This impressive site contains a 1,000,000 square foot warehouse and a multi-storey staff car park. The main warehouse roof consists of 2 eaves gutters & 14 valley gutters, the roof is also hip ended. The total roof area is approximately 91,950 m2, based on the specified rainfall intensity and geographical location of the project, this equates to a staggering 5,300 litres of rainwater per second falling onto the warehouse roof during peak storm conditions.
Due to the vast amount of water on the warehouse roof and external yard area, your typical surface water underground drainage network would simply not suffice. Therefore, approximately 1.5 Kilometres of Ø2800mm (yes, 2.8-metre diameter pipe!) was installed underground around the full perimeter of the warehouse to cope with the extreme volume of water.
The development consists of the following:
The Siphonic roof drainage consists of primary & secondary systems. On a typical project, the secondary systems would discharge 500mm above external FFL onto hardstanding. On this occasion West Siphonics was asked to run the secondary systems underground alongside the primary systems into the underground drainage network – this was due to the external yard drainage being unable to cope with the potentially high volume of water being discharged onto it. In some cases, the Ø2800mm underground pipework is over 40 metres away from the perimeter of the building. We were able to build this into our Siphonic calculations which meant our pipework could run fully Siphonic all the way out to the discharge point, negating the need for a fall on the pipework as would be necessary with a traditional gravity-fed pipe.
West Siphonics produced 3D Revit models as per the project BIM requirements and attended several coordination/clash detection meetings to ensure our systems were fully co-ordinated with other services prior to our start on site.
In conclusion, West Siphonics are very proud to be a part of this prestigious project. We are happy to report that our site installation teams are progressing well on-site and are on target to hit programme.