BRE IP13/04 PDF

Introduction

SIPs are prefabricated lightweight building units, employed, in most cases, as principal loadbearing components. They are currently used in domestic and light industrial construction of up to three storeys in height. This construction method is increasingly common in the building industry and in the UK about 3000 homes have been constructed with SIPs since the 1980s.

In Europe SIPs are mainly used as loadbearing internal and external walls and sometimes roofs, whereas in the USA, from where these composite systems originate, they are also frequently employed as floors and roofs.

A SIP consists of two high density face layers which are bonded on both sides of a low density, cellular core substrate (Figure 1). A strong, structural bond between the three layers is essential to the loadbearing ability of the SIP so that high loads can be transmitted by the relatively light units without using internal studding.

SIPs should be not be confused with cladding sandwich panels, which are similar in their manufacture but different in their use. In Europe cladding sandwich panels are common in the food processing and cold storage industry, where they are used to clad structural steel or concrete frames[1]. Cladding sandwich panels use different board materials to SIPs and are normally manufactured in larger sizes. The most significant difference is that cladding sandwich panels, in contrast to SIPs, only allow the transmission of moderate wind and snow loads to a loadbearing frame or structure. SIP walls can bear considerable vertical and horizontal loads without internal studding.

Although SIPs are currently mostly used in buildings of up to three storeys in height, their vertical loadbearing capacity and consistent thermal performance offers great potential for higher rise construction.