Dunstable apartment floors and calcium sulphate grades
Anhydrite screeds are specified by strength class. Under the European standard for screed materials, a designation such as CA-C25-F5 gives the compressive strength (C) and the flexural strength (F) in N/mm2. You will mostly meet three: CA-C20-F4 where domestic traffic is light, CA-C25-F5 in typical homes, apartments and offices, and CA-C30-F6 where use is heavier. A drawing may name an alpha hemihydrate product instead when the floor must dry quickly or be thin, and its own product sheet then applies.
On a Dunstable apartment block, the engineer decides the grade and we pour exactly that. The material barely shrinks, which lets wide apartment bays go down with few joints, and it closes completely round heating pipes. Doorways and boundaries between heating zones still get joints, set out and agreed ahead of pouring. On a new block, the grade, depth and bay layout usually appear together on the engineer's drawing, and we confirm each one before the pump arrives.
A single flat being refitted may have no engineer's specification at all. In that case the grade is chosen from the floor's use and its finish, and written down before the pour. Luton, 4.6 miles away, uses the same grades, as our Luton anhydrite screed page shows.
For the general pumping and access side, see liquid screed for Dunstable floors.
Laitance, moisture and primers on Dunstable floors
With calcium sulphate, the pour is not the end of the job. Drying brings a fragile skin to the surface, known as laitance. Left in place, it is what adhesive or compound sticks to instead of the screed proper, and the flooring can come loose. So once drying allows, the skin is sanded back, the dust vacuumed away and a calcium sulphate primer goes on.
Moisture testing comes next. The dryness a flooring manufacturer demands from calcium sulphate is frequently stricter than for cement. A hygrometer test tells us whether the floor has reached that limit, rather than guessing from the number of days. Where the floor has heating, switching it on from around day 7 can usually hurry the drying along.
Wet areas are the exception. A walk-in shower, a wet room or a utility floor that could get wet should have a cement based screed instead, poured as a flowing mix or hand-laid in sand and cement. Our explainer on anhydrite screed goes deeper into the material.
Our written handover covers drying and laitance, so your flooring fitter can see exactly what was done and on which dates.
Anhydrite & Flow Screed prices in Dunstable
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 Dunstable
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 Dunstable
On the map, Dunstable sits north of Slough, about 25.1 miles from our base in a straight line (postcodes including LU6 and LU5), next to Houghton Regis (1.3 miles), Luton (4.6 miles), Leighton Buzzard (6.2 miles) and Flitwick (8.1 miles).
More on anhydrite screed, part of our screeding services.
