On top of drying anhydrite a flimsy layer appears, called laitance. Glue will not stick to it reliably, so we sand it off before the flooring goes down. With that layer removed, a primer suited to calcium sulphate goes on so the next adhesive or compound grips firmly.
Next we check how much moisture is left. Calcium sulphate is often held to a tighter moisture figure by flooring makers than cement is, and a floor can look dry and still be over it. We test with a hygrometer and work to the limit your flooring maker gives, not to a date on the calendar. With heating pipes in the floor, the system can generally help dry it from roughly day 7.
Calcium sulphate does not belong anywhere that water could lie on the floor. That rules it out for a utility room, a walk-in shower or a wet room, which get a cement based flowing screed or a traditional Stotfold sand and cement screed laid by hand. For projects to the north, see anhydrite flow screed in Biggleswade.
Anhydrite & Flow Screed prices in Stotfold
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 Stotfold
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 Stotfold
Stotfold is about 37.9 miles north-north-east of our Slough base as the crow flies, with postcodes including SG5 and SG15. The nearest towns to it are Baldock (2.6 miles), Letchworth (2.7 miles), Hitchin (5 miles) and Biggleswade (5.1 miles).
More on anhydrite screed, part of our screeding services.
