Floor Screeding

Sand & cement or liquid screed: which does your floor need?

Sand and cement screed suits wet rooms, falls, phased jobs and budgets — a robust hand-laid screed at 65–75 millimetres. Liquid anhydrite screed suits speed, large open areas and underfloor heating, flowing thinner and tighter around pipes. Neither is universally better; the room, the programme and the floor covering decide.

Sand and cement is the one to choose when the floor needs to do something: fall to a drain in a wet room, step between zones, or go down area by area as a renovation allows — and it shrugs off damp conditions, where calcium sulphate screeds need careful detailing and tanking. Liquid screed earns its premium on open-plan ground floors: pumped in a morning, self-levelled to an excellent surface, and wrapped tight around every underfloor heating pipe without the voids hand compaction can leave. The trade-offs are honest ones — higher cost, no falls, and laitance to sand off before tiling. We'll price both where both are viable.

What does floor screeding cost per m² in 2026?

In 2026, traditional sand and cement screed costs around £18–£28 per square metre laid in Surrey, and liquid anhydrite screed around £25–£40 per square metre pumped and levelled. Latex self-levelling compound for sub-5mm corrections over an existing sound floor runs cheaper still, priced by bag coverage and prep.

What moves the number: depth beyond the standard build-up, access (a pump needs somewhere to park; barrowed sand and cement costs labour), insulation and membrane layers below the screed, and job size — small areas carry minimum charges. Perimeter strips, day joints and movement joints are included in our price, not surprises on the invoice. For developers we price measured per square metre across plots and phases, the same way we handle commercial plastering packages; for a homeowner's extension we quote fixed from a site visit, with the drying programme written in so your flooring dates are real ones.

How long does screed take to dry before flooring?

Sand and cement screed dries at roughly one millimetre per day for the first 40 millimetres, then noticeably slower — so a standard 65–75mm screed realistically needs two to three months to be ready for sensitive coverings. Tiles can often go down sooner; wood and vinyl must wait for a passed moisture test.

That timetable is the most common source of programme pain on extensions. Drying can't be rushed with blasted heat — forced drying cracks and curls a young screed — but steady ventilation, background warmth and early sanding of a liquid screed's laitance all genuinely help. Before wood, vinyl or any moisture-sensitive floor goes down we test rather than estimate: a surface hygrometer reading below 75% relative humidity is the benchmark the flooring trades work to. Where an old solid floor shows persistent moisture from below, the fix sits under the screed — a proper membrane detailed in with the damp-proofing and replastering work at the wall junctions.

Screeding over underfloor heating: what matters

Over underfloor heating, the screed must wrap every pipe without voids, cover them at the right depth, and be commissioned gently — a gradual temperature ramp over days, done before the final floor goes down, never after. Liquid anhydrite screed is often the best choice here: it flows around pipes and runs thinner, so the floor responds faster.

Voids are the enemy — an air pocket against a pipe insulates exactly where you want conduction — which is why pumped liquid screed has become the default over dense pipe layouts, and why thinner cover means a room that warms sooner and runs at gentler temperatures. Commissioning is the step that protects everything: the first warm-up must be staged in small daily increments up to working temperature and back down, relieving stresses before the floor finish locks the surface in. We coordinate that ramp with your installer and won't sign the floor off for covering until it's done.

How flat is flat? Levels, tolerances and falls

A good screed should sit within a few millimetres under a two-metre straightedge — the flatness class the flooring trades expect for tiles, boards and vinyl. We work to laser levels and check as we go, because flatness is laid in, not sanded on afterwards. Falls, where needed, are designed and formed deliberately.

Flatness matters more as finishes get less forgiving: large-format tiles telegraph every hollow, wide engineered boards rock on high spots, vinyl shows a trowel mark through its whole life. Where an existing slab is sound but wavy, a latex self-levelling pass at up to 5 millimetres is often the economical fix rather than a full re-screed. Levels also have to agree with everything around them — thresholds, stair bottoms, kitchen plinths and the plasterboard line — so we like screeding sequenced properly with the dry lining and boarding, setting datums from the finished floor level backwards.