Anhydrite grades for Rochford apartments and Hall Road plots
On an apartment drawing for Rochford, calcium sulphate screed appears as a strength code. Take CA-C25-F5: CA is calcium sulphate, the C25 gives compressive strength and the F5 flexural strength, each measured in N/mm2.
Most Rochford plots use one of three. CA-C20-F4 suits domestic rooms with light use, CA-C25-F5 goes under the majority of homes, apartments and offices, and CA-C30-F6 is kept for floors that take more punishment. Whether it is a block of flats or a single Hall Road plot, the engineer chooses the grade, and that exact grade is what goes in.
If a developer wants a quicker drying or thinner floor, the drawings may name an alpha hemihydrate screed instead. We then follow the manufacturer's data sheet for its depth and drying.
The reason developers choose calcium sulphate is its low shrinkage. It lets a Rochford apartment level go down in one visit as a few wide bays, over insulation or heating, with very few joints. Any joints that are needed, say at a threshold or where one heating zone meets the next, are mapped out ahead of the pour. Everything underneath the screed is laid by our own team first.
In a newer Rochford house, the original screed may already be anhydrite, which affects how any repair or relay is done, so the existing material is checked before a patch or a new floor is planned. Our anhydrite screed explained article gives the background on the material.
Laitance, moisture and wet rooms in Rochford
As an anhydrite floor dries, a soft, fragile film called laitance comes up to the surface. If it stays, the adhesive sticks to that film rather than to the screed, and the finish can let go, so it is sanded away before any flooring goes down. Sanding happens once the screed is dry enough to work, followed by a primer suited to calcium sulphate.
Testing follows. Each reading is compared with the limit set by the maker of your chosen flooring, and for calcium sulphate that limit is often lower than for cement. A hygrometer gives the readings, and our advice on drying and laitance is handed over on paper. Where pipes run through it, warming the floor from about day 7 can usually hurry the drying along.
Anywhere water might collect is off limits for calcium sulphate. A Rochford wet room, shower or utility gets a flowing screed with a cement binder, or traditional screed packed by hand if the room is small. If an older anhydrite floor needs patching rather than replacing, our screed repairs service can assess it. We also pour to specification for anhydrite screed in Basildon.
Anhydrite & Flow Screed prices in Rochford
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 Rochford
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 Rochford
On the map, Rochford sits east of Slough, about 58.4 miles from our base in a straight line (postcodes including SS4), next to Southend-on-Sea (2.9 miles), Rayleigh (4.4 miles), South Woodham Ferrers (5.7 miles) and Wickford (8.3 miles).
More on anhydrite screed, part of our screeding services.