Specifying calcium sulphate for Brentwood apartment floors
Look on a Brentwood apartment specification and the screed will be written as a string of letters and numbers set by the European screed standard. Read the C number as resistance to crushing and the F number as resistance to bending, both given in N/mm2. Bedrooms and other quiet domestic floors can take CA-C20-F4. Step up to CA-C25-F5 and you have the usual grade for houses, apartments and offices alike, while CA-C30-F6 is reserved for floors that will be worked harder.
Grade choice on a block sits with the developer or their engineer, not with us; whatever is written is what arrives in the lorry. Where depth is limited or the programme is short, the designer might name an alpha hemihydrate product; that comes with its own data sheet setting depth and drying times, and we stick to it.
Because it shrinks so little while setting, this screed can go down in large bays with few joints. Over an acoustic layer in a Brentwood apartment, a single continuous pour is easier to protect than a patchwork of small bays. Doorways and boundaries between heating zones still need joints, and we set out where they go before pouring.
Grades are written into the drawings most often on new build plots, and the biggest scheme in Brentwood's planned growth is the proposed Dunton garden settlement of up to 6,000 homes. To read more about the material, see our explainer on anhydrite screed.
Laitance, moisture and wet rooms in Brentwood flats
Drying calcium sulphate leaves a fragile surface film, known as laitance. Glue stuck to that film would fail with it, so when the screed has dried sufficiently we sand the film off and apply a primer intended for calcium sulphate. A cement primer will not do the same job.
Then comes moisture. Expect a stricter test. Plenty of flooring manufacturers want a drier calcium sulphate base than they would accept in cement, meaning a hygrometer figure good enough under tiles elsewhere might still hold the job up here. So on a Brentwood floor the calendar does not decide; a hygrometer reading does. Where pipes run through the screed, switching the heating on to speed drying is normally allowed from around day 7.
There is one firm rule: keep it out of floors that may stay wet. In a Brentwood flat, the shower room with a walk-in tray, any wet room and a utility room where a leak could sit all call for a cement based flowing screed or a traditional hand-laid floor, since water left standing on calcium sulphate weakens it. For a thin smoothing coat over the dried screed before sheet flooring, see our latex smoothing screed.
Anhydrite & Flow Screed prices in Brentwood
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 Brentwood
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 Brentwood
As the crow flies, our yard in Slough is about 41.4 miles from Brentwood, which lies to the east. Postcodes here include CM15, CM14 and CM13, and Billericay (4.8 miles), Havering (5.4 miles), Basildon (7.2 miles) and Stanford-le-Hope (9.1 miles) are close by.
More on anhydrite screed, part of our screeding services.
