Erfurt Heatsaver Wall Underliner 2mm x 5m2 Heatsaver is an economical, 2mm thick polystyrene liner containing fire retardants that provide basic insulation as well as combatting condensation and mould growth. To create a more durable and smoother surface we recommend the product is overlined - Wallrock is particularly tough and strong. Recommended adhesive; Good quality ready mixed adhesive suitable for polystyrene veneer. Coverage 5.0m Roll length 10m single Roll width 0.5m Due to geographical locations we are unable to deliver to: Isle of Wight, Isle of Man and Ireland.