Fire-stopping service penetrations: what inspectors look for

Why do service penetrations matter so much?

A fire-resisting wall or floor is only as good as its weakest opening. Fire compartments, fire-isolated stairs and shafts are designed to hold a fire and its smoke for a set time, and services are the main reason those barriers get holes in them. Plumbers, electricians, data installers and mechanical contractors all need to cross compartment boundaries, often at different stages of the job.

An unsealed or wrongly sealed penetration lets flame, hot gases and smoke bypass the wall entirely. Plastic pipes are a particular risk because they soften and burn away in a fire, leaving an open hole unless a fire collar or similar device closes it.

The NCC’s Performance Requirement C1P8 requires a building element provided to resist the spread of fire to be protected, to the degree necessary, where penetrations occur for building services, so that an adequate level of performance is maintained. The Deemed-to-Satisfy (DTS) route to meeting it is C4D15. Our guide to passive fire protection explains how compartments and FRLs are set in the first place.

What does C4D15 of the NCC require?

C4D15 applies where an electrical, electronic, plumbing, mechanical ventilation, air-conditioning or other service penetrates a building element, other than an external wall or roof, that is required to have an FRL for integrity or insulation, or a resistance to the incipient spread of fire. The installation must comply with one of the following:

• Tested systems. The service, the building element and the protection method at the penetration must be identical with a prototype assembly tested to AS 4072.1 and AS 1530.4 that achieved the required FRL, or differ from it only in accordance with Section 4 of AS 4072.1.
• Metal pipes and insulation. An all-metal pipe system can comply with the tested-system route except for the insulation criteria relating to the service, if no combustible building element or material is within 100 mm of the pipe for 2 m from the penetration and it is not in a required exit.
• Ducts. Ventilation and air-conditioning ducts and equipment installed in accordance with AS 1668.1.
• Specification 13. Limited DTS details for metal pipes, metal or UPVC sanitary plumbing in certain buildings, wires and cables, and electrical switches and outlets.

Where an FRL is determined for the tested-system route, it must be confirmed in a report from an Accredited Testing Laboratory. The NCC’s guidance also notes that C4D15 applies to the service where it penetrates the element: the building element and the part of the service passing through it must match the tested prototype, even if the pipe on site does not extend as far as the specimen did in the test.

What are AS 1530.4 and AS 4072.1?

The two standards work as a pair.

• AS 1530.4 — Fire-resistance tests for elements of construction. It sets the furnace test that measures how long an element, or a penetration through it, maintains structural adequacy, integrity and insulation.
• AS 4072.1 — Components for the protection of openings in fire-resistant separating elements, Part 1: Service penetrations and control joints. It sets how service penetrations and control joints are tested and assessed, and its Section 4 governs how far an installed system may vary from the tested prototype.

The point to take from both: a fire collar, sealant or wrap is not “fire-rated” in the abstract. It achieves an FRL only as part of a tested assembly of a specific service, through a specific wall or floor, sealed in a specific way. Change the wall type, pipe material, pipe diameter or annular gap beyond what AS 4072.1 permits, and the evidence no longer applies.

When can Specification 13 be used instead of a tested system?

Specification 13 is a narrow DTS alternative based on established building practice, not a general substitute for testing. Its main rules are:

• Metal pipes. An all-metal pipe not normally filled with liquid must be copper alloy or stainless steel with a wall at least 1 mm thick, or cast iron or steel with a wall at least 2 mm thick, and kept 100 mm clear of combustibles for 2 m from the penetration. Each opening must be neatly formed, take only one pipe and be no closer than 200 mm to any other service penetration, and the gap must be fire-stopped.
• Wires and cables. The opening must be neatly formed and at least 50 mm from any other service, and no larger than 2,000 mm² for a single cable with a gap of 15 mm or less, or 500 mm² in any other case.
• Switches and outlets. Recesses must not extend beyond half the wall thickness or sit within 300 mm horizontally or 600 mm vertically of a recess on the other side.
• Fire-stopping material. It must be concrete, high-temperature mineral or ceramic fibre, or another material that does not flow below 1,120 °C, and must be packed and compressed as it was in testing.

