When specifying a project, it’s important to understand the properties, benefits and uses of the material before installing it. XPS insulation is highly beneficial for a number of projects and uses so understanding these will help you to choose the right material for every project. In particular, XPS insulation is used as part of underfloor heating systems so, this article will explain why it’s practical for this use and the properties that make it particularly beneficial for this purpose.

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What is XPS insulation?

XPS (Extruded Polystyrene) foam is manufactured from polystyrene beads which, together with additives and a blowing agent, are fed into an extruder. Extrusion is a continuous process which results in a smooth skin on the top and bottom of each insulation board and also a closed cell structure which provides resistance to moisture.

Why is XPS insulation used for underfloor heating?

XPS insulation has many applications and can be used in domestic or commercial settings. Thanks to its high compressive strength and insulating properties, it is an ideal choice to compliment your choice of underfloor heating system. 

It has become popular for this application due to its high compressive strength and effective insulating properties. XPS can also be easily CNC routed to create the perfect material for laying pipes in water-based underfloor heating systems. 

Water-based underfloor heating systems

When XPS insulation is used for water-based underfloor heating systems, grooves are cut into the insulation using CNC (Computer Numerical Control) machining, creating the ideal space for the water pipes to sit in. 

The material is also extremely lightweight which makes it easy to install and straightforward to cut with hand tools where necessary. With long term thermal performance, it can help to increase the efficiency of underfloor heating.

Electric matting underfloor heating systems

XPS insulation can also be used in conjunction with electric matting underfloor heating systems. In this function, the electric matting is installed above the XPS floor insulation. The XPS will then reduce heat loss through the floor structure of each room.

For this application, the XPS insulation is hot-wire cut into thin sheets which are generally supplied in either a 6 or 10mm thickness. At this thickness, the sheets are space saving, whilst still providing a good standard of insulation.

Properties of XPS insulation

XPS insulation has a number of properties which are appropriate for use as insulation for underfloor heating systems. 

Moisture resistant

XPS floor insulation has a closed cell structure which makes it highly resistant to moisture, making it perfect for use in floor applications.

When compared directly with EPS (expanded polystyrene insulation), due to its beaded construction, EPS can allow water penetration, which over time causes the degradation of the overall performance of the insulation. This is especially important to take into account when considering materials for underfloor heating, as moisture may come into contact with the insulation at some point. 

High compressive strength

With a standard value of 300 Kpa, XPS insulation also boasts a high compressive strength. Thanks to its closed cell structure created during the manufacturing process, it provides extra support for the flooring placed over the top of it. XPS floor insulation has the strength to support most kinds of flooring and will continue to perform well under typical loads and foot traffic. 

This helps to maintain longevity making it a better choice than other types of foam insulation with lower compressive strength. 

Excellent thermal properties

Another exceptional quality of XPS floor insulation is its thermal properties.

The thermal resistance (Also known as Lambda or ‘K’ Value) of XPS has an excellent value as low as 0.031 W/m.K  The lower the value, the better the product is at insulating This helps the underfloor heating system to perform at its optimum level. 


Ravatherm XPS X uses environmentally friendly blowing agents in its manufacturing process, This means it boasts an ozone-depleting potential (ODP) of zero and a Global Warming Potential (GWP) of less than one.

Why choose Panel Systems?

Panel Systems provide full support from the beginning of a project, through to fitting. Our team are experts when it comes to XPS floor insulation for underfloor heating purposes. The team can handle bespoke projects from smaller orders to large scale requirements. 

With an in-house CAD design and CNC machining service, we can deliver excellence every step of the way, to make sure every project is specified and completed to the proper requirements and on-time. 

As suppliers of the material and cutting service, our in-house team is able to cater to a range of bespoke projects, as well as standard sizes. 

This also means that any changes to the specifications can be handled with ease and efficiency. With an end-to-end service, you can be sure of a fast and hassle-free service that will work with the needs of your project. 

For further information and data sheets for the Ravatherm XPS material we supply
please visit the downloads section of our website.

Get in touch to discuss your needs and to find out how we can help you.