Sometimes it’s great when you are the first to do something, sometimes it is not. I am really hoping someone else has used steel walls in a BAL Flame Zone, in NSW.
I have spent many hours interrogating Lord Google and writing to steel production companies, design forums that promote steel cladding, and a few builders and architects. It seems that these days according to AS 3959, Superman should have been the man of fibre cement, or 90mm thick brick.
However, there is a bit of potentially, slightly good news at the end of this week’s investigations.
I was very excited to find this steel and shipping container building in what looks a lot like a BAL Flame Zone (pictured above). But, that was not the good news. My tail stopped wagging when I found out from the architect that it is a temporary structure so it didn’t have to have a DA. I have since found mention of another steel building in a BAL FZ in NSW, although it mentions fibre cement as well, so I am hoping to hear back from the builder or architect from that project.
Then I boldly ventured further into the world of bushfire industry acronyms and bureaucracy. The best news so far has come from the CSIRO. I came across a study that tested a steel building against the flame zone standards (AS 1530.8.2.) – the roof and floor did well, the walls needed a bit more work (doh!). Then I found a more recent conference paper that ran some more tests on steel walls, and I contacted the lead author at CSIRO who was really helpful. He said that “there are a number of new provisions relating to steel construction specified by the NASH building standard which have been recently adopted into the BCA”. This translates to the National Association of Steel-framed Housing, whose building standards have been taken up by the Building Code of Australia.
In short, with the right insulation and internal wall construction, he reckons it should be possible to achieve BAL FZ with steel walls.
That is where the real fun started – the BCA is not meant to be read by normal people. I got to page thirteen thousand and something only to find I did not have the right amendment version. There appear to be lots of amendment documents and they all come up on Google as “BCA 1996”, rather than the year of the actual amendment. I am assuming that the 13th Amendment didn’t happen in 1996, if so someone did a really bad job on the original BCA.
I think the new provisions happened in 2013 or more recently, so have been trying to find the correct bit of the BCA. Well, I’m not now, I’ve written to NASH instead, the BCA can go jump in the lake because I don’t have 200 hours a week to spend on this. I would rather be picking out nice colours for the interior…assuming there will be an exterior at some stage to keep them in.
The other potential cost blow-out is the BAL FZ windows, which may require extremely expensive kryptonite-resistant glass and shutters. However, I found a helpful forum which seems to suggest that in NSW there is an exclusion on Clauses (e) and (f) of 3.7 in AS 3959. “Yipeeee” I thought, not knowing what the heck that meant but liking the sound of exclusions. What it means is that using BAL 40 twice (windows and shutters) might equal BAL FZ. More on that later. I am meeting a bushfire assessment consultant on site later this week and have a growing list of questions that I hope he can answer…