A ventilated pitched roof with a bituminous membrane combines a continuous thermal insulation layer with a ventilated cavity beneath the upper roof covering.
The ventilation space allows air to circulate along the roof slope, typically from the eaves towards the ridge. This airflow helps dissipate part of the heat accumulated beneath the roof covering during warm periods and can assist in the drying of incidental moisture.
POLIISO® SB is a rigid closed-cell polyisocyanurate (PIR) insulation panel particularly suitable for this type of roof construction. The panel features an upper bituminised glass-fibre facing and a lower saturated mineralised glass-fibre facing, providing a surface specifically designed for integration with compatible bituminous roofing systems.
POLIISO® SB provides a declared thermal conductivity λD from 0.025 to 0.028 W/mK depending on thickness, a compressive strength of ≥ 150 kPa and a maximum operating temperature of 110°C.
The combination of PIR thermal insulation, a compatible bituminous membrane and a correctly designed ventilation cavity creates an effective solution for both new and renovated pitched roofs.
