Dry Riser and Wet Riser Systems Explained

Comprehensive fire protection is about much more than just sprinkler systems. And if you’re a buildings or facilities manager, you’ve probably noticed that there are a number of different options available that can help to minimise risk and boost the safety of residents, visitors, customers, and business owners.

Dry & wet risers are two of these options. But what are they? What’s the difference between the two systems? How can they improve safety? And, perhaps most importantly, is it a legal requirement to have one of these systems installed in the properties you manage? As experts in all aspects of fire safety and protection, we’re here to simplify the complexities, and explain dry & wet risers in a clear and concise way.

Exploring the similarities

If you’ve previously been confused about dry & wet risers, don’t worry! The two systems aren’t all that different from each other, and there are a lot of similarities. For example, both dry & wet riser systems are ultimately made up of a fixed network of pipes within high rise buildings. They’re used to ensure that firefighters have the necessary access to water in an emergency, when the height of the structure makes it difficult, or impossible, to utilise statutory fire hydrants or the engine’s supply.

Both systems are designed to provide a rapid source of water to upper floors should the need arise. Both systems must also – by law – be tested every 12 months. This is often the responsibility of the property owner or managing agent. At Eversafe, we offer a maintenance service that can handle all that for you.

The difference between dry & wet risers

Despite all these similarities, there are some significant differences between the two systems. As a property agent or facilities manager, it’s important to understand how dry & wet riser systems differ.

Dry risers

Dry risers are a legal requirement in buildings more than 18m tall. They’re typically only used in buildings between 18m and 50m, however, due to limitations in how they operate.

Dry riser pipe networks connect a ground floor inlet (usually an external inlet) with multiple internal outlets located across the higher floors of the building. The pipes are typically dry – hence the name. When needed, water is pumped throughout the network, enabling firefighters to attach their equipment to the closest outlet for an instant source of water. Outlets are usually located within every 900 square metres of floor, and are typically found in lobbies, stairways, and cupboards. The pressure limitations of pumped water mean that dry risers perform best in buildings under 50m, while those over 50m require a wet riser system.

Wet risers

Wet risers are a legal requirement in buildings over 50m tall as they provide better water pressure on higher floors than dry riser systems can provide. This is a fairly recent requirement, with pre-2006 legislation requiring wet risers only for buildings of 60m or more.

Wet riser systems are very similar to dry riser systems, although, as the name suggests, the pipe networks are kept constantly full through a pressurised supply. This will be in the form of either a storage tank or the mains. The outlet system across the floors remains the same. However, should a fire break out on higher levels, firefighters will have instant access to pressurised water, rather than water that is simply pumped through the system. Wet risers should, at the minimum, provide 1500 litres of water per minute, for a total of 45 minutes.

High rise protection

Fire protection throughout high rise buildings is more complex than fire protection for smaller structures. A building’s height can significantly affect both access to water and water pressure. To find out more about maintaining safety in taller buildings, get in touch with us here at Eversafe by dropping an email to info@eversafefire.com, or by calling the team on 01795 713123.