Hush Acoustics has helped the developer of an apartment conversion scheme in a Pennine village to achieve superior sound reduction standards in walls and floors that go way beyond the minimum requirements of the Building Regulations.

The Old Mill House project in Diggle near Oldham involved the conversion of a Victorian industrial building into separate residential dwellings. The project’s design had to comply with the requirements of Approved Document E, which sets out minimum standards in England and Wales for airborne and impact sound transmission between dwellings where there is a Material Change of Use.

Keen to deliver the highest quality living accommodation to potential buyers, however, the developer insisted that the acoustic specification not only met the minimum standards but went beyond them. In order to achieve their goals for the floors and walls, they approached Hush Acoustics for assistance in developing the specifications and to provide the required products.

Given the unique nature of the properties being created, the acoustic design for the flooring had to be compatible with underfloor heating and more unusual floor finishes such as stone tiling. This is where the Hush Acoustics team was able to utilise its wealth of experience in different types of floor construction and deploy the most suitable products from its versatile range.

The specification developed by Hush Acoustics for the separating floors beneath the floorcoverings featured a plywood timber deck, below which was the underfloor heating system and 8mm Hush FFR resilient underlay. On the ceiling side, Hush recommended a standard acoustic insulation within the timber joists, two layers of 15mm Fireline plasterboard attached to the underside of the joists, the Hush MF Ceiling System to allow Hush Slab 100 to be fitted in the void created, finished with a layer of 15mm Soundbloc plasterboard.

For the separating walls, two specifications were developed according to the types of wall. In areas where there was an existing masonry wall, a wall lining consisting of independent stud work, Hush Slab insulation and Soundbloc plasterboard was developed. In other areas of the scheme, a twin timber stud wall as recommended, again featuring Hush Slab insulation and Soundbloc plasterboard.

As part of the process, the Hush Acoustics team undertook a number of site visits and provided guidance throughout the design and build process to ensure correct installation was followed, and pre-completion testing was also arranged.

The acoustic solutions developed and provided by Hush Acoustics fully met the developer’s goals to go beyond Approved Document E’s compliance standards.

Pre-completion testing revealed that airborne performances were achieved of 68 dB DnTw+Ctr, 51 dB DnTw+Ctr, 52 dB DnTw+Ctr across the three airborne tests carried out. Approved Document E stipulates a minimum performance level of 43 dB DnTw+Ctr, which means the higher figures delivered by the Hush specifications here represent a significant improvement.

For impact sound, the Hush solution achieved levels of 58 dB LnTw and 53 dB LnTw. Approved Document E sets out a maximum performance level of 64 dB LnTw and anything lower than that figure is improved performance.

A spokesperson for the developer said: “I wanted to create dwellings of the highest quality, and acoustic comfort is absolutely central to that. Partnering with Hush Acoustics on this project was extremely beneficial and I’m delighted with the finished results. The way the team supported me, my architect and contractors from the outset meant everyone involved could be confident that the acoustic products were being deployed in the correct way and that was confirmed in testing.”

Find out more about the acoustic products and fully tested systems available from Hush Acoustics at www.hushacoustics.co.uk.