Fast-growing Scottish timber-frame specialist, Custom Homes, is expecting to increase its use of Norbord’s Sterling OSB sheathing board as it gears up to meet the demand for Structurally Insulated Panels (SIPS).

A long-standing supplier of specialist designs and materials to the self-build sector, Custom Homes joined forces with SIPS pioneer, Jim Miller, in 2006 to develop SIPS panels for a variety of customers. The company is now manufacturing its own SIPS, called Eco Panels, for larger-scale residential and non-residential projects. Jim is now Managing Director (Manufacturing) at Custom Homes.

Last year, Custom Homes Eco Panels built over 150 residential units and this year that figure is set to increase by at least 50%. The company has recently completed a development of 14 town houses in Plymouth as well as undertaking a number of non-residential projects, including large new premises for a prestigious Hertfordshire client, now nearing completion.

Jim developed the insulated panel concept in partnership with Napier University, resulting in Custom Homes Eco Panels using OSB sheets to create a strong, lightweight sandwich panel with an expanded polystyrene core. “Norbord has been our sole supplier of OSB from day one,” says Jim.

Eco Panels comprises of slabs of thermally-efficient expanded polystyrene insulation sandwiched between two sheets of 11mm thick Sterling OSB3, a grade of OSB recommended for humid environments. The combination of the lightweight insulation and the rigid outer skins produces a very strong structural panel capable of going up five floors which not only has excellent thermal properties but is also very light in weight.

The finished panels vary in total thickness from 119mm to 194mm and are produced in two standard sizes: 1200mm x 2400mm and 1200mm x 4800mm. “We started out using the largest boards available in the UK - 2400mm x 4800mm,” says Jim “but these made panels difficult to handle on site.”

The longer (4800mm) SIPS panels are generally used for pitched roof applications, allowing rooms to be built in the roof, while the shorter 2400 panels are used for walls. “We aim to keep a stock of standard panels so we can supply at short notice,” says Jim, who adds that up to 95% of bespoke house designs can be realised using standard-format SIPS panels.

“The OSB board is of primary concern in the performance of SIPS panels,” says Jim. “It is what gives the panel its strength. Norbord always supplies good quality, accurately-sized boards,” he adds.

With its factories in Glenrothes, head office in Sudbury, Suffolk and regional offices throughout the country Custom Homes covers the whole of the UK and despite the current economic crisis, has a growing order book. “We currently consume a few lorry loads of Sterling OSB per month, but that is set to increase this year,” comments Jim, “we’re getting busier all the time”.