Choosing an anhydrite grade for Bromley apartments
Each calcium sulphate screed has a strength code under the European screed standard, printed on the drawings. Read the C figure as compressive strength and the F figure as flexural strength; both are N/mm2. CA-C20-F4 covers a quiet domestic room. Step up to CA-C25-F5 and you have the grade written into the drawings for most homes, apartments and offices. CA-C30-F6 is kept for heavier use, such as a busy corridor or a commercial ground floor below flats.
If your Bromley block or plot comes with an engineer's specification, we pour exactly the grade it names and nothing else. An architect squeezed for floor height, or for time, may name an alpha hemihydrate product, which dries sooner or goes down thinner. Depth and drying for those come from the product's own data, and the pour follows it.
Its strong point in a Bromley apartment is how little it moves while curing, so an open-plan flat or a broad ground floor can be poured in big bays and cut with only a few joints. Joints are still planned across door thresholds, between heating zones and where the floor changes shape, and we set that layout before the pour, not on the day.
Brand new housing is a small share of the borough, with 4% of homes built since 2015, so a calcium sulphate specification here may just as easily come from a conversion or extension as from a new plot. Our own team prepares the full build-up first; see insulation and membranes.
Laitance, moisture tests and wet areas in Bromley
While it dries, a thin skin known as laitance rises to the surface. It is weak, and it must be removed. When the moisture level allows, we sand that skin away and seal the floor with a primer designed for calcium sulphate, since the wrong primer can let go. Leave the laitance on and a tiled or LVT floor can come loose months down the line.
Moisture is the next check. Flooring manufacturers commonly set calcium sulphate a stricter moisture ceiling than cement screed, which means a reading that passes on sand and cement may fail on anhydrite. A hygrometer check comes before any flooring is booked in. Where underfloor heating is in, it can normally be used to speed drying from about day 7, raised step by step.
The limit of the material is water. Keep it out of wet rooms, shower areas and any utility room that could flood. Those floors get a cement based flowing screed instead, or Bromley hand-laid cement screed shaped to fall to the drain.
Our plain guide to anhydrite goes into how it behaves in more depth.
Anhydrite & Flow Screed prices in Bromley
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 Bromley
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 Bromley
On the map, Bromley sits east-south-east of Slough, about 31.8 miles from our base in a straight line (postcodes including SE20, BR3, TN16 and BR1), next to Swanley (5.5 miles), Lewisham (5.7 miles), Croydon (5.8 miles) and Bexley (6.9 miles).
More on anhydrite screed, part of our screeding services.