Building Regulations Exceeded with Modern Polyurethane Technology
By Leonie Onslow-Dewey
As part of its Climate Change programme the Government continues to increase thermal insulation requirements within Building Regulations. Indeed, the latest revision in 2006 has led to a situation where buildings built just a few years ago – i.e. to 2002 Regulations – fall considerably below current standards.
In order to address this problem, specifiers are following the Continental trend and utilising modern polyurethane technology to achieve or exceed Building Regulations, as the depth of foam is increased to meet the required insulation values. Applied as a liquid to roofs – as well as to walls and ground floors – it expands to create a superior insulation and acoustic barrier.
The British Urethane Foam Contractors Association (BUFCA), the trade association for the polyurethane foam contracting industry, stresses that when specifiers are looking for the potential for further savings in carbon dioxide emissions and energy conservation, they should recognise that spray-applied polyurethane foam (SPF) has the properties to meet the exacting criteria.
For existing dwellings sprayed foam systems can be applied to various depths and have a K value of 0.02W/mK. When sprayed to a depth of 85 mm the U-value of a typical roof with 100 mm fibreglass at ceiling level is reduced from 0.34W/m2K to 0.16W/m2K, surpassing current Building Regulations.
The polyurethane (PU) two component liquid system produces a highly efficient blanket of insulation, with a thermal conductivity approximately twice as efficient as fibreglass. It is particularly cost-effective and easy to apply to a wide variety of substrates. Its closed-cell nature renders it very resistant to moisture ingress, and grades are available which achieve both Class 1 and Class 0 fire ratings when tested to BS 476 part 7 and 6 respectively. The urethane foam can be applied in any thickness to suit the insulation requirement of the building.
One of the major benefits of spray-applied polyurethane foam is its ability to produce a seamless blanket of insulation, which is joint free, bonding strongly to most building materials. Otherwise jointed systems give rise to a potentially weak point, leading to a significant loss of insulation value.
Where applicable all systems are installed to a British Standard Code of Practice, with Renotherm operating to Agrément Certification: an insurance-backed guarantee is available.
Literature on the use of sprayed polyurethane for walls, lofts and other applications is available from Renotherm Ltd by contacting us
