How to Price Floor Screeding: Sand-Cement vs Liquid Anhydrite, UFH Loading and Margin Guide

Quick Answer: Sand-cement floor screed prices £18–£32/m² supplied and laid for a typical 65–75mm bonded screed in 2026. Liquid anhydrite (calcium sulphate) flowing screed prices £24–£42/m² for the equivalent thickness. Underfloor heating loading adds £4–£9/m² for the screed itself (heat-shrinkage protection, additives) on top of the UFH installation cost. The single largest pricing variable is access — pumped delivery to a ground-floor extension is straightforward; barrowed wheelbarrow access to a sloping rear garden site can double the labour content.

Summary

Floor screeding is the unsung mid-stage of every wet-trade build. It happens after first-fix mechanical and electrical, after the slab cure, and before any floor finish. A fast, well-formed screed transforms a bumpy slab into a flat, true substrate ready for tile, LVT, carpet or wood. A slow, poorly-flat screed costs the customer time (waiting for cure), money (additional levelling compound) and thermal performance (UFH efficiency drops with screed quality).

The two dominant systems split on a clear axis. Sand-cement screed (the traditional choice) is hand-laid in 65–75mm thicknesses, takes days to dry, and demands skilled labour to achieve a true flat surface. Liquid anhydrite screed (Cemex Supaflo, Tarmac Topflow, Lafarge Agilia) is pumped in via tanker, self-levels to a fine SR1 finish without skilled trowelling, and dries faster — but costs 35–50% more per square metre and is incompatible with continuous moisture exposure (so unsuitable for bathrooms, wet rooms, plant rooms).

The UFH market has become the volume driver for liquid screed. Modern wet UFH systems benefit from the higher thermal conductivity of anhydrite (~1.8 W/mK vs ~1.2 W/mK for sand-cement), the thinner achievable depths (40–50mm cover over pipes vs 65–75mm for sand-cement), and the absence of micro-cracking. For a customer who's already paying £1,800–£3,500 for the UFH installation, the £400–£900 uplift to liquid screed is an easy upsell — and the right answer technically.

Key Facts

• Sand-cement screed (bonded) — 25–40mm thickness, £16–£26/m²
• Sand-cement screed (unbonded) — 50mm minimum, £18–£28/m²
• Sand-cement screed (floating, on insulation) — 75mm minimum, £22–£35/m²
• Sand-cement with UFH (floating) — 75mm minimum (50mm cover over pipes), £26–£40/m²
• Liquid anhydrite (gypsum) screed — 40mm cover over pipes minimum, £24–£38/m²
• Liquid anhydrite with UFH — 50mm depth typical, £28–£42/m²
• Liquid cement screed (Topflow C) — 40–60mm depth, £26–£40/m²
• Floor levelling compound (over screed) — £14–£24/m² for 3–8mm self-levelling
• Pump hire — £180–£420/day for liquid screed pump truck
• Drying time (sand-cement) — 1mm/day for first 50mm + 2mm/day above (typical 75mm = 28 days)
• Drying time (liquid anhydrite) — 1mm/day for first 40mm + 2mm/day above (typical 50mm = 25 days)
• Surface regularity (SR2 standard) — ±5mm under a 2m straightedge
• Surface regularity (SR1) — ±3mm under a 2m straightedge (typically achieved with liquid screeds)
• BS EN 13813:2002 — Screed material and floor screeds — Properties and requirements
• BS 8204-1:2003+A2:2011 — In situ floorings (concrete bases and cement sand levelling screeds)
• BS 8204-7:2003+A2:2011 — In situ floorings (pumpable self-smoothing screeds)
• DPM (damp-proof membrane) requirement — under all screeds on ground floors (BS 8204-1)

Quick Reference Table

Quick Reference: Screed Type Selection

Detailed Guidance

Sand-cement screed — the traditional choice

Sand-cement floor screed is mixed at 1:3 to 1:4.5 cement to sharp sand, with water content carefully controlled (target 7–10% by weight for hand-trowelled application). The mix is laid in panels separated by movement joints, levelled to falls or to a true flat using straight edges and timber battens, and trowelled finished.

Three configuration types under BS 8204-1:

• Bonded screed — laid directly onto the structural base with a primer or cement slurry. Minimum 25mm, typical 40mm. Strongest configuration but vulnerable to debonding if base prep is poor.
• Unbonded screed — laid over a slip layer (polythene, building paper) or an existing slab in poor condition. Minimum 50mm. Reduces base-bond risk but adds thickness.
• Floating screed — laid over a compressible insulation layer. Minimum 65mm without UFH, 75mm with UFH (50mm cover over pipes). Required for any UFH installation in sand-cement.

