Dry vs Wet Risers

You must have heard about the wet and dry risers, but you most likely do not know their fundamental differences. As far as fire safety in high-rise buildings is concerned, risers prove to be of high significance. 

They make the supply of water to every floor possible within the shortest time. The two main types of dry and wet risers have their own merits and demerits. Therefore, very clearly differentiating between these two is going to benefit building owners as they make their choices.

In this article, we will help you differentiate between dry and wet risers. It will also discuss what might prove beneficial while considering one for your building.. 

Dry Risers and How They Work

A dry riser is a system of empty pipes and valves requiring inlets and outlets. They are used in buildings between 18 and 60 meters tall and designed for firefighting. 

These systems are installed during construction; they remain empty until needed in an emergency fire situation.

Firefighters connect a fire engine to the ground-level inlet valve. Then the water is sent through the system, enabling efficient firefighting on upper floors. Dry risers are cost-effective and avoid water damage risks under normal conditions.

Wet Risers and How They Work

 

A wet riser is a system of pipes permanently filled with water, ready for immediate use during fire emergencies. It is typically installed in buildings over 60 meters tall. 

Connected to a constant water supply from a municipal system or dedicated tank, these systems are always under pressure. They provide instant water access at each floor’s outlets for quick firefighting. 

 

Installation is complex, requiring pressure regulation, and maintenance involves regular checkups. While wet risers offer immediate water availability and reduced response times, they pose risks of leaks and water damage.

Difference Between Wet and Dry Risers

Below are some of the major differences between wet and dry risers:

• Water Presence

    The most significant difference between dry and wet risers is the presence of water. Dry          risers are empty and require connection to an external water source during an                          emergency. In contrast, wet risers are permanently filled with water and ready for                      immediate use.

• Water Supply

   Dry risers require water from an external source, usually a fire tender. This can result in the     slowing down of operations as the firefighters need to engage and pump water into the         system. Wet risers, on the other hand, are linked to a source of water which can be                   municipal water or an internal water supply tank, hence readily available.

• Legal Requirements and Regulations

   Standards of international and local fire safety dictate the design, installation, and                  maintenance requirements. This is to ensure the systems function effectively during                emergencies. Compliance with these regulations is essential to ensure the safety and legal    responsibility of building owners and managers.

• Installation and Maintenance

   Wet risers require to be installed with more effort. They often undergo some maintenance       so as to check on the flow and the pressure of the water. This includes daily pressure               checks and examination of valves, and outlets on the lines. 

   One the other hand, dry risers which are less complicated structures, must also be                   periodically checked and tested. This is to determine their state of readiness for                         connection to an available water supply in a fire incident.

• Cost Considerations

   It is costly to install and maintain wet risers due to the level of complicacy and the                     requirement of a steady supply of water. Dry risers, though less complex than wet riser systems, ask for the extra step of connecting to a water supply source.  Still, they are cheaper than the former.

Where Are Wet and Dry Risers Found?

Wet risers are often used in tall buildings, for example apartment buildings, offices, and hotels above the 60-meter mark. This means that these buildings need water ready for use in case of outbreak of fire. 

Dry risers are preferably installed in medium and high risks building that usually ranges from 18 meters and above. These include buildings for living, for business, and other structures such as factories. the height makes it easier for firefighters to connect and external water source.

Do Wet and Dry Risers Need to Be Regularly Tested?

Yes, both wet and dry risers require regular testing and maintenance. This is done to ensure they are operational in an emergency, as mandated by fire safety regulations. 

For dry risers, this includes checking inlet and outlet valves and ensuring pipes are unobstructed. Verifying the water supply and pressure levels for wet risers is important. Checking for leaks or other issues is also done that could impact performance.

How to Choose the Right Riser System?

Following are some of the considerations to keep in mind while choosing a riser system for your property: 

Building Height and Size:

The height and size of your building play a significant role in determining the appropriate riser system. 

If your building is of a medium height, typically 18m to 60m, you should consider getting a dry riser. It is also a quicker system and has fewer disadvantages. 

For buildings taller than 60 meters, wet risers are recommended due to their ability to provide immediate water availability. 

Budget

Budget is another crucial factor. While dry risers are more cost-effective to install and maintain, they require fire engines to supply water during emergencies.

Wet risers, although more expensive, offer the advantage of immediate water access. This can be a lifesaver in tall buildings.

Risk Assessment

Conducting a thorough risk assessment is essential. This involves evaluating the potential risks of water damage from wet risers against the need for quick firefighting response times. 

Wet risers, being constantly filled with water, pose a higher risk of leaks and water damage. Conversely, dry risers, being empty until needed, eliminate this risk but may delay firefighting efforts slightly.

Conclusion

Understanding the difference between dry and wet risers is essential for safety. Dry risers are cost-effective and reduce the risk of water damage. This makes them suitable for buildings up to 60 meters tall. 

Wet risers are preferred in tall structures as they can access water rapidly. They are widely employed in systems that require very low latency periods.

Maintenance in both systems is equally important to ensure they meet safety measures. You may need to find out the building’s characteristics, how much money you have, and its fire safety needs.