Fire safety in building design: proper documentation of service penetrations

Designers and engineers are reminded that service penetrations located within fire resistant elements and/or required smoke proof walls must have a protection method documented and be tested in accordance with the relevant standards.

Through the Victorian Building Authority’s (VBA) Building Documentation Audit Program of Class 2 to 9 buildings, it has been identified that the fire protection of openings for services installation and ventilation and air-conditioning ducts are not always adequately documented in the design documents to demonstrate compliance with Part C4 of National Construction Code (NCC) Volume one.

The most typical example of inadequate documentation identified by the VBA was missing information relating to fire dampers and/or smoke dampers for ventilation ducts penetrating through fire rated walls and/or smoke walls in a mechanical services layout design drawing.

The omission of fire and/or smoke protection of service penetrations in design documentation may result from any of the following factors:

• Failure to incorporate the fire rated walls and smoke wall details into the services installation drawings
• Changes to the floor plans at a later stage after the services drawings are completed
• Inattention.

Where a deemed-to-satisfy solution is adopted, designers and engineers must ensure that any service penetrations through a building element that is required to have a fire resistance level (FRL), with respect to integrity or insulation or a resistance to the incipient spread of fire, has a protection method documented in accordance with C4D15.

Where the protection method is a tested system, it must be tested in accordance with the relevant standards, including AS 4072.1 and AS 1530.4. Where the penetration forms part of a ventilation and/or air-conditioning system – compliance with AS 1668.1 is applicable for the installation, and in some cases Specification 13 may be applicable.

Where a deemed-to-satisfy solution is adopted and any service penetration passes through a required smoke-proof wall, compliance must be demonstrated against the provisions of NCC volume 1 Specification 11.

Whichever pathway is chosen by the designers must be clearly defined, documented and relevant evidence of suitability provided and verified.

Reviewing fire protection requirements

When reviewing the fire protection requirement provisions in services drawings services designers and relevant building surveyor (RBS) should:

• Cross-check the services design drawings with the final architectural drawings to ensure they are consistent and to make sure all the fire resisting building elements, smoke walls where required, and protection methods are detailed.
• If applicable, cross-check that the requirements of the Fire Engineering Report have been implemented and are coordinated with the services design.
• Ensure that where air conditioning or ventilation ducts are penetrating a fire resisting or smoke proof building element, a fire and/or smoke damper has been nominated to be installed.
• Check that air conditioning penetrations comply with AS 1668.1.
• Ensure that when a fire and a smoke damper are installed separately, the smoke damper shall be within 600mm from the fire damper or fire resisting/smoke-proof wall to comply with AS 1668.2.

It is important to note that AS 1682.2 is a secondary standard to AS 1668.1 which incorporates a specific requirement under section 6 clause 6.1 to provide convenient access for the commissioning and maintenance to the fire and fire/smoke dampers.

NCC volume 3 Vic variation E2P1 also states that mechanical services or plant and equipment for heating, cooling and/or ventilation must have access available for its maintenance.

It is therefore considered good practice for the RBS to request this information be shown on the services drawings as these may/may not cause an issue due to their location, for example not being permitted within a fire isolated exit. Check that a tested system proposed at the penetration is identical to the prototype assembly including the building element (type of construction it passes through), the service it is associated with, and the fire protection method itself matches that which has been tested in accordance with AS 4072.1 and AS 1530.4, and the relevant test reports from an Accredited Testing Laboratory have been provided.

The design documentation, including all relevant test reports to demonstrate compliance, should be presented to the RBS as part of the building services design works for their review and acceptance of the compliance as part of the building permit application.