Reading an anhydrite specification for Aldershot plots
Anhydrite is the everyday name for calcium sulphate screed. On drawings it carries a code in which C gives compressive strength and F flexural strength, both measured in N/mm2. Light domestic floors get CA-C20-F4. Most Aldershot flats, houses and offices would sit at CA-C25-F5. Where floors take a heavier pounding, CA-C30-F6 is the grade. If a drawing names a grade, that is what we supply, and we will query it if the use of the room seems to call for something else.
Alpha hemihydrate screeds sit in a group of their own. People pick them to dry sooner or to lay thinner, and every one has its own data sheet setting thickness, drying and heating.
The real advantage is stability. Because it barely shrinks while curing, the bays can be large and the joints far fewer than in cement screed. Joints are still set out before pouring, with doorways and any change in the floor's shape looked at first.
Large new build programmes such as Wellesley, the Aldershot Urban Extension planned for 3,850 homes on former military land, are the type of project where plot specifications name a screed grade. For the wider picture on pumped screeds, see our Aldershot liquid screed page, and the anhydrite screed explainer covers the material in more depth.
Laitance, moisture and primers on Aldershot floors
The finishing steps are what separate a sound calcium sulphate floor from a failed one. While it cures, the surface grows a thin, weak crust called laitance. Once dry, that crust must be sanded off, because adhesive would grip the crust instead of the screed beneath, and the flooring could lift.
Moisture is the second trap. Flooring manufacturers often want calcium sulphate drier than they would accept for cement, so a moisture level a tiler would be happy with on cement can be too high in this material. A hygrometer test tells you where it stands; do not judge by how the surface looks. Open windows to keep air moving; where pipes run under the floor, the heating can generally be brought in from roughly day 7 to speed the drying.
Then comes the primer. Calcium sulphate needs one that is compatible with it, particularly under cement based tile adhesives, which should not go straight onto the screed.
Last of all, keep this material out of rooms where water could reach the floor. For bathrooms or plant rooms in a block, a cement based flowing screed gives similar speed without the sensitivity to water. Where a finished calcium sulphate floor is still uneven, levelling compound can bring it within tolerance.
Anhydrite & Flow Screed prices in Aldershot
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 Aldershot
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 Aldershot
As the crow flies, our yard in Slough is about 20.1 miles from Aldershot, which lies to the south-south-west. Postcodes here include GU11 and GU12, and Farnborough (2.8 miles), Farnham (2.9 miles), Fleet (4.1 miles) and Frimley (4.6 miles) are close by.
More on anhydrite screed, part of our screeding services.