Underfloor Heating Pipe

Shop high-quality underfloor heating pipe for water underfloor heating installations. We stock flexible and durable PEX and PE-RT pipe for new-build, retrofit, domestic and commercial heating systems.

Available in a choice of pipe diameters and coil lengths, our range includes options for both traditional screeded systems and low-profile underfloor heating. Whether you are installing a complete system or extending an existing one, you can select the pipe size and coil length required for your project.

Underfloor Heating Pipe Sizes

Choosing the correct pipe size will depend on the system design, floor construction and required heat output. Our range includes:

• 9.9mm pipe – designed for selected ultra-low-profile retrofit systems
• 12mm pipe – suitable for low-profile underfloor heating installations
• 16mm x 2mm pipe – the most widely used size for domestic water underfloor heating
• 20mm pipe – suitable for larger floor areas and selected commercial applications

Coil lengths range from 50m to 500m, allowing you to choose a suitable quantity while helping to minimise unnecessary joints and waste.

PEX and PE-RT Underfloor Heating Pipe

PEX and PE-RT are flexible plastic pipes designed to circulate warm water through an underfloor heating system. Their flexibility makes them easier to form into heating circuits, while their durability makes them suitable for long-term installation within screeded and low-profile floor constructions.

Many products also feature an oxygen barrier, which helps reduce oxygen entering the heating system and protects compatible metal components against corrosion. Always check the individual product specification before ordering.

Underfloor Heating Pipe for New Build and Retrofit Projects

Standard 16mm pipe is commonly used in new-build and traditional screeded installations. Where floor height is limited, smaller-diameter pipe can be used with a compatible low-profile system to reduce the overall floor build-up.

Pipe size, circuit length and spacing should always follow the underfloor heating design. Correctly designed circuits help provide balanced water flow, consistent floor temperatures and efficient heat distribution.

Underfloor Heating Pipe from Trusted Brands

Underfloor Store supplies underfloor heating pipe from established manufacturers including Uponor and Warmup. Please check the individual product page for compatibility, operating limits, warranty information and approved fittings.

If you require a complete system rather than individual components, explore our water underfloor heating packs.

Underfloor Heating Pipe FAQs

What size pipe is normally used for underfloor heating?

For many domestic water underfloor heating systems, 16mm x 2mm is the standard pipe size. Smaller 9.9mm and 12mm pipes are generally used in compatible low-profile systems, while 20mm pipe may be specified for larger or commercial installations.

How much underfloor heating pipe do I need?

The quantity required depends on the heated floor area, pipe spacing and circuit design. The pipe should be divided into appropriately sized circuits rather than installed as one continuous loop. Always follow the system design and the manufacturer’s maximum circuit-length guidance.

Can underfloor heating pipe be joined beneath the floor?

Underfloor heating circuits should ideally be installed in continuous lengths without joints beneath the finished floor. Selecting the correct coil length helps reduce waste and avoids unnecessary concealed connections.

How long does underfloor heating pipe last?

Quality underfloor heating pipe is designed for long-term use when correctly specified and installed within its operating limits. Warranty periods vary between manufacturers and products, so check the individual listing for full details.

Can I use any pipe with my underfloor heating system?

No. Pipe diameter, fittings and system components must be compatible. If you are replacing or extending existing pipework, check the manufacturer, pipe dimensions and fitting requirements before ordering.