Isocheck Quietroof system, supplied by Isomass Ltd. Unit 14 Papworth Business Park, Stirling Way, Papworth Everard, Cambridgeshire CB23 3GY and installed in accordance with manufacturer’s instructions / recommendations.
Full installation instructions for Isocheck Quietroof is available as a pdf to download. Go to the Downloads tab on this page.
Problems of noise from rain on metal roof cladding
The noise of raindrops falling on a metal roof, especially during heavy rain, is incomparably bigger than rain falling on concrete or clay tiles. This noise spreads throughout the unflanked roof construction and into adjacent buildings - disturbing the occupants inside the rooms. Particularly problematic are noisy activities in closed metal constructions, where sound intensity amplifies significantly - caused by poor sound absorption capability of metal sheets, which also creates echo.
Regulations for various facilities, including schools and hospitals, require that suitable control of rain noise reverberant sound pressure levels have been addressed within the design of the building. For hospitals, ‘Health Technical Memorandum 08-01: Acoustics’, requires: “indoor ambient-noise levels during ‘heavy’ rainfall, as described in BS EN ISO 140-18, should not exceed the intrusive noise criteria by more than 20dB, or should not be more than 65dB, whichever is lower.”
In schools, ‘Acoustic design of schools: performance standards Building Bulletin 93 2015’ requires that: “Building Regulation submissions should demonstrate that lightweight roofs and roof glazing have been designed to provide suitable control of rain noise reverberant sound pressure level in a space (calculated using laboratory test data with ‘heavy’ rain noise excitation as defined in BS EN ISO 140-18). Levels during heavy rain should not be more than 25dB above the appropriate indoor ambient noise level given in table 1”, which for classrooms and general areas of Nursery, Primary and Secondary Schools is 35dB.
Traditional soft insulation such as mineral wool may dampen vibrations in the panel but could provide thermal bridging to other components. Rigid insulation will provide excellent thermal performance but its acoustic value is low and it may also have the same bridging effect. What is required is a solution which eliminates bridging and improves acoustic insulation.