Well, trotting at least. I’m back to a state of “so far so good”. I had the planned meeting with my bushfire assessor, and MgO or Modak board cladding sounds like a fine plan. He rang the RFS on the spot, and while they haven’t come across that FRL solution much, at least not for a container build, they reckoned it sounded OK.
They did in fact say “that’ll be a first”, which is the sort of thing that makes my teeth grind a bit in worry these days, but as my sensible bushfire assessor pointed out, a wall with an FRL of 60/60/60 would mean the window systems they approve on a daily basis would combust or blow out in a fire before this proposed system would. We agreed that seems like a good basis on which to give it a go.
Since then I ran into a local builder at the Blackheath hardware store who said Modak is heavy and hard to work with, and he prefers Ezylite. He’s just done a house in a flame zone in the Ezylite board. That sounds like another good solution for other folks, but is not as high on the list for me as it is rated as part of a wall system that includes plasterboard. If I can’t have container steel showing on the outside, I want some showing on the inside, and Modak gets the FRL rating without having to include plasterboard. So I will plug on and chat to a few more people to get some more info on just how nasty Modak is to work with.
So, Modak/MgO is the wall cladding solution I am going with for the DA. The roof and roof top deck will be the same board as well (they come in thicker decking board options), with a lining of colourbond over the one container that has a proper roof just to channel water into the gutters, but no eaves or extra bits added on.
I popped into the Sydney home show on the weekend. It was sort of fun to wander into the stalls and say the words “flame zone” and watch the faces of the sales people fall in disappointment and the sales pitch drop flat to the floor. Although the main reason I went was more productive than that, to look at materials and get some ideas. One happy discovery is that there is now a local Blue Mountains supplier of aluminium decking, which looks easy to apply and has a good finish on it.
I spent a lot of time looking at screens, as the standard screens that come with my container would be diamond grille which would murder my view, or at least maim it. Particularly for my 4m wide sliding glass doors in the living room facing the view, I wanted something more transparent. “That’s lovely, does that come in 2mm steel mesh with no diamond grille?” I would ask.
Anyway it turns out that I need to refresh myself on the AS 3959 and RFS variations, I admit it has been a while since I pondered over them, which was a blissful break. The screens have to be fixed on the openable portions of windows. Windows and glazing are kind of thrown together in the standards, so I figured glass doors were included. They are thrown together unless you look carefully, as it turns out, but if you read it properly (memo to me, pay more attention when reading Australian Building Standards) the screens are NOT required on doors, of any sort. This was just confirmed by my very helpful local architect Ross, who pointed out that people leave windows open when they go out and the screens would stop embers from floating in, but people tend to shut doors when they leave the house. How very practical, full marks to the RFS again.
So all I need is a pretty darn big bushfire shutter over those doors, which will not be cheap and may have to be automated – but when the shutter is up and the place is flame free I will have a lovely clean view from the living room.
This long weekend will be full of DA plans. That is good. That is progress. Nevertheless, I can feel some more G&Ts coming on…