Where to use SOPRA XPS insulation in the building envelope

SOPRA XPS is an industry-leading range of C2C certified high-performance and sustainable XPS (extruded polystyrene) insulation rigid boards from Soprema. It offers long-term strength and durability due to its closed-cell structure that prevents water penetrating the structure of the XPS insulation board.

Well-known for its exceptionally high compressive strength, high dimensional stability, excellent moisture-resistance, low thermal conductivity, and consistent low lambda values year after year, SOPRA XPS insulation has a wide variety of applications in the building envelope.

Applications for SOPRA XPS insulation

Highly moisture resistant, lightweight and easy to install, SOPRA XPS insulation is suitable for inverted roofs, roof gardens (green, blue, brown and solar roofs) and zero-fall roofs as well as flooring and below-ground structures such as external basement walls. In Ireland, it’s typically found in hotel roof gardens, terraces or podium areas and basement car parks in apartment complexes.

SOPRA XPS insulation was used as part of Soprema’s inverted roof system build-up on the green roof terraces at the award-winning Grant Thornton headquarters in Dublin together with Soprema’s DUOFLEX hotmelt structural waterproofing. It’s also specified in many different applications throughout the National Children’s Hospital, including floors, roofs, podium decks and terracing areas.

Considering compressive strength

Because SOPRA XPS insulation is available in a range of compressive strengths, architects and specifiers can choose the most appropriate boards based on whether the surface will have pedestrian traffic or cars passing over it. Soprema’s range of XPS insulation includes SOPRA XPS SL, SOPRA XPS 500 and SOPRA XPS 700. SOPRA XPS 500 and SOPRA XPS 700 names refer to the respective compressive strengths of the boards, as measured in kPa. SOPRA XPS 500 is mainly used as thermal insulation under slabs, or concrete floors in underground car parks. Boards with lighter kPa are more suitable for standard flooring bearing lighter loads such as pedestrian traffic. SOPRA XPS SL is used on flat roofs together with a Soprema waterproofing system and ROOF 115, a water draining, vapour-permeable, separating and protecting layer. 

Providing a full inverted roof buildup

The SOPRA range of XPS insulation products are fully compatible with Soprema roofing and waterproofing systems. This means Soprema is the only supplier in Ireland that can provide a full inverted roof system build-up entirely from within our own set of solutions. This is a benefit to designers or specifiers, who only need to deal with a single supplier for this aspect of the project, and for technical support.

How to calculate true thermal performance

Another factor for specifiers to consider is a board’s thermal performance (also known as Lambda value or U-Value). We strongly advise that they always need to look at the aged U-Value to get an accurate figure that is the true reflection of an insulation’s effectiveness over time. Initial U-Value may appear higher but this shouldn’t be the only decision-making criterion. If a roof is measured with a U-Value of 0.2, for example, but the insulation deteriorates over time, then the building’s original energy rating is at risk of being incorrect.

A sustainable choice

This consideration will become increasingly important as green applications and energy ratings become more prominent in building projects. And while we’re on the subject of environmental concerns, the boards are fully recyclable and made using climate-friendly CO2 technology. We find clients asking for these green credentials more and more when developing projects.

Get in touch

If you are interested in learning about our solutions, the technical services we offer, or you are interested in discussing how our systems can be incorporated in a specific project you are working on, please do not hesitate to contact our technical experts. To find out more about our XPS insulation range, please visit our product page.