Meeting the challenge of Rain Noise in Schools – BB93

Contractors working on the Priority Schools Building Programme are facing a new challenge – performance standards for rain noise. With the advent of the new BB93 Section 1, rain noise will be a challenge for all school projects.

Ever since they began building schools with lightweight materials, contractors have had to consider rain noise. However, they haven’t had to meet specific standards until recently. Although the 2003 edition of the Government’s Building Bulletin 93 (BB93 – Section 1) stated that rain noise was important in school design, a specific UK performance standard for rain noise was only introduced as part of the Priority Schools Building Programme (PSBP) in 2012.

This spring a consultation began which will mean that Section 1 of BB93 will be replaced with the PSBP standards. By the end of 2014, all contractors working on schools will therefore need to meet rain noise performance standards.

Why Acoustics in Schools is Important

Good acoustic conditions are extremely important in schools. Students need to hear the teacher, and be able to speak to each other, clearly and without interruption. Noise should not interfere with their study activities. If every time it rains the class is unable to concentrate or hear the teacher, or exams are disrupted, the school is no longer serving its primary purpose.

Part E of the Building Regulations (2010) therefore states that:

“Each room or other space in a school building shall be designed and constructed in such a way that it has the acoustic conditions and the insulation against disturbance by noise appropriate to its intended use.”

This element of the building regulations was deemed to have been satisfied by complying with BB93 Section 1, which did not require a specific performance standard for rain noise – instead it was sufficient to have “demonstrated to the Building Control Body that the roof has been designed to minimise rain noise.” [BB92 Section 1 Page 10]

However, the government intended to introduce a performance standard for rain noise, and they have initially introduced it via the Priority Schools Building Programme.

The challenge to contractors

Framework Contractors and their architects working on the Priority Schools Building Programme currently need to ensure that the roof build-ups they use achieve ambient rain noise levels set out in the DfE document ‘Acoustic Performance Standards for the Priority Schools Building Programme’.

Each new or refurbished school needs an individual acoustic report, and each room in the school must comply with acoustic performance standards. This can be a challenge for designers who need to develop roofing specifications that meet the requirements in a cost effective way.

If contractors seek to use a variety of manufacturers to meet the standards, they have to cover the cost of testing each proposed build up to get it certificated. With more than one supplier they also run the risk of substituted products, buildability issues, inexperienced roofing contractors and ultimately an invalidated warrantee.

Accepting The Challenge

At SIG Design and Technology, we identified the need within our contractor clients and their architects for a solution to school roofing that would enable them to meet the new performance standards in a practical way, mitigating the risk of their clients now more exacting requirements.

SIGD&T provide a deck-up roofing design, supply, installation and guarantee service, made possible because we are not product manufacturers but suppliers, part of SIG Plc, a leading distributor of specialist building products in Europe.

We are therefore in a unique position to assist contractors in meeting the new acoustic performance standards reliably and cost effectively, as we have all the expertise, materials and design knowledge in house:

1. The insulation expertise of our partners at SIG Insulation;
2. Access to acoustic consultancy expertise and bespoke products in house, and
3. The 8-step deck-up design, installation and guarantee service of SIG Design & Technology.

With this in mind, we have been working with our colleagues across SIG Plc to develop a complete solution with one point of contact, a full system warrantee and design responsibility.

8 Roof Build-ups, A one-stop certified solution

Working with our contractor customers, a set of eight roof build-ups have been developed using a range of products sourced within the group, including waterproofing, vapour control, acoustic matting and other insulation.

Earlier this year a set of independent tests on each of the build-ups were carried out by external laboratories. Each sample build-up was constructed as a roof at the testing laboratories in Suffolk and tested using a rain test rig.

The rain test rig simulates rain using a specially contracted tank from which rain droplets form through holes in a polycarbonate plate. Sound pressure levels are then measured in the room. The entire procedure was carried out according to BS EN ISO 140-18.

The build-ups, which include a value-engineered option, provide an A-weighted sound intensity (LIA) of between 40 and 58.6 dB in independent tests. These figures are certified and enable our contractor and architect clients to choose and use our roofing build-ups with confidence.

Performance Standards for Rain Noise – in All Schools Projects

To date, SIG plc remains one of the few companies who have tested their specification to PSBP/BB93 standards, and alongside the comprehensive range of options tested, we are in a unique position to offer certified, fully guaranteed roofing solutions to schools in the Priority Schools Building Programme.

As a result of this unique offer SIG D&T are delivering a full system roof design to five schools in the West Midlands, three of which have already been completed. The system is being rolled out across the country with schools in the northwest and London currently being negotiated.

Later this year, it is expected that the standards we have been applying in these projects will be requirement for all schools work.

In BB93 Section 1 (2003) the government stated their aim to introduce a performance standard for rain noise in the next edition of the building bulletin, and earlier this year the new BB93 went out to consultation with the requirement that the acoustic standards of the Priority Schools Building Programme would be incorporated. When BB93 is implemented, probably later this year, it will mean that all work to schools will need to apply specific performance standards for rain noise to roofs.

If you’d like to find out more about our certified roof build-ups or discuss your schools projects, please get in touch via our contact page, or contact me via Linkedin.