Temporary Stairs During Construction or Demolition

Written by Kyle Cameron, Assistant Project Manager

When existing buildings are undergoing demolition or construction, the Chapter 33 of the New York City building code requires that existing means of egress and fire protection devices (elements) are maintained at all times. Chapter 33 allows for temporary elements to be in place when an existing element has been removed from the building during demolition. For example, if an egress stair is going to be demolished and rebuilt, a temporary staircase should be installed as a way of maintaining the egress during demolition and construction operations. An existing egress stair cannot be demolished until the temporary staircase has been installed and inspected. A temporary staircase cannot be demolished until the new permanent staircase has been installed and inspected. There are three different types of temporary staircases that can be used during demolition and construction: scaffold stairs, system stairs, and prefabricated stairs.

Scaffold stairs are integrated within pipe scaffolding on the façade of the building. Scaffold stairs are used for a smaller elevation gain. These stairs are set at an incline of 60 degrees. With the incline of the stair being steep, the riser height is typically 9 inches, and the tread depth is 11 inches. Due to the slope of the scaffold stairs, they cannot be used by the Fire Department to negotiate a stretcher or carry any equipment in the event of emergencies. This is typically used by construction personnel only – the trade for example, masons – who are performing the immediate work.

Another type of temporary staircase that is used is a system stair. System stairs can be installed either inside or outside the building as a means of egress when replacing an interior egress stair. If installed inside the building, the stair would have to be enclosed in a two-hour fire rated enclosure with 1 ½ -hour fireproof self-closing doors. These stairs have less of an incline at approximately 45 degrees, rather than 60 degrees for a scaffold stair. System stairs typically have a riser height between 7 inches and 9 inches and a tread depth of between 9 inches and 11 inches. System stairs are typically 7 feet wide with a 3’-6” wide landing platform at every level.

The last type of stair that can be used is a prefabricated stair. Like the system stair, the prefabricated staircase can be installed inside or outside the building as a means of egress when replacing an interior egress stair. The prefabricated stair most resembles an interior egress stair with a 7-inch riser and 11-inch tread. These stairs have the smallest incline at 30 degrees rather than 45 degrees for a system stair or 60 degrees for a scaffold stair, making them the preferred option for the fire department to negotiate a stretcher during emergencies.