Universal Non Breathable underlay is a 140g/m2 membrane that comes packed full of features and benefits designed to promote consistent installation to the British Standard. Marley Eternit Universal Non Breathable underlay is a high performance, impermeable roof membrane for use in a range of pitched roof constructions, where traditional ventilation methods are preferred. Complete with an integrated tape system, this underlay provides and effective wind barrier, with unrestricted usage across all UK wind zones (BS 5534). A three-layer composite comprising of two spunbonded polypropylene fabrics - with a non-breathable polyolefin film - provides an ultra strong, durable and easy-to-install under-tile layer that is suitable for warm or cold roof applications. Advantages Integrated tape system for sealing underlay laps. Creates an impervious barrier with superb wind-uplift resistance. No need to increase laps to coincide with tile batten courses, minimising cost. No need to use an additional fly batten to secure laps. Printed guidance lines Provide a visual reference to ensure sufficient lap to the British Standard. Ensure that the underlay is laid consistently and straight. Universal Non Breathable underlay integrates seamlessly as part of a comprehensive Marley Eternit roof system, or with other manufacturers tiles and slates.