Smoke Door Regulations
When fire breaks out in a building the risk to life safety is two-fold. Firstly there is the fire itself and the buoyant hot smoke generated in the immediate vicinity. Secondly there is the cooler smoke and toxic gases which, if unimpeded will rapidly spread through the building, threatening people and property some distance from the fire. Smoke doors provide a physical barrier that restricts the spread of smoke, assisting the occupants evacuation by ensuring egress routes remain clear and tenable.
Smoke doors are referenced by the BCA in Specification C3.4. This section outlines the general scope and requires that a smoke door must be constructed so that smoke will not pass from one side to the other and If it's glazed there is minimal danger of a person being injured by accidentally walking into them. The clause also provides a deemed to satisfy construction as follows;
Smoke door deemed to satisfy construction (DTS)
A smoke door of one or two leaves satisfies if it is constructed as follows:
(a) The leaves are side-hung and swing -
(i) in the direction of egress; or
(ii) in both directions.
(b)(i) The leaves are capable of resisting smoke at 200°C for 30 minutes.
(ii) Solid-core leaves* at least 35 mm thick satisfy (i).
(c) The door leaves are fitted with smoke seals.
(d)(i) The leaves are normally in the closed position; or
(a) The leaves are closed automatically with the automatic closing operation initiated by smoke detectors, installed in accordance with the relevant provisions of AS 1670.1, located on each side of the doorway not more than 1.5 m horizontal distance from the doorway; and (b) In the event of power failure to the door, the leaves fail-safe in the closed position.
(e) The leaves return to the fully closed position after each manual opening.
(f) Any glazing incorporated in the door complies with AS 1288.
(g) (i) If a glazed panel is capable of being mistaken for an unobstructed exit, the presence of the glass must be identified by opaque construction.
(ii) An opaque mid-height band, mid-rail or crash bar satisfies (i).
Fire Engineered (Performance-based) smoke door specification
The BCA permits the use of “Performance Based Alternative Solutions” and Fire Engineers now frequently reference two Australian Standards to create a comprehensive specification that details requirements for a complete door assembly AND a test methodology that allows actual leakage rates to be determined. The two standards commonly referenced are: AS6905:2007 & AS1530.7:2007
AS6905:2007 - Smoke Doors
This standard outlines the construction, installation and identification requirements for a complete smoke door assembly. Importantly this standard also provides guidance on the maximum acceptable leakage rates for both single and double leaf door assemblies. Smoke leakage rates are determined by subjecting a door assembly to the test method detailed AS1530.7.
AS1530.7:2007 – Methods for fire tests on building materials, components and structures. Part 7 – Smoke control assemblies – ambient and medium temperature leakage test procedure.
This Standard provides a methodology to measure and quantify the leakage of both ambient and medium temperature air through a door assembly. The test procedure involves mounting a door into a sealed chamber and heating the air within to a temperature of 200°C and maintaining this for a period of 30 minutes. At various stages pressures are induced within the chamber and the corresponding leakage measurement logged and reported.