Gulf Construction Online - Terrain system copes with heavy rainfall

Pipes

The Siphonic system compared with the traditional gravity system (below).

Terrain system copes with heavy rainfall

01 August 2011

THE Terrain HydroMax Siphonic drainage system offers a complete and proven solution for rapid removal of the high volumes of water deposited in the event of heavy rainfall from the roof areas of today’s increasingly larger buildings.

With 10 times the flow capacity of a conventional gravity system and significantly faster removal rates, the Terrain HydroMax system sucks water from the roof area to cope with the downpours that would overwhelm a gravity system and is ideal for complex roof shapes, says a spokesman for Dubai-based Polypipe Gulf, which has teamed up with Zener Steward, a UAE-based specialist mechanical, electrical and plumbing (MEP) contractor to install these systems in the Gulf region.

“Offering valuable total project cost savings of typically 20 to 45 per cent over a conventional system, Terrain HydroMax can provide important structural and space savings, also leading to a reduced build programme,” the spokesman adds.

Elaborating on how the system works, the spokesman says: “The Terrain HydroMax sucks water from the roof, using a powerful hydraulic force created by water accelerating down the full height of the building to deliver far greater capacity and flow rates than a gravity system.

“In a gravity drainage system, the pipework carries both air and water. The flow in gravity pipes is extremely inefficient because of the large core of air that enables the water to flow, resulting in the need for larger pipes and more of them as well as extensive underground systems.

“In the Terrain HydroMax system, as rain falls, the roof drain prevents the ingress of air, rapidly purging it until the system is fully primed and running full bore. Water is transported in smaller diameter pipes to fewer, more convenient locations. The system responds quickly to rainfall changes, is self-cleaning, drains rapidly when rainfall ceases, and is designed to prevent blockage by leaves, twigs and other debris.”

Citing some of the benefits of the Terrain HydroMax, he says the system shortens the construction build programme and significantly reduces below-ground drainage pipe diameters, trenching and backfilling work, whilst the small bore pipework places less load on the structure. Overall, the system requires fewer roof penetrations and internal downpipes. Less space is taken up by pipework, and with fewer collector pipes to convey water to the perimeter of the building or other preferred locations, such as a rainwater harvesting tank, much valuable and usable space is released.

The high level carrier pipes are installed horizontally without gradient, and pipes can be zoned beneath the roof along with air, electricity, water and other services. There is no need for drainage below the floor slab and no restrictions on downpipe location.

The system offers a comprehensive range of roof drains for every flat and pitched roof membrane, from asphalt to bitumen to modern single-ply membranes.

It is recommended for use with HDPE (high-density polyethylene) pipes. Controlled, prefabricated manufacturing of the HDPE piping system reduces site work, with less on-site welding and cutting required. “This method minimises changes to layout during installation. Terrain HydroMax is ideal for commercial, industrial, sports, leisure, education and healthcare buildings; the roof drains are extremely compact and the range includes an inlet for the top deck of multi-storey car-parks,” he says.

The system is available in the region as a complete design-and-install package through Zener Steward to ensure an effective solution is achieved, says James Simpson, general manager for Zener Steward, a specialist approved installer which has offices in the UAE and Oman and is soon to open one in Qatar.

“The system’s to simplicity and cost effectiveness is already proving beneficial to major developments across the region, addressing a recognised issue to manage rainwater more efficiently,” he says.

Zener Steward is owned by the Zener Group and Stefanutti Stocks. The Zener Group of Companies, formed in 1974, spans a number of complementary industrial activities including electrical and electronics services communications, electromechanical, marine electronics, safety and security, fire fighting, fire protection, and audio and visual.

With more than 1,000 permanent staff, the company has been responsible for many of the major projects in the Gulf and has a bluechip client list including Emirates Telecommunications Corporations, Dubai Police, the Defence Ministry and The Engineers Office.

Polypipe Gulf, part of the UK-based Polypipe, offers a unique combination of above- and below-ground drainage, hot and cold water, heating, ventilation and water management solutions, suitable for commercial buildings such as hospitals, hotels, sports stadiums, retail complexes and offices, as well as residential apartments and villa developments.