Tuesday, September 23, 2014

The roof/ceiling space - an extremely vital bushfire-protection chore

Have you looked in your roof/ceiling space lately?  Ember ignition here during bushfires is a major cause of house destructions.

This Bendigo house was destroyed in 2009 when the bushfire's embers started fire in the roof-ceiling space. 

Before it gets too hot, shine a torch in there. Are ceiling and rafters coated with the  accumulated dust of years? This is highly flammable. Are there rats’ or birds’ nest? Old papers? Clean it out! If you  can’t physically do this yourself, there are firms that specialise in this. If you don’t have an inspection trapdoor, make one.

Crawl in and shine the torch up. Do pinpricks of light show through the roof? Bushfire embers could enter here. Solder or otherwise plug gaps in roofing metal; fasten and seal loose tiles.

These are extremely vital bushfire-protection chores.
The ceiling space is very vulnerable. A tile or galvanised iron sheet lifted by strong wind, a nail hole, a gap in the eaves, can let in flying sparks and embers.
Even a spark can ignite roof dust and eventually ignite rafters. Slowly and unseen, fire builds up, gases erupt, and up goes the whole roof space. This can take hours. It often starts after a fire front has passed, while the ember shower is still falling  If shelterers are ignorant of what is happening above them, a flaming ceiling collapses in. Too many bushfire deaths and house losses happen this way. They need not. 

                             The SA historic home, ‘Wolta Wolta’, destroyed on Ash Wednesday, 1983. 
While Wolta Wolta's owners rejoiced that the fire front had passed them by and were relaxing with a cup of tea, fire was stealthily building up in the roof space.

          Embers can’t penetrate roofs if you have continuous metal sheeting and/or roof sprinklers. 
      - best are low flow sprinklers. And have enough water to run them.
Fill cracks with Expanda Foam or a fire resistant expandable epoxy-type such as Nullifire.
Insulate above and below rafters.
     Insulate with mineral wool, fibreglass batts or aluminium foil laminate.

On the day:
Keep inspection door open, with ladder against it with a torch, and water in knapsack or garden sprayers, handy just inside it. And, of course, wear protective clothing.