Vertical riser

A vertical riser is any component that extends vertically through a building, including for example stairs and lifts, but the term is most commonly used to refer to ductwork, pipes, conduits and cables.

Vertical ducts should be carefully positioned in order to try and keep pipe and cable run lengths to a minimum, and also, in the case of pipework, to avoid unnecessary bends.

Since vertical risers generally breach floors, they can present a hazard in terms of enabling the spread of fire and so must be appropriately fire protected.

Other types of vertical riser include:

• Dry riser: Used to supply water within buildings for fire-fighting purposes. Dry risers do not contain water when they are not being used but are charged with water by fire service pumping appliances when necessary. For more information see: Dry riser.
• Wet riser: Used to supply water within buildings for fire-fighting purposes. Wet risers are permanently charged with water. For more information see: Wet riser.

NB The term ‘riser’ can also be used in relation to the components of stairs. A stair riser is the vertical face between the back of the tread of one stair and the front of the tread of the stair above. For more information, see Stairs riser.

[edit] Related articles on Designing Buildings

• Building services.
• Dry riser.
• Ductwork.
• Fire collar.
• HVAC.
• Joined-up thinking is key to building safely.
• Pipework.
• Stairs riser.
• Types of riser.
• Ventilation.
• Wet riser.