Siphonic for Amazon Project in Southwest England

Amazon Project

  • Client
  • Architect
    UMC Architects
  • Contractor
    TSL Projects
  • Location
    Southwest England
  • Technology
  • Scope
    Design, Pre-fabrication, Installation

An End to End Solution

TSL Projects engaged Capcon Engineering to design, supply, prefabricate and install a highly efficient roof drainage system for a 10,000m² data centre for their client, Amazon. The building in Southwest England has a large, double-pitched roof, typical of data centres and logistics facilities.

A traditional gravity drainage system could have been proposed for the large building and would have worked adequately. However, our expert rainwater drainage designers determined that siphonic drainage would be the most efficient and effective rainwater roof drainage solution.

Capcon’s design team determined the two eaves’ gullies would require four siphonic drainage systems, which would terminate in strategic locations to suit the on-site civils requirements. In the final design, only 14 outlets and 367m of fully welded HDPE pipework, capable of draining 590 litres / second, were required to drain the 10,000m2 building.

Siphonic Solution Reduces Costs And Raw Materials

Had a traditional gravity approach been pursued a number of factors would have increased costs. Firstly over 500m of gravity pipework would be required to drain the building, not to mention the additional civils pipework. The pipe diameter would have doubled to facilitate a gravity flow where only 30% of the pipe is utilised. All this extra pipework and pipe diameter would have increased raw materials by over 2.5 tonnes and lead to longer installation times.
Traditional GravitySiphonic SolutionSiphonic Saving
Pipework (Metres)50036727%
Raw Materials (Tonnes)41.562%
Install (Days)171230%


Our team of experienced technicians installed all siphonic systems safely and efficiently on-site, in line with the rapid programme requirements for this project.


  • 367m of Pipework
    367m pipework designed, prefabricated, and installed on this project
  • 14 Outlets
    14 outlets acrosss 10,000m² of roof
  • 4
    4 Siphonic Systems
    Designed, pre-fabricated, installed, air-tested and commissioned
  • 590 litres / second
    Capability of draining 10,000m² building at 590 litres/second

Stock photography of Capcon technicians tightening siphonic brackets.