Ensuring safe fire containment when cabling

Fire issues such as detection, suppression and containment of fire and smoke aren’t normally a concern for the cabling industry — these are typically left to fire professionals.

However, they become paramount to cablers if they route cabling through building elements that are deemed as fire containment barriers.

Applicable regulations

Most regulations imposed on any industry generally revolve around safety for the public and for the industry itself. The mandatory cabling regulations for our industry — AS/CA S008 (products) and AS/CA S009 (installation) — are based on the ‘pillars’ of safety and network integrity. Key safety issues in the current S008 and S009 regulations are proximity of metallic telecommunications conductors to electrical conductors, earthing and exposure to laser emissions. The soon-to-released S008 and S009 revisions will add warnings about the newly introduced ES3 energy sources, which are classified as hazardous.

Australia’s building regulation — the National Construction Code (NCC) — doesn’t invoke cabling requirements. However, compliance must be factored in by cabling and all other services installed in buildings, as it is integral to the safety of building occupants — and thereby users of the building services.

While the NCC doesn’t specifically address cabling, it has relevance to telecommunications pathways, particularly concerning fire containment. Cablers aren’t permitted to reduce the integrity of any fire-containment measures within a building. Where designated fire-containment measures exist, services are permitted to run through them, but their integrity must be promptly reinstated using approved measures. (Note: The AS/NZS 3084:2017 ‘Telecommunications pathways and spaces’ standard provides excellent guidance on telecommunications pathways.)

The NCC comprehensively defines the purpose and applicability of fire-resisting building elements and other means to constrain the spread of fire in buildings e.g.

Clause C2.7  ‘Separation by fire walls’

• “(ii) Any openings in a fire wall must not reduce the FRL [Fire Resistance Level] required by Specification C1.1 for the fire wall...”

Clause C3.15  ‘Openings for service installations’

• “Where an electrical, electronic, plumbing, mechanical ventilation, air-conditioning or other service penetrates a building element that is required to have an FRL with respect to integrity or insulation or a resistance to the incipient spread of fire, that installation must comply with…Specification C3.15.”

The NCC addresses situations where cabling may pass through fire-resisting building elements, but requires the penetrations to not reduce the barrier’s FRL. Importantly, this imposes the responsibility to maintain the FRL on whoever makes the penetration.

The soon-to-be-released revised AS/CA S009 regulation has an updated fire-stopping clause to provide sound direction for cablers on what needs to be done when they encounter fire-resisting building elements obstructing their cabling pathways; as well as outlining their accountabilities when contemplating penetrations to these barriers.

Scenarios

Let’s consider penetrations in fire-resisting building elements in two distinct scenarios:

1. Cabling in new construction sites is commonly installed prior to building completion and typically before fire certification. Therefore, service installers may simply be instructed by the head-contractor/builder to route cabling through penetrations the builder has already made in fire-resisting building elements. In this instance, the builder would be responsible for reinstating the FRL of the barrier. But this doesn’t automatically remove a cabler’s duty of care to maintain safety in a building. For their own protection, it’s advisable for cablers to obtain a written statement from the head-contractor/builder that they are sealing the penetration to return the barrier to its designated FRL. If there’s no written statement on who is responsible for rectifying the penetration in the barrier, cablers may find themselves still accountable for losses incurred from a fire passing through the penetration, even years later.
2. Installing cabling in existing buildings — which may need to be routed through penetrations in fire-resisting building elements — is where a cabler is more likely to be confronted with the decision on what to do, thereby seeking directives on a compliant methodology. The building will already be deemed safe by fire professionals, so any penetrations in a fire-rated barrier would compromise the integrity of the building’s fire-safety certification. In this instance, cablers are advised to first consult with the building owner, or person responsible for the building’s ongoing compliance if a barrier is a fire-resisting building element. If so, the cabler must be fully aware — before doing anything else — that any penetration they make in that barrier will reduce its effectiveness to contain the spread of fire and that they can be held accountable for that compromise. However, they should not rush to increase their insurance policies. The NCC recognises this is a common occurrence in many buildings over their lifespan, and has recognised safe and reliable methods to effectively seal penetrations in fire-resisting building elements that return the barrier to its FRL. It requires penetration-sealing systems to be “tested in accordance with AS 4071 and AS 1530.4 and achieved the required FRL or resistance to the incipient spread of fire…The determination of the required FRL must be confirmed in a report from an Accredited Testing Laboratory in accordance with Schedule 5.”

Industry consultation

In consulting many industry stakeholders for this article, it was apparent that, while a heavy responsibility, sealing penetrations in fire-resisting building elements can and is being done safely and cost-effectively.

The Fire Protection Association of Australia stressed:

1. Anyone making a penetration in a fire-resisting building element is accountable for the reduction in that barrier’s fire containment and is therefore responsible to reinstate its FRL.
2. Given the emphasis on safety within buildings, standards for the various services within a building should be consistent with the fire regulations in the NCC.

Most of the electrical and cabling contractors consulted said their standard procedure in dealing with potential penetrations in fire-resisting building elements was to firstly consult with the facility manager or building owner to check if the barrier was fire-rated or not. If it was, they would make an appropriately sized penetration, route the cables and then seal it with an NCC-compliant method — typically fire-rated sealants or fire-collars. One electrical contractor cited the ‘Tested Systems’ outlined in Clause C3.15 of the NCC and said “It’s my go-to place to cover my butt.” Others said they occasionally used the spare capacity in existing penetration-sealing systems, and routed cables through them. In every instance, however, they were very conscious of their responsibility to not compromise the integrity of the barrier and took steps to ensure they didn’t reduce the integrity of what was already in place — effectively ‘covering their butts’ from fire-damage liabilities.

Cabling registrars commented that, where cablers had to penetrate a fire-resisting building element, many would take photos of any penetrations and cabling passing through them after being appropriately sealed and included them in TCA1 forms they submitted to clients and retained for their own records. Where they found existing penetrations they considered ‘dodgy’, they submitted TCA2 forms to formally distance themselves from sub-standard or possibly non-compliant work done by others.

Accountability

Fire-resisting building elements are designed and certified by fire professionals, who are held accountable for their determinations. This is typically carried out at the construction phase of a building, with the NCC stipulating the required fire-compartment compliance for specific building classifications. Once compliance is granted, the building is considered safe to occupy. However, anyone who creates penetrations that reduce the building’s fire integrity is accountable for that compromise and must take steps to reinstate that defined fire integrity.

Image credit: ©stock.adobe.com/au/Crystal light