Littlehampton flats and anhydrite screed grades
An apartment specification in Littlehampton may give the floor screed as CA-C25-F5. That code means calcium sulphate, with compressive and flexural strength of 25 and 5 N/mm2 respectively, under the European standard for screed materials.
Three grades turn up again and again. A lightly used domestic floor would carry CA-C20-F4. Houses, apartments and offices mostly get CA-C25-F5. Where the floor will take harder wear, the drawing will say CA-C30-F6.
Some designers name an alpha hemihydrate product instead, to dry the floor sooner or keep it thinner, and that product is laid to its own sheet, not to general rules. If a specification names one, we pour that product to its sheet; we do not swap it for a cheaper grade, and if a substitute is ever proposed it should go back to the designer first.
Anhydrite barely shrinks, so a wide area goes down in one bay with hardly any joints, a good fit for flats with open-plan living rooms. We plan the bay and joint layout before pouring, including joints at doorways and heating zone boundaries where the design needs them.
Only 8% of homes were built between 2000 and 2014, so new blocks are only part of the picture. A CA grade can just as well appear on the drawings for refurbishing an existing block. To read more about the material, see what anhydrite screed is.
Laitance, moisture and wet areas on Littlehampton projects
While anhydrite dries, a soft film called laitance builds up on top. It must be sanded off before flooring, or adhesives and compounds will bond to that weak skin and fail. After sanding, a primer made for calcium sulphate goes on. We can do both steps as part of our floor preparation work.
Moisture testing is stricter too. Flooring makers often allow less moisture in calcium sulphate than in a cement floor. Test with a hygrometer and check the result against the flooring maker's figure, not a general number. Force drying with underfloor heating can start from about 7 days, and good ventilation helps the floor give up its water.
The main limit is water. Keep anhydrite out of any room where water can reach the floor, which rules out wet rooms and some utility areas. In those rooms we pump a flowing cement screed instead, which ends up just as level. If you simply want a fast, flat floor and no grade is specified, our liquid screed page for Littlehampton is the better starting point.
Anhydrite & Flow Screed prices in Littlehampton
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 Littlehampton
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 Littlehampton
As the crow flies, our yard in Slough is about 50.2 miles from Littlehampton, which lies to the south. Postcodes here include BN17, and Bognor Regis (6 miles), Worthing (7.4 miles), Chichester (10.6 miles) and Shoreham-by-Sea (11.8 miles) are close by.
More on anhydrite screed, part of our screeding services.
