UK’s ‘most thermally efficient stone wool for cavity walls’ launched

It has been developed using a patented production technology that Rockwool says creates a more efficient fibre structure than traditional stone wool products. The company explained: “With its 0.032 W/m²K thermal conductivity value, users can achieve a U-value of 0.18 W/m²K with a thickness of 150 mm, depending on construction type – 25mm thinner than standard stone wool cavity products within the same wall build-up.

As with all Rockwool stone wool insulation, NyRock Cavity Slab 032 can withstand temperatures of over 1000 °C – achieving the highest Euroclass A1 non-combustible reaction to fire classification – while a high-density semi-rigid composition means it will not slump in the cavity and retains the same thermal and fire resistance properties more than 55 years after installation according to independent research.

The product comes in 455 mm widths to suit standard vertical wall tie spaces, and achieves a closely knitted joint with adjacent slabs, without the need for taping of the joints. This helps eliminate gaps allowing for continuity of insulation across the cavity.

“Energy efficiency is a very real and immediate challenge for the construction sector,” said Paul Barrett, head of Product Management at Rockwool UK. “Alongside the need to improve the thermal effectiveness of existing buildings against a backdrop of rising energy bills, our eyes must also be on the more onerous requirements of the Future Homes Standard, and the UK’s wider 2050 Net Zero Carbon target too.

“NyRock Cavity Slab 032 gives specifiers a new level of thermal performance for stone wool, alongside spacing-saving capabilities, and acoustic and fire performance that are equally critical when providing occupants with comfortable and safe spaces. These performance benefits are also backed by a strong commercial offer, including a competitive price point, and installation efficiencies such as ease of cutting and fitting on site.”