What fire rating do service penetrations need in Australia?

Under NCC 2025 Specification 13, every service penetration through a fire-rated wall or floor must maintain the element's Fire Resistance Level (FRL) for integrity and insulation. The penetration seal FRL is expressed as -/YY/ZZ because structural adequacy is not required. For example, a wall rated 90/90/90 requires penetration seals rated -/90/90.

What is AS 4072.1 and how does it apply to fire stopping?

AS 4072.1-2005 is the Australian Standard for fire stopping systems in service penetrations and control joints. It requires that all fire stopping products be tested as a complete system per AS 1530.4, matching the specific service type, pipe size, gap size, and substrate. Individual components without system-based test evidence are not compliant.

What is the difference between a fire collar and a fire wrap?

Fire collars contain intumescent material that expands in a fire to crush and seal plastic pipes (PVC, HDPE, PE). They suit new construction where clearance is available. Fire wraps serve a similar purpose but suit retrofit situations and space-constrained penetrations where collars cannot fit. Both must be tested and certified to AS 4072.1 for the specific service and substrate.

How is Fire Resistance Level (FRL) expressed for penetration seals?

FRL is expressed as three numbers in minutes: structural adequacy / integrity / insulation. For penetration seals, structural adequacy is not required, so the rating uses a dash: -/YY/ZZ. For example, -/120/120 means the seal stops flames for 120 minutes and limits heat transfer for 120 minutes.

Can electrical outlets be placed back-to-back on a fire-rated wall?

Under NCC 2025 Specification 13 (S13C6), electrical outlets on opposite sides of a fire-rated wall must be offset by at least 300 mm horizontally or 600 mm vertically. Back-to-back outlets without this offset compromise the wall's fire resistance.

Fire Resistance Levels and Service Penetrations

Section 1

What You Need to Know

Every pipe, cable, and duct that passes through a fire-rated wall or floor creates a weak point. The NCC (National Construction Code) requires those gaps to be sealed so the wall or floor keeps its fire rating. Get it wrong, and fire and smoke spread between compartments. This memo covers the rules, the products, and the mistakes that catch people out.

Section 2

The Rules

Every service penetration through a fire-rated element must maintain the element's FRL (Fire Resistance Level) for integrity and insulation (NCC 2025, Specification 13)
Fire stopping systems must be tested as a complete assembly per AS 4072.1 and AS 1530.4 (NCC 2025, Specification 13)
Fire-stopping material must not flow below 1120 °C when tested per ISO 540 (NCC 2025, S13C7)
In hollow walls and floors, fire-stopping must be packed to 25 mm thickness around the service for the full length of the penetration (NCC 2025, S13C7)
Metal pipes need 100 mm clearance from combustible materials for 2 m either side of the penetration (NCC 2025, S13C3)
Electrical outlets on opposite sides of a fire-rated wall must be offset by at least 300 mm horizontally or 600 mm vertically (NCC 2025, S13C6)

Section 3

What This Means in Practice

A penetration seal does not need a structural adequacy rating. Its FRL is expressed as -/YY/ZZ. If a wall is rated 90/90/90, the seal around every pipe and cable through that wall must achieve -/90/90. That means it must stop flames for 90 minutes and limit heat transfer for 90 minutes.

For a typical commercial building with fire-rated corridor walls and floor slabs, every trade creates penetrations. Hydraulic pipes, electrical cables, data cables, mechanical ducts, and fire sprinkler pipes all pass through rated elements. Each one needs a tested, certified seal that matches the specific service type, pipe size, gap size, and wall type. A fire collar tested on a 150 mm concrete slab cannot be used on a plasterboard wall without separate test evidence.

The most common problem on site is late-stage penetrations. A data cabling contractor drills through a fire-rated wall after the fire stopping is done. Nobody re-seals it. That single hole can void the fire rating of the entire wall. Coordination and inspection at handover are the only reliable fixes.

Section 4

Key Design Decisions

1

Tested System vs. Deemed-to-Satisfy

Specify tested systems (AS 4072.1 pathway) for all penetrations. The deemed-to-satisfy route in Specification 13 is restrictive: it requires 200 mm between services, one pipe per opening, and limits penetrations to two fire compartments. Tested systems give more flexibility and are easier to verify on site.

Trade-off: Tested system products typically cost $15–80 per penetration depending on size, but they simplify compliance and reduce rework risk.

2

Fire Collar vs. Fire Wrap vs. Sealant

Fire collars suit plastic pipes (PVC, HDPE, PE) in new construction. Fire wraps suit retrofit or space-constrained situations. Intumescent sealants suit cables and small services. Pick the right product for each service type and substrate.

Trade-off: Collars are fastest to install but need clearance around the pipe. Wraps work in tighter spaces but take longer to fit.

3

Penetration Scheduling and Coordination

Require all trades to mark penetration locations on coordination drawings before any core drilling. This prevents ad-hoc holes through fire-rated elements and lets the fire stopping contractor plan the work in one pass.

Trade-off: Adds coordination time during shop drawings but avoids costly re-inspection and re-sealing later.

4

Documentation and Passive Fire Register

Maintain a passive fire register with photos, product data sheets, and test report references for every sealed penetration. Certifiers and fire auditors expect this at handover.

Trade-off: Takes 5–10 minutes per penetration to document, but is the only way to prove compliance during audits and defect liability.

Section 5

Who Needs to Know What

Section 6

References

National Construction Code 2022, Volume One, Specification 13 — Penetration of walls, floors and ceilings by services
National Construction Code 2022, Volume One, Part C3 — Compartmentation and separation
AS 4072.1-2005 (R2016), Components for the protection of openings in fire-resistant separating elements — Part 1: Service penetrations and control joints
AS 1530.4-2014, Methods for fire tests on building materials, components and structures — Part 4: Fire-resistance tests for elements of construction
AS/NZS 1668.1-2015, The use of ventilation and airconditioning in buildings — Part 1: Fire and smoke control in buildings

Fire Resistance Levels and Service Penetrations

What You Need to Know

The Rules

What This Means in Practice

Key Design Decisions

Tested System vs. Deemed-to-Satisfy

Fire Collar vs. Fire Wrap vs. Sealant

Penetration Scheduling and Coordination

Documentation and Passive Fire Register

Who Needs to Know What

Need this engineered for your project?

References

Related design memos

Fire Damper and Smoke Damper Requirements

Smoke and Fire Damper Testing After Installation

Fire Rated Ceilings and Service Penetrations