The Chesterfelt Deflector SBS Torch On Roof Underlay is a torch-applied roofing membrane designed for use in multi-layer built-up roofing systems. It measures 8 meters in length and 1 meter in width, making it suitable for large surface coverage. Manufactured with SBS (Styrene-Butadiene-Styrene) modified bitumen, it offers enhanced flexibility and durability, especially in varying weather conditions.

This underlay typically features a sanded or mineral-finished upper surface and a thermofusible film on the underside, allowing for secure adhesion when applied with a gas torch. It is commonly used as an intermediate layer between a venting base sheet and a capsheet, contributing to the overall waterproofing and structural integrity of flat or low-pitch roofs. Its robust construction helps resist punctures and accommodates foot traffic during installation and maintenance.