How to Price Wet Underfloor Heating: Manifold, Pipe and Screed Costs

Quick Answer: UK wet underfloor heating in 2026 prices £80–£140 per m² installed for in-screed (new build / new floor), £100–£170 per m² for low-profile retrofit systems over existing floor (e.g. ProWarm Lo-Pro, Polypipe Overlay), and £140–£220 per m² for retrofit between joists with foil/spreader plate systems. A typical 25 m² kitchen-diner installation runs £2,500–£4,200; a 60 m² ground floor £5,800–£9,500; a whole-house system £8,500–£18,000+. Heat pump-ready low-temperature design adds £15–£30 per m² over conventional design but reduces lifetime energy cost by 15–30%.

Summary

Wet underfloor heating (UFH) replaces or supplements radiator-fed central heating with PEX-Al-PEX or PEX pipework laid below the floor surface, distributing heat through warm water at 35–55°C. Compared to radiators, UFH delivers more even heat distribution, lower flow temperatures (better for condensing boiler efficiency and essential for heat pumps), and frees wall space. The trade-off is install cost — typically 2–4× radiator system cost for the same floor area — and slower response time.

Three install methods dominate UK domestic UFH: in-screed (pipe laid on insulation, screed poured over to 70–100 mm depth), low-profile overlay (proprietary panels with embedded pipework, 16–25 mm total build-up over existing floor), and between-joists (pipe with aluminium spreader plates fixed between floor joists, no floor build-up). The right method depends on floor type, ceiling height available, and whether the install is new build or retrofit.

For pricing, the per-m² rate is driven by labour and pipe cost (similar across systems) but build-up cost varies widely. In-screed adds the screed cost (£25–£45/m² for 75 mm sand-cement screed). Low-profile overlay panels are £35–£70/m² in materials. Between-joists is cheapest in materials (£20–£40/m²) but most labour-intensive. New-build in-screed is generally the lowest-cost-per-m² UFH option; retrofit is always more expensive for the same floor area.

Key Facts

• In-screed UFH (new build / new floor) — £80–£140 per m² installed
• Low-profile retrofit overlay — £100–£170 per m² installed
• Between-joists retrofit — £140–£220 per m² installed
• Wet UFH manifold (8-port, 6-zone capable) — £350–£650 supplied
• PEX-Al-PEX pipe — £1.20–£2.20 per linear m supplied (typically 6–10 m per m² floor area)
• PEX pipe (UFH grade) — £0.90–£1.60 per linear m
• Insulation board (PIR or EPS) — £8–£18 per m² supplied
• Sand-cement screed (75 mm pumped) — £25–£40 per m²
• Liquid screed (Anhydrite, 50 mm) — £35–£55 per m²
• Low-profile panel (Polypipe Overlay, ProWarm Lo-Pro) — £35–£70 per m² supplied
• Spreader plates (aluminium) — £8–£15 per m² supplied
• Mixing valve / blending valve — £180–£320 supplied
• Zone actuator — £40–£80 each
• Programmable thermostat per zone — £80–£180 supplied and fitted
• Programme — 2–5 days install for typical kitchen-diner; 5–10 days for whole ground floor
• Drying time before flooring — 7–28 days for sand-cement screed; 24–72 hours for liquid screed

Quick Reference Table

Detailed Guidance

In-Screed UFH — The Standard New-Build Approach

The dominant new-build UFH method in UK domestic construction:

1. Insulation board laid over slab or ground beam structure — typically 100 mm PIR (Celotex / Kingspan) or 150 mm EPS for U-value 0.18 W/m²K to L1A
2. Edge insulation strip around perimeter to prevent thermal bridging
3. Pipework clipped or stapled to insulation in serpentine pattern at 100, 150 or 200 mm centres
4. Manifold connections at one end of each circuit
5. Pressure test — typically 6 bar for 2 hours minimum
6. Screed poured at 75–100 mm depth (pump-applied for any volume above 20 m²)
7. Curing — 7–28 days for sand-cement (depending on thickness); 24–72 hours for liquid screed

For a typical 25 m² kitchen-diner:

• Insulation: 25 m² × £12 = £300
• Pipe (8 m/m² × 25 m² × £1.50): £300
• Manifold + valves + actuators: £450
• Pressure test and clipping labour: £250
• Screed: 25 m² × £30 = £750
• Total materials/screed: £2,050
• Labour for UFH installation: £750–£1,200
• Total fitted: £2,800–£3,250

Per-m² rate: £112–£130. This matches the £80–£140 typical range for in-screed.

