Last edited 28 Oct 2019

Appliance ventilation duct

Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses (2019 edition), defines an appliance ventilation duct as:

'A duct to deliver combustion air to a gas appliance.'

Where an appliance ventilation duct passes through a compartment wall or compartment floor, or is built into a compartment wall, each wall of the duct should have a fire resistance of at lease half the wall or floor in order to prevent the by-passing of the compartmentation.

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