Wet / Dry riser systems are intended for the use of fire services to provide a readily available means of delivering considerable quantities of water to extinguish or to prevent the spread of fire.
If your fire risk assessment concludes that you may need the intervention of the Fire and Rescue Service to fight a fire, you must ensure that your riser systems or hydrants are working properly. Before installation of dry or wet rising mains, the local authority and the Fire Officer must be consulted to ascertain their exact requirements. Dry risers will be found in buildings more than 18 metres above ground level and in lower buildings which have excessive distances from entrances (>60m). Wet risers can be found in buildings more than 60 metres above ground level.
A Dry riser system consists of valves and pipework enabling the fire service personnel to pump water from Ground Level to the upper floors of a building whereas a wet riser system consists of valves and pipework which are kept permanently charged with water, supplied by dedicated wet riser fire pumps and a water storage tank.