Anhydrite grades for Walton-on-Thames apartments and plots
Calcium sulphate screeds carry a designation that sets out their strength. Take CA-C25-F5. CA stands for calcium sulphate, C25 for 25 N/mm2 of compressive strength and F5 for 5 N/mm2 of flexural strength. Three grades cover most buildings. Light domestic rooms get CA-C20-F4. For the run of homes, flats and offices, CA-C25-F5 is standard. Busier floors go a grade higher with CA-C30-F6.
Apartment floors, like those in the 279 flats at The Heart of Walton, usually sit over acoustic insulation, and a calcium sulphate screed suits that build-up. It shrinks very little, so large bays need few joints, and it can float on the insulation layer to cut sound between flats. Joints at thresholds or between heating zones are set out before the pour.
New houses are the other fit. Walton gained 12% of its homes between 2000 and 2014, and builds from those years were often drawn with calcium sulphate flow screed already in the plan.
A tight programme or a shallow floor may lead the designer to an alpha hemihydrate product, which is laid and dried to its maker's own sheet. We pour exactly what the specification names, and if the drawings leave the grade open we put a recommendation in writing for the designer to approve. The material is described in everyday terms in our anhydrite screed explainer.
Before flooring goes down on Walton-on-Thames anhydrite
Three steps sit between a poured anhydrite floor and a finished one.
First, the laitance. As calcium sulphate dries, a fine, weak skin forms on top. Glue will not grip that skin, so a sander takes it away once the screed has dried out enough.
Second, the moisture test. Flooring brands commonly let calcium sulphate hold less moisture than cement, which makes the pass mark tighter than most Walton flat owners would guess. A hygrometer gives the answer, not a count of days. Underfloor heating, where fitted, can usually be used to force dry it once about 7 days have passed.
Third, the primer. A primer suited to calcium sulphate goes on the sanded floor before adhesive or compound touches it. Some standard primers are not suitable.
One limit applies everywhere. Shower areas and wet rooms, where water can sit on the floor, never get calcium sulphate. Cement based flowing screed goes there, or traditional screed laid for wet rooms. Specifiers in the area can compare with our anhydrite screed in Addlestone.
Anhydrite & Flow Screed prices in Walton-on-Thames
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 Walton-on-Thames
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 Walton-on-Thames
As the crow flies, our yard in Slough is about 14.1 miles from Walton-on-Thames, which lies to the south-east. Postcodes here include KT12, TW17 and KT10, and Weybridge (2 miles), Sunbury-on-Thames (2.3 miles), Addlestone (3.4 miles) and Chertsey (3.7 miles) are close by.
More on anhydrite screed, part of our screeding services.