The waterproofing material par excellence of modern construction. Overcoming the limits of old hot-applied tar, the prefabricated ardesia sheet guarantees constant thickness, a tear-resistant reinforcement and an integrated aesthetic through the protective mineral layer.
Pure distilled bitumen is temperature-sensitive. The APP (Atactic Polypropylene) mix offers high heat resistance (up to 150°C), ideal for Mediterranean climates. The SBS (Styrene Butadiene Styrene) mix gives the bitumen elastomeric behaviour, similar to rubber, guaranteeing exceptional cold flexibility (down to -20°C), ideal for alpine climates or metal structures subject to thermal expansion.
UV radiation destroys polymer chains causing premature ageing (alligatoring). For exposed flat roofs, the sheet is produced with a top ardesia or mineral granule self-protection. This layer totally shields UV rays, extending roof life by over 50%, and allows chromatic integration (e.g. red ardesia in historic centres or white to reflect solar heat).
Standards
European and international references applicable.
Physical properties
Usage environment
Torch application on timber roofs requires extreme care: prolonged flame use can ignite latent fires in the underlying decking. Today self-adhesive versions activated by solar heat are available for high fire-risk sites. Always use a double-layer system (smooth 3 mm base + ardesia 4.5 kg/m² finish) with staggered joints.