All composite panels on residential apartment buildings which are part of the NSW government’s cladding rectification program should be removed where they have more than eight percent combustible material by mass within their core, an expert panel has advised.
And products containing combustible material of eight percent or less should be retained only if strict requirements are met.
In its first report since being established to advise on suitable products for replacement under the New South Wales Government’s Project Remediate program (see below), the NSW Cladding Product Safety Panel (CPSP) has outlined two criteria which it recommends should determine whether or not cladding on 214 residential buildings which have been determined to be high risk by the state’s Cladding Taskforce should be removed.
In cases where cladding is made of composite panels where the combustible content of the core exceeds eight percent by mass, the panel recommends that the cladding be replaced.
Where the combustible content of the cladding’s core is less than or equal to eight percent, it may be possible to retain the existing panels under a performance solution.
For this to happen, the solution would need to be demonstrated to meet the requirements under the National Construction Code (NCC) that the building resists the spread of fire via its external walls (Performance Requirement CP2).
To do this, a verification method known as CV3 will need to be used.
This requires that:
- the external wall system undergo and achieve satisfactory results during testing which satisfies requirements of Australian Standard AS 5113 (which uses large scale tests to determine a wall system’s tendency to spread fire)
- the wall system have cavity barriers installed
- the building be protected by sprinklers.
“The CPSP recommends that for Project Remediate, composite panels with a core comprised of greater than 8 per cent combustible material by mass need replacement,” the panel’s report read.
“The CPSP considers that performance solutions may be appropriate to retain composite panels with a core comprised of 8 per cent or less of combustible material by mass if they meet the BCA Verification Method CV3 …”
“… Such a solution must also be acceptable to the consent authority.”
The recommendations come as the NSW Government is pursuing its Project Remediate strategy.
The strategy aims to assist owners of 214 buildings which have been identified by the state’s Cladding Taskforce as being covered in high-risk material to have their cladding remediated.
The panel was established to advise the government on suitable products and systems to remediate cladding as part of the program.
Dangers associated with flammable cladding have been highlighted in the 2014 Lacrosse fire in Melbourne and the 2017 Grenfell fire in London.
In its report, the panel said its recommendations have been driven by several factors.
First, products which contain eight percent combustible content or greater fall into either the medium or high-risk categories for insurance under the guide to managing insurance risk published by the Insurance Council of Australia.
The advice is also in line with recommendations from Fire and Rescue NSW, which has concerns about both fire spread and the risk of falling debris from panels involved in a fire.
Third, several testing and research projects have found that products with 8-30 per cent combustible material have generally only achieved acceptable performance in large scale fire tests when combined with certain other fire spread inhibiting measures such as non-combustible insulation and cavity barriers.
With existing buildings, it can be difficult to determine whether these measures have been installed as information about them is often limited and that information which is available is often hard to verify.
As such, there can be no guarantee that cladding products with 8 to 30 percent combustibility are safe for occupants.
Finally, whilst it acknowledges that there is some risk with any combustible material, the CPSP argues that panels with a low combustible content (generally up to approximately 8 percent) contain a lower quantity of combustible materials that could contribute to the spread of a fire.
This is evidenced, the panel says, by a total calorimetry screening method developed for ACP in the UK which ranks the core materials into three categories aligning with a European classification based on the energy release. This forms the basis of the Insurance Council of Australia, and several other, risk ranking protocols.
Such panels have also been seen to pass the BS8414 large scale test in certain system assemblies – a British Standard describing test methods to assess fire safety of cladding applied to the external face of a building.
As such, risks associated with these products are sufficiently low that their retention may be feasible, the panel argues.
Whilst its overall recommendation is that products which are recommended for replacement be removed in full, the panel acknowledges that there may be minor areas where existing product may need to be retained for practical reasons.
This could include small areas of cladding around balcony fixtures or tiling which may be capped and left in place where full removal would require re-tiling or removing balcony fixtures.
In such cases, retention should occur via a performance solution and should occur only with a detailed risk assessment.
As well, the retention must not affect either occupant or fire fighter safety and must not give rise to fire spread between units or floors.
“In addition, combustible insulation and any other combustible component of the external wall should be removed, with the whole cladding system replacement undertaken using materials and systems as described in section 8 (of the report) below,” the panel said.
In its report, the panel nominated an initial tranche of four products which it has endorsed as being safe and appropriate for cladding replacement under the program.
Further products are expected to be endorsed in later tranches as evaluation and assessment continues.