Specifying anhydrite for Acton and North Acton blocks
On an Acton block's drawings, the screed shows up as a code from the European screed materials standard. Read C as compressive strength and F as flexural strength, both given in N/mm2. A lightly used domestic floor takes CA-C20-F4, while CA-C25-F5 covers the bulk of homes, apartments and offices. Shops or offices on the ground floor of a block get CA-C30-F6, the grade for harder wear.
On the new blocks at North Acton and Acton Gardens, the grade is set by the engineer and we pour that designation, not a substitute. Where drawings say only "flow screed", we ask for the designation before pricing, so the grade is confirmed well ahead of the pour. Where a specification names an alpha hemihydrate product, chosen for drying speed or a thin section, we follow its product sheet.
The appeal of calcium sulphate on an apartment floor is low shrinkage. That lets us pour broad bays with only a few joints, and it sets to a flat, dense finish. Joints are still set at thresholds, between heating zones and at changes in plan, and we fix the bay and joint layout before the pour. Our own team prepares the build-up underneath, whether that is insulation, an acoustic layer or a membrane over concrete; for those layers see insulation and membranes.
If you are meeting an anhydrite specification for the first time, anhydrite screed explained covers the basics.
Sanding, priming and moisture testing on Ealing floors
As calcium sulphate dries, a fragile film called laitance comes to the top. Left in place, it gives adhesives a crumbly surface to grip. When moisture levels allow, our team sands that film away and seals the floor with a calcium sulphate compatible primer, after which the flooring contractor can carry out their own checks.
Moisture is tested with a hygrometer. Calcium sulphate is often given a stricter moisture limit than cement screed by flooring makers, so the reading must clear the number set for your particular finish. In a heated North Acton flat, the system can normally help dry the floor from about day 7, as long as it is turned up slowly.
Water is the one thing calcium sulphate does not tolerate over time. For showers, wet rooms and a leak-prone utility, we switch to a cement based flowing screed, or to a hand-laid Ealing screed sloped to the drain.
In one of Ealing's converted flats, the acoustic floor design and the screed type have to be agreed together, since both affect depth and weight.
Anhydrite & Flow Screed prices in Ealing
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 Ealing
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 Ealing
Ealing is about 14.3 miles east of our Slough base as the crow flies, with postcodes including W3, W4, UB1 and UB6. The nearest towns to it are Hounslow (3.5 miles), Brent (3.5 miles), Hammersmith and Fulham (4.4 miles) and Richmond upon Thames (4.9 miles).
More on anhydrite screed, part of our screeding services.