Specification 13 does not apply in ceilings required to have a resistance to the incipient spread of fire, or to piping that contains a flammable liquid or gas. Larger cables and anything outside its limits need a tested system or a Performance Solution.

Are there extra rules for exits, shafts and joints?

Yes. Several other provisions catch penetrations that a C4D15 check alone can miss:

• Fire-isolated exits (C4D10). Fire-isolated stairs and passageways must not be penetrated by services other than permitted electrical wiring, certain pressurisation ducting, and fire service, water supply and test drain pipes.
• Floors and ceilings (C4D13). A service passing through a floor required to have an FRL for integrity and insulation must be protected by a compliant shaft or in accordance with C4D15.
• Construction joints (C4D16). Joints and gaps in and between fire-resisting elements must be protected with a system tested to AS 4072.1 and AS 1530.4.
• Smoke-proof walls (Specification 11). In Class 9a health-care and Class 9c buildings, openings around penetrations must be stopped to prevent the free passage of smoke.

What evidence should a fire-stopping installation have?

Under A5G3, evidence of suitability can include a CodeMark Certificate of Conformity, a report from an Accredited Testing Laboratory, a certificate from a professional engineer or appropriately qualified person, or other documentary evidence such as a Product Technical Statement. A5G2 requires copies to be complete copies of the originals.

The NCC’s guidance is specific about fire test documents. AS 1530.4 provides for a full test report, a regulatory information report and a test certificate, and only the first two contain enough information to show that an installation is identical with the tested prototype. A test certificate on its own is not enough.

A complete record for each penetration typically includes:

• Location. The level, grid reference and wall or floor type on a marked-up plan.
• System. The service type and size, the product used and the test report or assessment it relies on.
• Photographs. Before and after sealing, close enough to show the product and annular gap.
• Installer details. Who installed it, when, and their licence where one is required.
• Identification. Many projects and specifications require a durable label at each penetration so later trades and inspectors can trace it to its record. The NCC itself does not mandate a label, so check the project specification and state requirements.

In Queensland, installing and maintaining fire collars, fire-rated penetrations and fire-rated joint sealing falls under a QBCC passive fire protection licence class. In Victoria, the Building and Plumbing Commission’s practice note FS-02 sets out guidance and an installation checklist for service penetrations of fire-rated and smoke-proof walls.

What defects do inspectors find most often?

Most penetration defects come from three causes: the wrong system, the wrong installation, or no evidence. On site that looks like:

• No fire-stopping at all. Pipes or cables through a fire-rated wall or slab with an open gap, often above a ceiling or behind a riser door.
• Missing fire collars. Plastic pipes through slabs or walls without a collar, or with the collar on the wrong side for the tested configuration.
• Mismatched systems. A product tested in concrete used in a plasterboard wall, or a collar used on a pipe size or material outside its test.
• Clustered services. Several services crammed through one oversized opening when the evidence covers single services.
• Breached penetrations. A sealed penetration later cut open to add a cable, then left unsealed.
• Damaged walls. Plasterboard fire walls stopping short of the slab, or with holes left by removed services.
• No paper trail. A neat installation with no test report, no photos and no record of who did it.

The last item matters because it is often impossible to prove compliance once a ceiling is closed. Our guide to building defects in Australia covers how defects are identified and resolved.

Fire-stopping inspection checklist

• Confirm the FRL. Identify every wall, floor and ceiling that is fire-rated or smoke-proof.
• Match the system. Check the evidence covers that element, service type, material, size and gap.
• Check the documents. Hold full test reports or regulatory information reports, not certificates alone.
• Inspect before close-up. Book inspections of risers, ceilings and slabs before linings go on.
• Photograph everything. Record each penetration before and after sealing, with its location.
• Check exits and shafts. Confirm only permitted services pass into fire-isolated exits.
• Record installers. Capture installer names, dates and licence numbers where licensing applies.
• Hand over a register. Give the owner the penetration register with the essential safety measures records.

Penetrations installed after handover are the owner’s problem to control. Our guide to essential safety measures covers ongoing maintenance.

Frequently asked questions