Concept view of AD-EPS400 foil-faced overlay panels with multilayer heating pipe

Water underfloor heating solution

AD-EPS400 Low-Profile Foil-Faced Overlay System

Lightweight water underfloor heating for renovations where the existing structural floor is staying in place.

AD-EPS400 uses 20mm foil-faced panels with ready-made channels for the heating pipe. Install it over a suitable prepared floor without a traditional full screed, then add the layers required for your chosen floor finish.

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The system behind the solution

Choose Your AD-EPS400 Kit

Foil-topped grooved EPS panels hold the pipe in a low-profile overlay. Choose a standard kit or ask our team to check your floor and finish.

Adept AD-EPS400 underfloor heating kit with foil-faced panels, heating pipe, manifold, pump and controls
A low-profile overlay system

Foil-topped panels, pipe and controls vary by kit size.

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Choose a standard kit

Select the heated area that matches your project.

Kit size

15m² kit contents vary by size. Review the full kit details before ordering.

Selected kit
£878.99 inc. VAT
Unsure of the right size or zoning? See full kit contents and specifications

Get an AD-EPS400 project design

Get an AD-EPS400 Design for Your Project

Send us your plans, floor details and chosen covering. We can help check the build-up and specify the panels, pipe circuits, manifold and controls.

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AD-EPS400 foil-faced floor panels with heating pipe installed around a room and doorway

Installation overview

How AD-EPS400 Is Installed

Plan the panel and pipe routes before fitting. Follow the project design and current installation instructions:

  1. 1Confirm heat loss, manifold position, circuit lengths, panel layout and the floor-finish build-up.
  2. 2Prepare a clean, dry, level and structurally suitable base.
  3. 3Fit the panels using the fixing, bonding or underlay method specified for the floor.
  4. 4Cut panels to fit, align the channels and apply the specified aluminium tape across joints.
  5. 5Press the 16 × 2mm pipe into the channels, following the planned circuit routes.
  6. 6Connect, fill and pressure-test before adding the approved preparation layer and floor finish.
Heating pipe laid in AD-EPS400 foil-faced panels, showing return bends in a compact room

Understanding the panel

How the Foil-Faced Panels Work

The panels combine insulation, pipe channels and a heat-spreading foil surface in one lightweight layer. The main practical benefits are:

  • Foil helps spread heat across the panel surface.
  • Routed channels hold the pipe at 150mm centres without separate clips.
  • Lightweight panels are straightforward to handle and cut.
  • The overlay avoids a traditional full screed; upper layers depend on the floor finish.

Plan the complete installation

Where AD-EPS400 Works Best

Consider AD-EPS400 for renovations and extensions where a suitable existing floor will remain and a lightweight overlay is preferred. Compare the overlay systems if you are still choosing.

  • Renovations and extensions over an existing floor.
  • Suitable solid, screeded or beam-and-block floors.
  • Suitable suspended timber or battened floor constructions.
  • Projects needing a lightweight alternative to a full screed.
Typical AD-EPS400 floor build-up showing panels and heating pipe over a timber floor with an upper covering layer

Typical AD-EPS400 Floor Build-Up

A typical build-up runs from the existing floor to the final covering as shown below. Include the preparation layer or underlay only where specified for your chosen finish.

  1. 1Sound, dry, level and structurally suitable existing floor
  2. 2Specified fixing, bonding or underlay method
  3. 320mm foil-faced EPS400 panels
  4. 416 × 2mm heating pipe in the 150mm channels
  5. 5Preparation layer or underlay where required by the chosen floor finish
  6. 6Compatible final floor finish
20mm
Foil-faced EPS400 panel
16 × 2mm
WRAS-approved PEX-AL-PEX pipe
150mm
Pre-routed pipe centres
1200 × 600mm
Individual panel format

AD-EPS400 project advice

Frequently Asked Questions

Clear answers about panel height, heating pipe, suitable floors and floor finishes for AD-EPS400 projects.

What is the AD-EPS400 underfloor heating system?

AD-EPS400 is a low-profile warm-water underfloor heating system using 20mm pre-routed, foil-faced EPS400 panels. The panels position 16 × 2mm PEX-AL-PEX pipe at consistent 150mm centres.

What does EPS400 mean?

EPS is expanded polystyrene. EPS400 identifies the dense panel grade used to create the lightweight routed insulation layer within the system.

How much floor height does AD-EPS400 add?

The EPS400 panel is 20mm thick. The complete finished increase also includes the approved fixing or bonding method, underlay, plywood or self-levelling compound where required, and the selected floor covering.

What pipe is used with AD-EPS400?

The system uses WRAS-approved 16 × 2mm PEX-AL-PEX multilayer heating pipe supplied in 100m coils. The project design determines the final circuit layout and quantity of pipe.

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Which existing floors can AD-EPS400 be installed over?

AD-EPS400 can be considered over suitable solid, screeded, beam-and-block, suspended timber and battened floors. The base must be clean, dry, level and structurally suitable for the specified installation method.

Which floor finishes can be used with AD-EPS400?

Laminate and approved engineered wood may be laid as a floating floor directly above the panels, with any underlay specified by the flooring manufacturer.

Tiles, vinyl and carpet need the specified preparation layer, such as 6mm plywood or a suitable self-levelling compound. Confirm the complete method for your covering with the flooring, adhesive and preparation-product manufacturers.

Why is the EPS400 panel foil-faced?

The aluminium foil facing helps distribute heat across the panel surface. It works with the pre-routed channels, which retain the heating pipe at the planned 150mm spacing.

How do I choose the correct AD-EPS400 kit?

Start with your heated area, room layout, existing floor, available height, floor covering and number of zones. The design should confirm panel quantities, pipe circuits, manifold size and controls.

Browse AD-EPS400 kits to check the available sizes and contents, or request a quote for help specifying your system.