Liquid (Anhydrite) Screed — Fast-Track Option

Anhydrite (calcium sulphate) liquid screed is the modern fast-track alternative to sand-cement screed:

• Pumped at 50 mm thickness (versus 75 mm for sand-cement)
• Self-levelling (no power-floating required)
• Cures in 24–72 hours to walkable; 7–14 days to floor-finishable
• Better thermal conductivity (~2.0 W/mK vs 1.4 W/mK for sand-cement) — improves heat transfer
• £35–£55 per m² supplied and pumped

The thinner screed reduces total build-up, useful in retrofit where ceiling height is limited. The faster cure shortens overall programme by 2–3 weeks.

Limitations: must not get wet during cure (rain protection essential); requires sealing primer before tile or vinyl flooring; not suitable in unheated rooms (can suffer from sulphate attack with prolonged dampness).

Low-Profile Overlay Systems — The Retrofit Standard

Where existing floor is in place and ceiling height matters, low-profile overlay panels are the dominant retrofit method.

Typical brands: Polypipe Overlay, ProWarm Lo-Pro, Wundatherm 16, Robbens System Tile.

Method:

1. Existing floor finish removed (carpet, vinyl, old tiles)
2. Existing floor inspected — must be flat to 5 mm tolerance
3. Levelling compound applied where needed
4. Proprietary low-profile panel laid (typically 16–25 mm thick total)
5. Pipework laid into routed channels in panel
6. Aluminium foil heat-spreader applied where panel design requires
7. Self-levelling screed (5–15 mm) over panels in some systems; floor finish direct on others

Typical 20 m² kitchen retrofit:

• Overlay panel: 20 × £55 = £1,100
• Pipe and connections: £200
• Manifold (smaller, 4-port): £350
• Levelling compound (where needed): £150
• Self-levelling overlay (where needed): £400
• Labour 2 days: £700–£950
• Total: £2,900–£3,250 = £145–£163/m²

The cost premium over in-screed reflects the manufactured panel cost. The advantage is build-up height (16–25 mm vs 100 mm) and faster install.

Between-Joists Retrofit

For suspended timber floors where the floor surface cannot be raised, pipework runs between joists with aluminium spreader plates.

Method:

1. Floor lifted (carpet, boards, sometimes flooring grade T&G chipboard)
2. Insulation pushed up between joists from below or installed from above
3. Aluminium spreader plates fixed to joist undersides or routed top surfaces
4. PEX pipe laid in spreader plate channels
5. Floor reinstated above

This is the most labour-intensive UFH method (typically 1.5–2× the labour of in-screed). Floor build-up is unchanged. Heat output is limited (50–80 W/m² vs 100+ W/m² in-screed) because of the air gap and non-direct contact.

Typical 25 m² retrofit:

• Spreader plates and clips: 25 × £12 = £300
• Pipe and manifold: £450
• Insulation: 25 × £15 = £375
• Floor lift and reinstate labour: £800–£1,200
• UFH labour: £900–£1,400
• Total: £2,825–£3,725 = £113–£149/m²

The labour proportion of cost makes between-joists slower per m² but cheaper in materials.

Manifold Selection and Zoning

The manifold distributes flow from boiler to the individual UFH circuits. Specification:

Standard manifold (4–8 ports) — covers most domestic projects. £350–£650 supplied. Includes: flow meters per circuit, isolation valves, automatic air vent, temperature gauges, fill/drain valves.

Premium manifold (8–12 ports, with mixing valve) — for whole-house or large installations. £500–£900 supplied. Includes integrated mixing valve, individual circuit flow meters, full electronic actuator readiness.

Zone control — actuators on each port allow individual room temperature control. £40–£80 per actuator. Wireless thermostat per zone £80–£180.

Mixing valve / blending valve — reduces boiler flow temperature (typically 70–80°C) to UFH operating temperature (35–55°C). £180–£320 supplied; included on premium manifolds.

For zoning decision:

• Single zone (whole UFH at one temperature): cheapest, suits open-plan kitchen-diner
• Multi-zone (room-by-room control): better comfort and energy efficiency, costs +£60–£140 per zone

Heat Pump Compatibility

Low-temperature UFH design is essential for heat pump systems:

• Conventional UFH design: 40–55°C flow temperature
• Heat-pump-optimised UFH: 35–45°C flow temperature

The lower operating temperature requires:

• Closer pipe centres (typically 100 mm vs 150–200 mm conventional)
• Higher insulation under pipework (typically 150 mm vs 100 mm)
• Lower-resistance flow path (manifold flow rate calculations)
• Larger manifold capacity for multi-zone operation

The cost premium for heat-pump-ready design is typically £15–£30 per m² over conventional UFH design. The justification is lifetime energy cost — a heat pump can deliver UFH at COP 3.5+, against COP 0.85 for an A-rated condensing gas boiler. Over a 20-year system life, the energy cost saving typically exceeds £8,000–£15,000 for a typical home.

