Specification

Polyfoam XPS has seen increased interest in the use of extruded polystyrene (XPS) in masonry cavity walls below damp proof course (DPC) level. The use of XPS in this way is a relatively new development, aiming to maintain an existing insulation specification above DPC level, but take advantage of XPS’s moisture resistance in a location … Read more

Thermal insulation materials used in cavity walls “should be the subject of current certification from an appropriate body”, as per Approved Document C in England. Cavity wall solutions typically feature a single product type throughout the whole wall construction. Because that product continues below DPC, it may seem as though the requirement for third-party certification … Read more

External walls below DPC require specific detailing. The junction of the wall with the ground floor construction must achieve continuity of insulation to meet the energy efficiency requirements of national building regulations, such as Part L 2021. At the same time, the choice of insulation solution must not compromise the building’s ability to resist moisture. … Read more