Truss manufacturer Donaldson Timber Engineering says its Structural Insulated Roofing System (SIRS) is proving its benefits in partnership with Dalkeith-based Opal Homes at its sites in Anstruther, Fife and Heriot in the Scottish Borders.

At Anstruther, SIRS has enabled Opal to erect three roofs and six dormer windows in a single day. At Heriot, an Opal development of seven traditionally styled properties with heavy slate roofs, SIRS is claimed to have proved that a modern construction method could be used to create a vernacular roof more efficiently.

SIRS incorporates Structural Insulated Panel technology – rigid polyurethane sandwiched between two sheets of OSB – and is used as a roofing system and for cassette floors, excluding the use of purlins.