Keeping it simple

RA Tech managing director, Russell Armstrong, looks at how some of the complex challenges of our evolving built environment can be met by using simple soluons

here is little doubt that UK buildings are changing. Recent research from Local Authority Building Control (LABC) shows that Britain’s houses are indeed getting smaller [1]. The 2019 Tall Buildings Survey from New London Architecture (NLA) revealed a staggering 541 tall buildings are planned for the capital’s future [2]. While further studies reveal shifting attitudes to renovating and extending.

T Landlocked problem

Whether a specified or chosen heating system utilises a heat interface unit (HIU), unvented cylinder or boiler, building and water regulation requirements call for the safe routing of the relief valve discharge. When dealing with a dwelling some 15 storeys high, or a newly remodelled property with a whole new layout, meeting these regulations can prove particularly complex. Where HIUs, boilers and unvented cylinders are left ‘landlocked’ (cited on internal walls with no clear path to a safe, external discharge point) traditional installation methods for the safe and visible routing of the T/PRV, can prove costly and time-consuming. In fact, the invention of RA Tech’s first hotun dry-trap tundish was sparked by the installation of a landlocked unvented cylinder, where it was necessary to run the pressure relief valve discharge to a macerator. I realised there was no single product available that enabled installers to do that job simply and easily while creating a visible means of discharge to meet regulations and stop foul smells coming back up. This led to the development of our design as a compact, open-sided tundish that incorporates a unique and patented in- built non-return valve, shown below.

For the first time, installers had a single product solution to route discharged water from a relief valve to an internal local drain or waste pipe compliantly allowing both trickle and full flow discharge whilst stopping foul odours back into the building, instead of having to drill through the fabric of the building for an external route or use multiple other products.

Helping at height

The growing popularity of constructing tall multi-occupancy buildings to make greater use of available space creates unique challenges for the installers tasked with designing and implementing the required heating systems and making changes down the line. In high-rise developments such as flats and offices, all boiler and cylinder pressure relief valves could traditionally only be terminated compliantly by being run down the outside of the building, or the internal service voids to basement level, where each would be terminated over an open-trap gulley. This presents a great deal of cost in time, labour and materials for everyone involved in delivering the design of the building, from architect through to the installer. Using a dry-trap tundish within the confines of the dwelling where the appliance is installed and connected to the buildings shared soil stack system provides a simple and easy solution to route the pressure relief valve to drain. Bringing the D1 termination point back inside the dwelling makes the point of discharge visible and accessible, giving building-owners and facilities managers an easy way to check for historical discharges as necessary while also keeping it safe.

When designing waste and soil pipe systems, the suitability of the chosen material for receiving high temperature discharges is an important consideration. Given that boiler discharge rates are significantly lower than unvented cylinders, there may be more material options available for intermittent boiler discharges.

A remedy for remodels

The change to a building’s floorplan following a remodel or refurbishment may leave a HIU, boiler or unvented cylinder situated on an internal wall or in an airing cupboard, inadvertently leaving it ‘landlocked’ with no easy route to take the pressure relief valve to drain outside.

While re-siting the appliance is an option, this can result in extensive re- plumbing which will take time, materials and labour, costs which could make or


break a remodel project. Using a dry- trap tundish offers a simple solution to keeping the appliance in its original location without the need to add service voids to a property or install lengthy runs of pipe through the building to convey the discharge outside. As long as a waste or soil stack is located nearby, in an accessible location, the relief valve discharge can be routed directly to this pipe, ensuring compliance and simplifying the installation.

Lofty ambitions

A national survey recently revealed that 42 per cent of UK homeowners said that extending makes more financial sense than moving [3]. With this in mind, the number of planning applications for loft conversions has reportedly risen by 22 per cent in the last five years [4].

For contractors installing boilers and unvented hot water cylinders in lofts, they are likely to encounter similar challenges to working on a high-rise building. In drilling the external fabric of the building to route the pressure relief valve to outside, the discharge pipe will exit at above first floor level. This requires the contractor to make specific provision for external access via ladders or scaffolding, to enable final connections and for access to diagnose in case of relief valve discharge. In either case, access for installation or maintenance could be both time consuming and expensive. Provided there is an accessible soil stack located near the appliance, bringing the point of discharge back inside via a dry-trap tundish offers installers a convenient, compliant and cost-effective solution which is both safe and visible.

While simplifying installation is a useful benefit to installers, reducing the cost of materials, products and labour pays dividends which are reaped by every party involved in the phases of construction; making dry-trap tundishes a hugely useful product in any building where we work, live or play.

[1] are-britain-s-houses-getting-smaller-new-data/ [2[ 2019/march-2019/london-must-prepare-for- tall-buildings-avalanche

[3] home-insurance/extend-or-move/ [4] using-steel-beams-for-your-loft-conversion/ [5] From the-ultimate-guide-to-building-your-dream- extension-loft-rooms-and-light-filled- basements-fmmcdlbkr

Read the latest at: ‘ When designing

waste and soil pipe systems, the suitability of the chosen material for receiving high temperature discharges is an important consideraon

Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50