Standard Laboratory Tests: How Meaningful are they in Assessing Fire Performance of Insulation Materials?

Summary

A series of large-scale fire tests, using a specially developed fire source and extinguishing technique, were performed to compare the fire behaviour of extruded polystyrene insulation boards in agricultural applications. The boards were specially laminated with aluminium foil on one side.

This was done in order to comply with Scottish Building Regulations which require the wall and roof linings to have a Class 1 (Class 3 minimum) surface spread of flame characteristic (BS 476, Part 7 (1971)) in agricultural buildings exceeding 1130 m³ in volume.

The results show that in the under-purlin mode both lined and unlined material performed similarly but internal temperatures with lined material were higher. In the over-purlin mode the unlined material performed satisfactorily whereas the lined material led to a severe flash over and extensive damage to the building.