Reading a Newham apartment specification: CA grades
Calcium sulphate screeds are graded under the European screed standard, and the code on the drawing tells everyone on site what the finished floor must achieve, so it is worth knowing how to read it. The figure after the C is the crushing, or compressive, strength and the figure after the F the bending, or flexural, strength, each read in N/mm2. Three grades cover most housing. CA-C20-F4 sits at the bottom, fine for a home where the floor sees little wear. Next up, CA-C25-F5 is the grade normally drawn for a typical house, flat or office. Floors that will be worked harder get CA-C30-F6.
On the Stratford, Canning Town and Royal Docks towers, the grade is chosen by the developer's engineer, and what goes into the floor must match that drawing exactly. If the design has a thin section or needs to dry fast, it may name an alpha hemihydrate screed. Each of those comes with its own data sheet setting the depth, drying and heating rules, and where it differs from the usual guidance, the sheet wins.
The material itself behaves differently from cement. Because it hardly shrinks while curing, it can go down in wide bays with very few joints, which suits the open plan flats and long landings in these blocks. Where joints are needed, over door thresholds, between heating zones or at changes in the structure below, the bay and joint layout is agreed before the pour.
For background on how it is made and why it differs from cement based screed, read anhydrite screed explained.
Laitance and moisture tests in Royal Docks apartments
Pumping it in gets you halfway. While the screed dries, a soft, chalky film called laitance comes up to the top. We sand that film away before any adhesive or compound is applied, and then seal the floor with a primer that is compatible with this binder. Skip either step and tiles or LVT can lift months later.
After that the floor needs a moisture test. A hygrometer figure that would pass on a cement floor can still be too wet for anhydrite, because many flooring manufacturers set a tighter limit for it. The date for flooring comes from a hygrometer, whatever the programme says. Where pipes run under the apartment floor, switching the heating on from about day 7 usually helps pull the moisture out, which buys time on a tight fit out.
Wet rooms and shower areas in these flats are a different matter. Calcium sulphate should be kept away from any floor that could get wet, so there we pour a cement based flowing screed, or lay a sand and cement floor for wet areas. When the finish needs an SR1 surface, a skim of self levelling compound over the sanded screed is the final step.
Anhydrite & Flow Screed prices in Newham
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 Newham
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 Newham
Newham is about 29.3 miles east of our Slough base as the crow flies, with postcodes including E6, E16, E7 and E12. The nearest towns to it are Tower Hamlets (3.2 miles), Greenwich (3.7 miles), Barking and Dagenham (4 miles) and Redbridge (4.1 miles).
More on anhydrite screed, part of our screeding services.