Floor Coverings Over UFH

Each floor covering has different thermal resistance — important for heat output planning.

Best (lowest thermal resistance):

• Ceramic / porcelain tile: 0.01–0.02 m²K/W
• Polished concrete / screed: 0.001 m²K/W (essentially zero)
• Stone tile: 0.01–0.02 m²K/W

Acceptable:

• Engineered wood (12–18 mm): 0.10–0.15 m²K/W
• Vinyl (3–5 mm): 0.02–0.05 m²K/W

Marginal:

• Solid hardwood (over 18 mm): 0.18–0.25 m²K/W (some manufacturers void warranty)
• Carpet + thick underlay: 0.15–0.25 m²K/W

Avoid:

• Solid hardwood over 22 mm
• Heavy carpet with underlay over 7 mm
• Cork tile

For pricing, the floor finish must be confirmed before UFH design. A planned ceramic tile floor accepts smaller pipe centres (200 mm); a planned engineered wood floor needs tighter centres (100–150 mm) to achieve the same room output.

Frequently Asked Questions

Is wet UFH worth the extra cost over radiators?

For new builds, yes — the per-m² rate is comparable to a full radiator system on similar floor area, and UFH delivers superior comfort and frees wall space. For retrofit, it depends on floor type and finish. Concrete-floored properties and large open-plan kitchens make excellent UFH retrofit candidates; properties with valuable solid hardwood floors and limited ceiling height are usually better served by radiators.

Why does retrofit cost more than new-build?

Three reasons: (1) the existing floor finish must be removed and disposed; (2) build-up height is constrained, requiring more expensive low-profile systems; (3) labour for floor reinstatement adds 25–40%. New build pricing assumes a flat insulated slab ready for pipe; retrofit assumes everything must be undone and redone.

Can I install UFH myself?

Some homeowners do install pipework and panels themselves, but commissioning (pressure testing, balancing flows, mixing valve setup) requires specific equipment and knowledge. Most manufacturers offer DIY-friendly kits with clear instructions; the connection to boiler and electrical work to controls must be done by Gas Safe and Part P registered persons. DIY install with professional commissioning saves typically 20–35% versus full installer pricing.

How does UFH affect ceiling height?

In-screed: 75–100 mm build-up over insulation; typically loses 100–150 mm of ceiling height. Low-profile overlay: 16–25 mm. Between-joists: zero floor height impact. The decision often turns on this — a kitchen with 2.4 m existing ceiling height can absorb in-screed; a kitchen with 2.25 m may need low-profile.

How quickly does UFH heat up?

Slower than radiators. UFH thermal mass means room temperatures change slowly — 4–8 hours from cold to set point. This is best for steady-state operation rather than rapid heat-up. Most UFH systems run 24/7 with weather compensation rather than scheduled on/off, achieving comfort with lower flow temperatures.

Regulations & Standards

• Building Regulations Approved Document L1A and L1B — thermal performance, U-values

• Building Regulations Approved Document E — sound resistance through floors

• Building Regulations Approved Document P — electrical safety for controls and actuators

• BS 7593 — code of practice for treatment of heating system water

• BS EN 1264 — water-based surface heating and cooling systems

• BS EN 13813 — screed materials and floor screeds

• BS 8204-7 — installation of cementitious-based screeds for UFH

• PAS 2030/2035 — for funded retrofit work (ECO4, BUS, GBIS)

• Water Supply (Water Fittings) Regulations 1999 — water and heating system

• Polypipe Underfloor Heating — manufacturer technical specification

• Wundatherm — manufacturer specifications

• BSRIA — Underfloor Heating Guide BG 9 — industry technical guidance

• Energy Saving Trust — UFH — efficiency comparison data

• HHIC — heating sector guidance

• BS EN 1264-2 — UFH performance specification

• comparing UFH cost against radiator system — for the system comparison

• technical UFH installation methodology — for the on-site method

• UFH-with-heat-pump combined economics — for heat pump pairing

• low-temperature heating design principles — for design methodology

• UFH in bathroom installations — for bathroom-specific applications