Noise issues inside buildings resulting from poor acoustic performance of the roof can be resolved using the Hush FR Roofing Membrane from leading UK acoustic products manufacturer, Hush Acoustics.

Principally designed as an additional acoustic layer for lightweight flat roof systems, the product’s performance capabilities mean it may also provide an effective solution for other types of roofs too, including metal systems such as standing seam. This is due to Hush FR’s composition of recycled rubber crumb bonded with polyurethane to form a 10mm membrane, which greatly increases mass in the roof construction and reduces vibration caused by raindrops hitting the external roof surface.

Hush FR Roofing Membrane has been subjected to extensive testing at a UKAS accredited facility to confirm its performance in flat roof systems for both airborne and impact sound insulation. In all the tests conducted, an improvement in the acoustic performance of the roof construction was recorded compared to designs that did not feature the membrane, with some of the performance levels being significantly higher.

Robert Crampton, Managing Director of Hush Acoustics said: “When designing, specifying and installing a flat roof solution, mitigating the risks of airborne and rain impact noise are two considerations that should be placed high on the agenda. This is especially so for education and health sector buildings where indoor acoustic comfort is of particular importance and governed by sector-specific guidance.”

“By undertaking comprehensive testing for Hush FR Roofing Membrane, we’ve been able to demonstrate its capabilities for accommodating both airborne and rain impact noise performance requirements in lightweight flat roof constructions, whilst also delivering significant benefits in terms of thermal insulation and project costs.”

The performance provided by Hush FR Roofing Membrane enables flat roof designs to achieve the minimum acoustic standards in school buildings, set out in Building Bulletin 93 (BB93): acoustic design of schools - performance standards. This guidance document was developed in acknowledgement of the potential for poor acoustics in learning environments to negatively impact on children’s education and their personal development.

BB93 specifically addresses acoustic performance in roofs. It requires that lightweight roofs and roof glazing are designed “to provide suitable control of rain noise reverberant sound pressure level in a space”, and that “levels during heavy rain should not be more than 25 dB above the appropriate indoor ambient noise level.”

Hush FR Roofing Membrane is also suitable for flat roofs on buildings designed for use as hospitals or health and social care facilities. In England, these must be built in accordance with NHS England’s Health Technical Memoranda (HTM) 08-01.

Like BB93, HTM 08-01 addresses the potential for excessive noise to damage our health and wellbeing. It recognises that “acoustic design is fundamental to the quality of healthcare buildings” and acknowledges how unwanted sound affects us both physiologically and psychologically. Its checklist specifically states that noise-sensitive accommodation should be under a roof that “will adequately control rain noise”.

Assessment of the product’s airborne sound performance involved testing five different roof constructions – three with and two without the Hush FR Membrane – in accordance with BS EN ISO 140-3:1995. The tests for impact acoustic performance in various flat roof constructions generated by rainfall were conducted in accordance with BS EN ISO 140-18:2006. In addition, further predictions of the change in airborne sound insulation and rain noise intensity levels were undertaken by engineering and design consultants WSP Group based on the incorporation of several different metal frame ceiling systems.

Hush FR Roofing Membrane is supplied in 6m rolls with a width of 1250mm. It is manufactured to a density of approximately 770 kg/m3 and it is conditionally resistant to acids and bases, as well as being rot-proof and water resistant.

Find out more about Hush FR Roofing Membrane at www.hushacoustics.co.uk or call 0114 352 0695 for technical guidance on how to achieve acoustic performance targets in a roof design