Calcium sulphate specifications for Leicester apartments and plots
On an apartment scheme or a new build plot, calcium sulphate screed is usually written into the specification as a grade code. The letters and numbers mean something specific. CA stands for calcium sulphate. The number after C is the compressive strength and the number after F the flexural strength, measured in N/mm2.
Three grades cover most work. For homes with light traffic, CA-C20-F4 is enough. CA-C25-F5 is the usual grade for houses, apartments and offices. Floors that will take heavier use go up to CA-C30-F6. Whatever grade the drawings show is the one we pour, with no swaps.
A specification may instead name an alpha hemihydrate product. Those are picked when quicker drying or a thinner floor is needed, and each comes with its own product sheet for depth and drying, which we keep with the order.
The reason designers choose calcium sulphate for apartments is dimensional stability. Because it barely shrinks, it can go down in big bays with few joints and stays flat along long corridors and across open living areas. The bays and joints are set out before pouring, so joints land at doorways and heating zones and not across the middle of a room.
Flat conversions in older buildings can use the same material where the structure and build-up allow. For a plain English overview, read anhydrite screed explained, and for general pumped floors, our Leicester liquid screed page covers access and speed.
Laitance and moisture checks before Leicester floors are finished
With calcium sulphate, finishing the pour leaves half the job still to do. As it cures, a thin and weak surface skin called laitance forms, and it must be sanded off once the floor has dried. If it stays, adhesives and smoothing compounds grip the laitance instead of the screed, and floor coverings can come loose.
Moisture is the second check. Calcium sulphate is often held to a tighter moisture limit by flooring manufacturers than cement screed is, so a floor can look ready and still not be. Our hygrometer reading is checked against the limit the flooring maker sets. On a heated floor, force drying can usually begin from about 7 days, which cuts the wait a good deal.
Primers need care too. Before any cement based adhesive or compound goes on, the surface needs a primer that works with calcium sulphate. If LVT or sheet flooring needs an extra smooth base, our compound levelling work follows the same rule.
Not every room suits this material. A wet room, a plant room or any floor that might get wet should have a cement based flowing screed instead. We put our advice on drying and laitance in writing for the flooring contractor, so they know exactly what to do.
Anhydrite & Flow Screed prices in Leicester
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 Leicester
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 Leicester
On the map, Leicester sits north-north-west of Slough, about 78.9 miles from our base in a straight line (postcodes including LE1, LE2, LE3 and LE7), next to Earl Shilton (8.7 miles), Hinckley (12 miles), Lutterworth (12.7 miles) and Market Harborough (13.9 miles).
More on anhydrite screed, part of our screeding services.