Calcium sulphate grades for new Maldon homes
On a Wycke Hill drawing, the screed is usually written as a code such as CA-C25-F5. CA stands for calcium sulphate; after it, the C figure gives compressive strength while F gives flexural, each in N/mm2. You will meet three of them on Maldon plots: CA-C20-F4 for lightly used domestic rooms, CA-C25-F5 for the majority of houses, flats and offices, and CA-C30-F6 where floors take harder wear.
The developer's engineer decides the grade, and our job is to pour that exact grade and nothing else. A specification can also swap in an alpha hemihydrate screed, chosen for quicker drying or a thinner layer. In that case the manufacturer's own product sheet sets the depth and drying times, and we follow it ahead of any rule of thumb.
The material itself explains why it is specified. Calcium sulphate barely shrinks while it cures, so a Maldon open-plan ground floor or a whole flat level can go down as one wide bay with hardly any joints. Thresholds and the boundaries between heating zones may still need one, and we draw that layout up before pouring.
Flats form part of the picture: 11% of Maldon's homes are purpose-built flats, and a block floor laid in one visit over insulation and heating is exactly the work this screed does well. Our own team lays the insulation, membrane and perimeter strip, so the base under the pour is ours too. Our article on anhydrite screed explained gives more background on how it compares with cement.
Laitance, sanding and moisture tests in Maldon
While an anhydrite floor dries, a weak, powdery film called laitance rises to the top. Leave it in place and tile adhesive or compound grips that film instead of the screed, so it must be sanded away first. When the floor reaches the right dryness we sand it back and apply a primer made to work on calcium sulphate.
Then comes the moisture reading. Vinyl and wood suppliers tend to set a stricter moisture limit for calcium sulphate than for cement, so a Wycke Hill floor that seems dry underfoot may still fail their figure. Rather than trust the calendar, we take a hygrometer reading. If the floor is heated, the system can usually help dry it from about 7 days onwards.
There is one rule with no exceptions: keep calcium sulphate out of rooms where water may sit. So a shower, or a utility where the washing machine could leak, gets a cement based flowing screed instead, or in a small room a hand-laid sand and cement floor. In a newer Maldon house, check which screed each room already has before relaying one of them.
Anhydrite & Flow Screed prices in Maldon
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 Maldon
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 Maldon
Maldon is about 58.6 miles east-north-east of our Slough base as the crow flies, with postcodes including CM9. The nearest towns to it are Witham (5 miles), South Woodham Ferrers (6.5 miles), Chelmsford (8.8 miles) and Rochford (10.4 miles).
More on anhydrite screed, part of our screeding services.
