The construction industry has used Structural Insulated Panels for years, but it's now filtering into the self-build market too
Most involve some degree of off-site manufacture including Structural Insulated Panels (SIPs), and lead to a reduction in the amount of time on site.
These offer a speedy construction plus strength and high levels of insulation. They are prefabricated panels of OSB (oriented strand board) that form a sandwich with a filling of insulation. Window shapes can be cut out to order off-site and the panels can be used for floor and roof as well to form a monolithic structure.
Once erected, work can begin straightaway on internal fitting out even before the exterior is complete. As well as speed, their best asset is insulation. Enviropanel, one of the manufacturers of SIPs, reckons their use can reduce running costs by up to 60 per cent. Another benefit is the creation of additional warm living space in the roof by eliminating conventional trusses. The large size of the panels also makes them less prone to pilfering on site.
This method of construction was introduced into the U.K. in the 1970’s. However, several factors, including more stringent Building Regulations aiming for lower U-Values, new government reports calling for improvements in quality, efficiency, and environmental awareness in the building industry and a shortage of traditional building skills have led to the recent rapid growth in the popularity of SIPs.
Structural Insulated Panels form part of a pre-engineered building system, manufactured off-site in a strictly controlled environment and then transported in a suitable format for on-site installation in the most efficient way.
SIPs panels are manufactured in a one step process by injecting CFC free Polyurethane foam (PUR) in between two skins of Oriented Strand Board (OSB3) in a hydraulic press. The resultant panel is lightweight but incredibly strong. The skins are autohesively bonded during manufacture and the structural composition can be compared to that of an I-Beam.
Structural Insulated Panels can form the structural shell of a building, which can then be finished with conventional materials, or they can be used as an insulated envelope over an Oak Frame structure, or indeed as infill panels to steel or timber structures.
The versatility of this product enables it to be used for the construction of houses, apartments, schools, offices and extensions. SIPs can be used to form a warm roof over a conventionally constructed building to create additional living area. Other applications include the creation of a structure inside the brick shell of an existing building (e.g. barn conversions), to take advantage of the unique thermal qualities of SIPs.
Image: Hemsec Sips