The drying time is the major workflow constraint. Standard rule: 1mm per day for first 50mm, 2mm per day for thickness above. A typical 75mm floating screed needs 28 days to dry to a moisture content suitable for impervious floor finishes (vinyl, LVT, wood). A self-levelling compound and tile on a partially-dried screed will lift or warp.

Liquid anhydrite (gypsum) screed — the UFH default

Liquid anhydrite screed is delivered ready-mixed in a tanker and pumped through a hose into the room. The mix is calcium sulphate (anhydrite) with water and additives, achieving SR1 finish (±3mm under a 2m straightedge) by self-levelling.

Key properties:

• Thermal conductivity ~1.8 W/mK (vs ~1.2 W/mK for sand-cement) — 50% better for UFH heat output
• Tensile bending strength higher than sand-cement equivalent — fewer movement joints needed
• Thinner cover over UFH pipes — 40mm minimum vs 50mm for sand-cement
• No micro-cracking in normal use — more reliable for hard floor finishes
• Faster install — pumped 80–150m²/day vs 25–45m²/day hand-laid
• Surface laitance — must be sanded off after 3–5 days before any floor finish

Limitations:

• Not for wet areas — bathrooms, wet rooms, kitchens with floor drains, plant rooms with continuous moisture exposure cause anhydrite to weaken and ettringite to form
• Not for direct chemical exposure — garages, workshops, food preparation areas with spillage
• Compatibility check for floor finish adhesives — many tile adhesives need a primer, vinyl adhesives need anhydrite-rated bond
• Surface laitance sanding required — additional cost and dust

For a typical kitchen extension with wet UFH, liquid anhydrite is the right answer. For a bathroom or utility room, sand-cement remains essential.

UFH integration — the design considerations

For wet UFH (water-fed system, the dominant residential type), the screed cover over the pipes determines:

• Heat-up time — thinner cover heats faster
• Energy efficiency — thinner cover delivers heat to the floor surface with less mass to warm
• Floor finish compatibility — engineered wood especially prefers low and consistent surface temperatures, achieved with thinner screed and lower flow temperatures

Minimum cover over UFH pipes:

• Sand-cement floating: 50mm above pipes (so 75mm total over insulation with 16mm pipe at base)
• Liquid anhydrite: 40mm above pipes (so 50–55mm total over insulation)
• Liquid cement: 40mm above pipes (so 50–55mm total)

For tiled finishes, a perimeter expansion strip at all wall-to-screed junctions is essential to allow thermal expansion. Fail to install this and the screed will crack at the wall edges and the tile will craze.

DPM and damp-proof requirement

BS 8204-1 requires a DPM under all screeds on ground floors. Polythene (1200 gauge minimum, typically 1500 gauge for screed work) is laid over the slab, lapped 150mm at joints, and turned up at perimeter walls.

Common errors:

• DPM not turned up to skirting height — moisture migrates around the perimeter
• DPM punctured by reinforcement chairs or trades work
• DPM omitted entirely — screed picks up rising moisture, floor finish fails

For a screed over insulation, the insulation typically sits on the DPM, with no separate slip layer needed (the polythene slip surface on the insulation acts as the bond breaker).

Surface regularity — what the customer is paying for

BS 8204-1 defines three surface regularity grades:

• SR1 — ±3mm under a 2m straightedge. Achievable with liquid anhydrite, very high-quality hand-laid sand-cement.
• SR2 — ±5mm under a 2m straightedge. Standard expectation for hand-laid sand-cement.
• SR3 — ±10mm under a 2m straightedge. Acceptable only for screeds receiving thick build-up (carpet, granular fill).

A "screed-only" finish for tile or LVT installation needs SR2 minimum; for vinyl sheet or thin linoleum, SR1 is preferred. If the screed is SR3, a self-levelling compound (£14–£24/m²) is needed before the floor finish — that's a £400–£900 additional cost on a typical kitchen.

Always specify the SR grade in the quote. "Screed to SR2 finish" is a clear deliverable; "screed to a flat finish" is not.

Drying time and moisture-test requirement

Floor finishes specify maximum residual moisture content for installation:

The hood test (BS 8203) measures equilibrium relative humidity at the screed surface — 75% RH is the standard threshold for impervious finishes.

Forced drying with dehumidifiers, heated air, or accelerated curing additives can reduce drying time but adds cost. For a 75mm sand-cement screed, natural drying takes 28 days; forced drying can compress this to 14–18 days at a cost of £300–£700.

