Dry risers are a form of internal hydrant for the fireman to use and are always charged with water. Wet risers are only required for building where the topmost floor is higher than 18.3 meters and less than 30.5 meters above the fire appliance access level.

Dry risers are normally dry and depend on the fire engine to pump water into the system. Dry riser system comprises a riser pipe with landing valves at each floor and to which rubber-lined hose with nozzles can be connected to direct the water jet at the fire. Breeching inlet into which the firemen pump water are provided at ground level and connected to the bottom of the dry risers.

A typical dry riser installation is shown as below.