The redevelopment of the almost derelict Drill Hall in the Old Market area of Bristol to 40 prestigious inner-city homes has included the use of OSMA SiTech from Wavin Plastics – the UK’s leading provider of water management solutions. A low noise, push-fit soil system, this product offers the ideal solution for effective sound-reduction in flats and apartments.

Sion Developments, the company behind the project, opted for SiTech to minimise the transference of noise of daily flushings which can otherwise travel to adjacent room space.

“Previously, the answer to this problem has been to simply to wrap soil stacks in mineral wool and enclose them in a duct,” said Karly Taylor, spokesperson for Wavin Plastics. “Compared with other options, this kept costs relatively low, but acoustic effectiveness was equally modest. For many architects, cast iron has been the favoured method of achieving better results – but at a price.

“SiTech offers an effective alternative to cast iron. It delivers all the required acoustic suppression performance whilst being lightweight and easy to install due to the push-fit fittings. SiTech is both a practical and affordable solution for the installer.”

SiTech is made from minerally reinforced polypropylene (Astolan®), which is able to absorb airborne sound as well as structure borne sound. The 110mm pipe and fittings provide sound-dampening acoustic properties in internal soil installations. SiTech has the effect of increasing pipe density, which means that it only needs to be encased in 25mm mineral wool wrap where contact between the pipe and the building structure cannot be avoided. Therefore, it cuts down on installation time, wrapping and tooling costs and can be installed by professional plumbers rather than specialist fitters that are often required for cast iron and HDPE systems.


OSMA Si-Tech has been independently tested for sound reducing performance and exceeds DIN 4109 requirements (less than or equal to 30db at two litres per second flow in a noise protected room) and helps to achieve the higher acoustic performance standards as required by the Building Regulations Part E 2003. The system holds a LABC system type approval certificate.

“Part E 2003 of the Building Regulations was introduced to deal with the problem of noise and to improve the resistance of structures to the passage of transmitted sound – even more important when people live in close proximity to one another,” adds Karly. “The regulations demand the walls and floors in dwellings and rooms used for residential purposes have reasonable resistance to sound and that shared areas of flats or rooms are constructed to prevent excessive noise levels.

“Drill Hall is a great example of where SiTech can be put to best use. It can be used for vertical soil stacks and horizontal WC pipes and is faster and easier to install than more traditional systems. It’s especially suited for high density buildings which require noise control such as apartments and hotels as well as museums, schools, hospitals, care homes, judicial courts and libraries. There has been a definite shift towards high-rise flats as we struggle to accommodate a growing population – and with that comes a need for tall soil stacks. Wavin’s research and development centre created SiTech to address this issue while also keeping noise to a minimum so people in adjacent rooms don’t have to hear other people’s drainage. Who wants to live or even just spend time in an environment where you’re constantly reminded of the fact that waste water is rushing by?”

According to the book ‘Old Market, Newton Lawrence Hills and Moorfields’ by local historians David Stephenson, Andy Jones, David Cheesley and Ernie Haste, the Drill Hall first opened on 5 June 1915 as the home of the 4th Battalion Gloucester Regiment. During the Second World War, members of the American Army were stationed there, including world boxing champion, Joe Louis.

In the 1970’s the building became a post office sorting depot and stayed that way until the 1990’s. It remained unused after that, until Bath-based Sion Developments started work to transform the building into homes.

“Buildings such as Drill Hall, which are now being redeveloped, need noise eliminating products which are future proof so they’re still as effective in 50 year times as they are today,” adds Karly. “Wavin is committed to providing innovative – and lasting – solutions to customers and not just products with a short life span. We work closely with professional plumbers to make sure we create solutions which solve problems that they come across in their day-to-day work.

“We know from research we conducted earlier this year that the majority of plumbers feel they have a responsibility to use sustainable products and advise their customers to do so, but of course, it often comes down to price. It’s been great to see that attitudes towards sustainable products are shifting as more and more installers become aware of the whole life cost of buildings and the need to install sustainable products at the outset. And it’s not just one stage of the water cycle that needs sustainable products, but every stage.

Karly concludes: ‘Every stage of the water cycle interlocks from the minute it rains to the minute you flush a toilet but overall sustainability of the whole cycle can only be achieved if each of the products within that cycle offer sustainable benefits. We aim to provide solutions that meet the needs not only of that specific function, for example, minimising or eliminating noise during the removal of waste water but which also contribute to the overall sustainability of the whole clean and waste cycle.”

Email: steve@watermarkpr.co.uk