Recticel Powerdeck U

Recticel Powerdeck U is one of the most widely specified rigid PIR insulation boards for warm flat roof construction in the UK, trusted by roofing contractors, builders and specifiers on both new build and refurbishment projects. Designed specifically for use with bituminous torch-on felt waterproofing systems, it combines high thermal performance, outstanding compressive strength and excellent dimensional stability to deliver a reliable and flat substrate for the waterproofing layer above.

What is Recticel Powerdeck U?

Powerdeck U is a rigid polyisocyanurate (PIR) insulation board with a PIR foam core faced on both sides with a bituminous glass fleece. This specialist facing is what sets Powerdeck U apart from standard PIR boards — it is specifically engineered for compatibility with torch-on felt systems, where the bituminous facing assists adhesion between the insulation board and the waterproofing membrane applied above it. This makes for a cleaner, faster and more reliable installation compared to standard foil-faced PIR boards, which are not suitable for direct torch-on applications.

Thermal Performance

Powerdeck U offers a thermal conductivity of between 0.024 and 0.026 W/mK depending on thickness, making it a high-performance PIR solution for achieving the required U-values in warm flat roof build-ups. Warm flat roof specifications typically target a U-value of 0.18 W/m²K for new build domestic roofs in England and Wales, and Powerdeck U is available across a range of thicknesses to meet or exceed this requirement depending on the full build-up. All boards measure 1200 x 600mm, making them easy to handle and manoeuvre on site.

Compressive Strength & Stability

With a compressive strength exceeding 150 kPa, Powerdeck U offers the structural integrity needed to support light foot traffic during installation and to resist the forces exerted by the waterproofing system above. Its excellent dimensional stability ensures boards remain flat and true throughout the installation process, helping to create the flat, consistent substrate that a high-quality torch-on felt finish demands. Precision-cut dimensions mean boards fit together cleanly, reducing the risk of gaps or unevenness in the insulation layer.

Applications

Recticel Powerdeck U is suitable for use in warm flat roof construction on timber, concrete and steel decks, for both new build and refurbishment projects. It must be used in conjunction with a vapour control layer below and a compatible bituminous torch-on felt waterproofing system above, and can be installed in mechanically fixed or adhesively bonded build-ups.

Sustainability

Powerdeck U is manufactured using a blowing agent with zero ozone depletion potential (ODP) and low global warming potential (GWP). The PIR foam core does not degrade or deteriorate when exposed to moisture, meaning it will not lose thermal performance over time — an important consideration in flat roof applications where the risk of moisture ingress is higher than in other applications.

Why Buy Recticel Powerdeck U from Insulation UK?

At Insulation UK we stock a range of the most popular Powerdeck U thicknesses for immediate despatch, with free delivery on orders over £500 ex VAT. Our technical team has over 50 years of combined experience in the construction industry and can help confirm the right thickness for your project build-up — call us on 03003 034 578 or email sales@insulationuk.co.uk. If you need a thickness that is not shown in our stocked range, please get in touch and we will advise on lead times and availability.

Always refer to the latest Recticel Powerdeck U technical datasheet, Declaration of Performance and BBA certificate before specification or installation.