Syphonic Drainage: How Does It Work?

One of the biggest problems many roof drainage systems fail to accommodate is the unexpected build-up of large amounts of water. Without an adequate drainage system able to cope with occasional periods of heavy rainfall your roof can become waterlogged or even severely damaged within a very short period of time.

Traditional drainage systems tend to operate inefficiently during heavy rain, which is why at Roofing Consultants we recommend the installation of a syphonic drainage system.

Sadly in the early 1990s there were several scare stories regarding the efficacy of syphonic drainage systems, as a number of high-profile syphonic failures caused many to lose confidence in the technique. In reality, these failures were due to the poorly designed nature of those individual systems, and it was found that some installation companies were not following guidelines set out by the Siphonic Roof Drainage Association.

Roofing Consultants always adheres to every guideline with regards to syphonic roof drainage, and you can be certain that a system installed by us will protect your commercial property from severe flooding. But how exactly does syphonic drainage work?

What is Syphonic Drainage?

Despite what its name may suggest the process of syphonic drainage does not actually involve the syphoning of water at all. Instead, syphonic drainage technology employs the use of a gravity induced vacuum pump to remove water at high-velocity from multiple roof drains at once.

This pump requires no external power as it is activated by rainfall filling the drain beyond its anti-vortex plate, at which point air flow to the pipe is cut off. The vacuum created along with the natural gravitational flow means the water is drawn horizontally from your roofing system and pumped towards a single downpipe to a location of your choosing.

A syphonic drainage system is not only cheaper to construct than a typical roof drainage system – especially when a large industrial roof has to be covered – but the system’s design means there is no need for the pipe pitch or gradients found in typical roof drain piping.

The vacuum pump does all the work instead, and you also have the added benefit that the anti-vortex plates make it difficult for anything other than water to penetrate the system. This means you will rarely have to deal with clogged pipes unless a breakage has occurred, as the pipes themselves are essentially self-cleansing with little need for maintenance. However, it is still recommended that your system is checked over by a qualified roof maintenance technician at least three times a year.

Within the United Kingdom you will find most drainage systems of any type are installed in a fashion which allows them to deal with a 108mm/hr rate of rainfall, a rate which tends to occur at least several times a year on average. With all roof drainage systems in the UK based on a 2 minute storm time, a good system needs to evacuate this water fully within one minute to reduce the risk of flood.

Syphonic systems are the most efficient method of doing this, and whilst they can be applied to most industrial roofing designs you must always ensure that your system is installed by competent syphonic drainage contractors make sure your system runs properly.

Contact Roofing Consultants today using our contact form for a quote.