ABSTRACT

Introduction The plastics used in the construction industry are generally low-density non-load-bearing materials. Unlike metals, they are not subject to corrosion, but they may be degraded by the action of direct sunlight, with a corresponding reduction in mechanical strength. Many plastics are flammable unless treated; the majority emit noxious fumes in fires. Approximately 20% of plastics produced within the UK are used by the building industry. Polyvinyl chloride (PVC), which has a high embodied energy content, accounts for 40% of this market share, predominantly in pipes, but also in cladding, electrical cable insulation, windows, doors and flooring applications. Foamed plastics for thermal and acoustic insulation are formulated as either open or closed-cell materials, the latter being resistant to the passage of air and water.