Pricing structure — labour and material breakdown

For sand-cement (typical 75mm floating screed, 50m² area):

• Materials: cement, sharp sand, polythene DPM, perimeter strip, insulation (if not separately costed): £6–£10/m²
• Labour (2-person crew, 1 day for 50m²): £8–£14/m²
• Plant: pan mixer, wheelbarrows, trowels (amortised): £1–£2/m²
• Profit and overhead: £4–£6/m²
• Sell price: £22–£35/m²

For liquid anhydrite (typical 50mm with UFH, 50m² area):

• Materials: anhydrite screed delivered, perimeter strip, slip membrane: £14–£20/m²
• Labour (3-person crew for screed pour, 0.5 day for 50m²): £4–£7/m²
• Pump hire (proportionate): £3–£6/m²
• Profit and overhead: £6–£9/m²
• Sell price: £28–£42/m²

The liquid anhydrite premium comes from the material cost (calcium sulphate vs cement-and-sand commodity pricing) and the pump hire — but is offset by faster install (one day vs two days), thinner cover, and SR1 finish without trowelling skill.

Frequently Asked Questions

How much does floor screed cost per square metre 2026?

Sand-cement screed: £18–£32/m² supplied and laid for typical 65–75mm floating thickness. Liquid anhydrite screed: £24–£42/m² for 40–50mm thickness. The price includes materials, labour, DPM, perimeter strip, and (for liquid screed) the pump truck. Underfloor heating adds £4–£9/m² for screed loading on top of the UFH installation itself.

Sand-cement vs liquid screed — which is better?

Liquid anhydrite is the default choice for wet UFH installations in dry rooms (kitchens, living rooms, bedrooms) — better thermal conductivity, thinner cover, faster install, smoother finish. Sand-cement remains essential for wet areas (bathrooms, wet rooms), garages, plant rooms, and any space with continuous moisture or chemical exposure. Cost-wise, sand-cement is 30–40% cheaper but has worse thermal performance and slower install.

How long does floor screed take to dry?

Sand-cement: roughly 1mm/day for the first 50mm, 2mm/day for thickness above. A typical 75mm screed takes 28 days. Liquid anhydrite: 1mm/day for the first 40mm, 2mm/day above. A typical 50mm screed takes 25 days. Force-drying with dehumidifiers can compress this to 14–18 days at extra cost. Don't lay floor finishes until moisture content is verified at the BS 8203 threshold.

Can I lay tiles directly on a screed?

Yes, provided the screed is dry to the manufacturer's tolerance, has SR2 finish or better, and any laitance (especially on anhydrite) has been sanded and primed. For anhydrite screeds, a calcium-sulphate-compatible primer is essential before tile adhesive — most tile adhesives are cement-based and react badly with raw anhydrite surface. Sand-cement screeds need only a SBR primer or floor adhesive primer.

Why has my screed cracked along the wall edges?

Almost always omitted perimeter expansion strip. The screed expands and contracts with temperature (especially with UFH), and without an expansion strip at the perimeter, the stress concentrates at wall junctions and cracks. Fix is to chase out the crack to 6–10mm wide, fit a flexible perimeter foam strip (10mm), and re-fill or accept the crack as an aesthetic only (won't propagate further once the strip is fitted).

Regulations & Standards

• BS 8204-1:2003+A2:2011 — In situ floorings: Concrete bases and cement sand levelling screeds (sand-cement)

• BS 8204-2:2003+A2:2011 — In situ floorings: Concrete wearing surfaces

• BS 8204-7:2003+A2:2011 — In situ floorings: Pumpable self-smoothing screeds

• BS EN 13813:2002 — Screed material and floor screeds — Properties and requirements

• BS 8203:2017 — Code of practice for installation of resilient floor coverings (moisture testing)

• Building Regulations Approved Document C — Site preparation and resistance to contaminants and moisture (DPM requirement)

• Building Regulations Approved Document L1 — Conservation of fuel and power (insulation under floor)

• The Concrete Society — Floor Screeds — technical guidance

• BSI — BS 8204 series — primary technical standard

• Cemex — Supaflo liquid anhydrite technical data — manufacturer technical data

• Tarmac — Topflow Anhydrite technical data — manufacturer technical data

• GOV.UK — Approved Document C — DPM requirements

• UFH pricing where screed loading is one cost line — for the integrated cost picture

• bathroom installation including screed for tile substrate — for screed in wet-area context

• wood floor installation timing post-screed cure — for the floor finish workflow

• LVT installation needs SR1 substrate often via screed — for the substrate prep angle

• wet UFH installation including pipe spacing and screed cover — for the heating system itself