Basement Smoke Make-Up Ductwork Systems

  • Smoke make-up fire duct is used to supply air to the fire compartment to assist with the air balance when smoke is being extracted from the building.
  • Mechanical and Natural Smoke extract requires appropriate means to allow make-up air. These systems are designed to either limit the extent of smoke spreading and/or to reduce the build-up of heat in the compartment.(BS9999:2017 ref. A.6.c )
  • Fire dampers should not be used in smoke make-up systems

Basement smoke extract system

The basement extract ductwork system ( shown ) must be suitable for clearing fumes and smoke from the basement level. The system should normally be rated for a minimum of one hour integrity and maintain at least 90% cross sectional area.

Where the ductwork leaves the compartment from which it serves ( shown ) it must maintain integrity and insulation fire ratings for the same period of time as the compartment through which it passes.

Fans classified to EN 12101-3 must be used in run and standby configuration.

Any in line equipment such as attenuators, VCD's etc. must be tested.

All fire rated ductwork and penetration seals must be tested to BS:EN 1366 Part 1 and classified in accordance with BS:EN 13501-3 by a recognised NAMAS/UKAS accredited laboratory.

Note: Final approval must always be obtained by the local building control and fire consultant before commencement of construction.