I was on a building site recently (not in NZ) which was using ACP for parts of the cladding. The panel had no markings that would allow me to trace back to what it should be. I asked for test certificates and a letter from the supplier stating that what they had supplied matched the test reports.
No letter or test report has been forthcoming. The client side project manager undertook an adhoc test on a panel off-cut and this was the result in the photo below. What do you think it indicates bearing in mind this is not a controlled test to any particular test standard? Prior to doing this test he took a cigarette lighter to an exposed edge of an offcut and it caught fire.
In contrast in NZ a contractor wanted to convince me of the safety of an FR core panel and took a blow torch to the panel. He succeeded to burn a hole in the panel where the flame impinged but did not get a lot of combustion beyond the direct flame area.
Unfortunately the test doesn’t indicate much useful information. It is pretty obvious that this is not installed to the manufacturer’s installation details with the edges exposed.
It is also entirely possible that the compliant panel may have combustible insulation material too.
For the NZ uncontrolled test I would expect a blow torch to put out a lot less heat than a cone calorimeter, so would also not produce a useful result. The results from both uncontrolled, non-standard tests could be considered a false positive and false negative.
For the first panel no evidence means that the product is non-compliant, in my opinion. Local regulations may differ from New Zealand but it is still reasonable to reject a product where it has no evidence supporting any claims made about its performance.
All those points aside Grenfell Tower had panels with exposed edges as the manufacturer’s details were not followed and the designer had created their own detail. I would say the sample in the photo does not seem like a fail safe option for ACP.
I thought most ACP cladding systems had exposed edges? The panels are often V cut and folded to make a shallow pan whcih also stiffens the edges, and the edges themselves have exposed core where they are cut from the sheet. See for example the sections in www.alpolic.com/alpolic-intl/downloads/installation.pdf.
It doesn’t matter if it as tested in the appropriate full scale test which should then match the construction.
The picture of Mike J’s burning panel to me looks dodgy to me.
Are there any on site methods or things to look for with the core and draw a conclusion?
There is an Alucobond YouTube video on methods of checking fire retardant properties of ACP panels: https://youtu.be/62UES3sLAT4. This video is mainly around checking for substitutions of Alucobond FR panels. It is still worth watching though.
Thanks Kenneth, Geoff and Robert,
Just a reminder for those of you in Auckland Dr Tarek Haddad will be speaking tomorrow in Auckland.
Location: Beca Auditorium. Beca House 21 Pitt St, Auckland
Date and Time: Tuesday 12th February. 4.30 arrival for 5pm start.
3A Composites - The Use of Aluminium Composite Materials in the Cladding of Buildings - Fire