What is the difference between wet and dry risers?

Many commercial, industrial and non-residential properties rely on wet and dry risers as a critical part of their fire safety procedures, but what is the difference between these two important features?

Although both wet and dry risers do similar jobs, they have fundamental differences. Wet risers are designed for buildings that are taller than 50m, and they have a constant supply of water that can be accessed by emergency services during a fire. This is achieved by using water storage tanks and pumps to create enough pressure to provide a water supply that can tackle any outbreak of fire on every floor of a high-rise building. Wet risers can be located inside or outside a building and feature two outlets that are connected to water pipes, which firefighters will then access to tackle a blaze.

On the other hand, dry risers are necessary for buildings taller than 18m, and they are not permanently filled with water. Instead, they make use of an interconnected system of pipes that can swiftly provide firefighters with a supply of water on the upper floors of a building. Dry risers provide easily accessible ports to which the fire brigade can hook their hoses while extinguishing a fire. This means firefighters do not have to worry about carrying additional equipment and resources into the building, to help them tackle the emergency faster. For dry risers to operate successfully, pipework, external inlets and internal outlets are required. These elements must be made to the highest possible standard and manufactured in line with BS 5041, BS 5306, BS 9990, and building approval regulations.