Anhydrite grades for Farnborough apartments and offices
Calcium sulphate screed is classified under the European screed standard. Its name gives two strength figures in N/mm2: C for compressive and F for flexural. For most Farnborough floors one of three grades applies:
CA-C20-F4, lighter duty, meant for homes where traffic is light.
CA-C25-F5, specified in most dwellings, from semis to flats, and in office buildings.
CA-C30-F6, where floors work harder.
For an apartment block, the middle grade is the usual specification. In Farnborough, where the town centre redevelopment is planned to add new homes, the flats will need screeds that meet sound insulation requirements between dwellings, so if calcium sulphate is specified there, it would normally float on an acoustic layer and insulation. The build-up under it is as important as the grade, and our own team prepares it.
Office and research buildings are another setting. Cody Technology Park beside Farnborough Airport has plans submitted for new and refurbished space, and office floors are normally specified at CA-C25-F5, with CA-C30-F6 where use is heavier. Our commercial screeding work covers larger floors like these.
Where a job needs quicker drying or a thinner section, alpha hemihydrate products are another route. Each has its own product sheet, and we lay to the one the specification names.
With so little shrinkage, calcium sulphate can be laid in big bays with few joints, and we set out that layout ahead of the pour. Wherever water could reach the floor, a flowing cement screed is used in its place.
Sanding, testing and priming anhydrite in Farnborough
Two jobs follow every calcium sulphate pour, and both come before flooring.
The first is laitance. Curing leaves a thin, weak skin on top of the screed. Adhesive, primer and levelling compound cannot be relied on to grip it, so when the floor is dry we sand it back to a clean, open surface and prime it with a calcium sulphate compatible product. That order matters: sanding before the floor is dry simply exposes more wet material.
The second is moisture testing. Calcium sulphate often has to reach a lower moisture level than a cement based screed before flooring makers will accept it. Only a hygrometer reading compared with the limit your flooring maker publishes tells you reliably. Counting days is not enough, especially in a cold building or one without heating running.
Heated floors speed this up. If heating pipes are in, the heating can usually start force drying it at about 7 days, stepped up gradually; heated floor screeds in Farnborough covers commissioning. For the general drying rates, see the guide to how long screed takes to dry, and for a full explanation of the material, read the anhydrite screed guide.
Anhydrite & Flow Screed prices in Farnborough
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 Farnborough
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 Farnborough
Farnborough is about 17.4 miles south-south-west of our Slough base as the crow flies, with postcodes including GU14 and GU11. The nearest towns to it are Frimley (1.8 miles), Aldershot (2.8 miles), Camberley (3.4 miles) and Fleet (3.9 miles).
More on anhydrite screed, part of our screeding services.
