Extruded vs expanded polystyrene: what are the key differences?
Both extruded polystyrene and expanded polystyrene are popular choices for insulation. Polystyrene’s high level of thermal resistance prevents heat from passing through.

Introduction
In this guide, we discuss the benefits of polystyrene as an effective insulation material and the key differences between extruded vs expanded polystyrene. We also provide a guide to the main benefits of each type of polystyrene.
Click on a link to jump to that section:
- Comparing extruded polystyrene and expanded polystyrene - Read the key differences between extruded polystyrene and expanded polystyrene insulation.
- Ravatherm XPS Flooring - Read the main benefits of Ravatherm XPS Flooring.
What is meant by expanded polystyrene (EPS) and extruded polystyrene insulation (XPS)?
Both materials are effective methods of insulation, sharing similar benefits. The main difference between the two lies in their method of production. XPS insulation is formed by melting together its core ingredients and extruding the resulting liquid. The material then expands whilst cooling, creating a tight, rigid insulation board. EPS polystyrene, on the other hand, is produced by heating small beads of polystyrene foam in a mould until they expand, fusing with one another in the process.
Visit our advice centre to find out more about extruded polystyrene.
Comparing extruded polystyrene and expanded polystyrene
Aside from differences in their method of production - there are other key differences between the two materials. Because of the larger gaps between the connected foam beads in EPS polystyrene – this means that EPS is less effective than XPS when it comes to thermal conductivity. XPS has a higher compressive strength than EPS and is able to support higher loads as a result.
In summary, some key benefits of extruded polystyrene include:
- XPS has a closed cell structure which means it is highly resistant to moisture.
- With a standard value of 300 Kpa, XPS insulation also boasts a high compressive strength.
- The thermal resistance (Also known as Lambda or ‘K’ Value) of XPS has an excellent value as low as 0.031 W/m.K.
- Extruded polystyrene is available with an ozone-depleting potential (ODP) of zero and a Global Warming Potential (GWP) of less than one.
- Increased strength. The manufacturing process of extruded polystyrene results in a closed cell structure which provides additional strength over other foam materials.
You can read more about the benefits of XPS Insulation here.
Ravatherm XPS Flooring
Ravatherm XPS polystyrene insulation is the market leader in extruded polystyrene solutions for below-concrete flooring insulation.
Ravatherm XPS X delivers improved thermal performance for flooring applications. The closed cell structure of Ravatherm makes it suitable for applications where the insulation material is directly exposed to a moist environment over a long period. The closed cell structure also gives the foam great rigidity and makes it highly resistant to compression. Ravatherm XPS X insulation is available in a range of compressive strengths to match the loading requirements of individual projects. These include domestic, commercial, and cold store/heavy duty applications. Ravatherm XPS X insulation can be installed under or over the slab in ground bearing concrete floors and is suitable for use with suspended beam and block and timber floors.
You can find out more about our Ravatherm XPS boards here.
Why work with Panel Systems?
Founded in 1974, Panel Systems has been supplying a variety of industry sectors for almost fifty years. Operating globally, we have earned ourselves a reputation for excellence that few other companies can hope to meet. We pride ourselves on our expertise, our capacity, and our colleagues in order to provide you with a supply partner you can depend upon. However large or small your business, we pledge to provide you with a solution to meet your specific requirements.
Get in touch
If you have any queries about finding the best insulation solution for you - contact Panel Systems today! Before specifying the use of Ravatherm XPS for your chosen application, please consult the manufacturers’ information and data sheets which can be found here.
Contact the team on 0114 275 2881 to discuss your specific requirements, or get in touch here.
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Get in touch to find out more about pricing, or to discuss your requirements in more detail.
Get in touch to find out more about pricing, or to discuss your requirements in more detail.
Call us on 0114 249 5626
