125 underlay is intended for use in bituminous built-up roofing systems. Can be used with any underslating materials, including breather membranes, any tile or slate finishes and in cold or warm roof configurations.
Polyester based underlay coated with bitumen and surfaced with fine sand.
125 Underlay conforms to BS747 type 5U.
125 Underlay will ensure long term performance of the underslating, preventing water from running behind the gutter, rotting timber fascias and rafter ends
