Author Topic: Good engineering can save lives from bush fires  (Read 2526 times)

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Offline VK3DRB

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Good engineering can save lives from bush fires
« on: November 09, 2019, 01:13:41 pm »
As you may have heard, parts of NSW and QLD are on fire and people have died. Hundreds of houses destroyed. Another catastrophe. Yep, we have heard it all before and its going to happen again. I think a bit of common sense engineering based on electronics practices could have saved a lot of homes and lives.

In electronics, we design products to work to a set of requirements. We obey standards and we get approvals. We ensure the PCBs and components are UL-94 or similar fire rated so they don't catch fire. We use components that are to operate within their specifications and environment. So, why don't we apply the same principles to building fire proof homes?

I lived in a bush fire risk area for 13 years. I applied common sense engineering principles to build my home myself out of steel frame brick veneer and solid brick. The roof trusses were steel, the insulation in the walls and ceiling were fireproof, the fascias and verandah ceilings were cement sheet. The floors were tiled and the lounge room carpet was wool. The window frames were aluminium. All around the house there was 2.3m concrete verandah. There was nothing to burn! On top of that, the grass was kept low around the home on the few acres we had and there was always water available. A bush fire came within 500m of our house once, but I was not worried.

Why on earth do the civic authorities in California and around Australia continue to allow wooden framed houses with wooden trusses and wooden gutter fascias and wooden door and window frames to be built where embers ignite these materials? It is insane. A recipe for disaster. I noticed on the news tonight one woman "miraculously" discovered her house did not burn down - it was a rammed earth building. Incidentally, termites don't eat steel frames. If electronics were designed like houses in these fire prone areas, we'd be charged with professional negligence and probably end up to jail.

Note that in electronics we obey standards. Same should apply with houses; and the standard should be no flammable materials should be used in house construction in fire prone areas, make them UL-94 rated! And that includes not allowing inflammable cladding into the country. Or aren't people's lives and homes worth it?
« Last Edit: November 09, 2019, 01:17:05 pm by VK3DRB »
 

Offline BravoV

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Re: Good engineering can save lives from bush fires
« Reply #1 on: November 09, 2019, 01:27:37 pm »
Simple, some just never heard of the 3 little pigs story, or forgotten completely ...  :-DD

« Last Edit: November 09, 2019, 01:29:09 pm by BravoV »
 

Offline GeorgeOfTheJungle

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Re: Good engineering can save lives from bush fires
« Reply #2 on: November 09, 2019, 02:27:01 pm »
You did it well. Good for you! But... please, big brother pokes its nose into too many things already.
git diff *
 

Offline chickenHeadKnob

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Re: Good engineering can save lives from bush fires
« Reply #3 on: November 09, 2019, 06:01:52 pm »
As you may have heard, parts of NSW and QLD are on fire and people have died. Hundreds of houses destroyed. Another catastrophe. Yep, we have heard it all before and its going to happen again. I think a bit of common sense engineering based on electronics practices could have saved a lot of homes and lives.

-- snip--
Why on earth do the civic authorities in California and around Australia continue to allow wooden framed houses with wooden trusses and wooden gutter fascias and wooden door and window frames to be built where embers ignite these materials? It is insane. A recipe for disaster. I noticed on the news tonight one woman "miraculously" discovered her house did not burn down - it was a rammed earth building. Incidentally, termites don't eat steel frames. If electronics were designed like houses in these fire prone areas, we'd be charged with professional negligence and probably end up to jail.
--snip--


Speaking from a Canadian perspective -- Wood frame houses are the established norm here in North America and you would generate significant pushback from the construction and lumber industries which are huge  employers. The wood frame is not the predominant fire contagion risk, it is the cladding and roofing materials. In particular cedar shake roofs and vinyl (PVC) siding and trim are the worst offenders by wide margin.  Personally I am already biased against the esthetics of shake roofs, but many here on the west coast like them.

The cedar shake lobby/industry used to claim the fire retardant infused into the shakes was sufficient and  would claim it lasts 10+ years. Actual tests suggest the fire retardant weathers out in about 2 years. Which is why they are slowly being banned. However building codes are a local thing so there is no uniformity.

 When you see the results of a crowning fire that has swept by a housing division and has only selectively burned a house here or there you can see striking differences in fire performance of cladding materials side by side. I am thinking in particular of a fire in the interior of British Columbia, perhaps the big Kelowna fire. That fire was dropping embers 100's of meters ahead of the fire front. It magically selected some shake-roofed houses to burn and left the others houses alone, cluestick time. After the big Fort Mac fire some of the suburbs burned out completely which is what the news outlets focused on but occasionally the camera would pan and you could see  the houses on the periphery of the burned area. One house would look fairly unaffected while the neighbour with PVC siding would exhibit half of the siding melted off,  dripping and scorched simply from radiant heat.
 

Offline German_EE

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Re: Good engineering can save lives from bush fires
« Reply #4 on: November 09, 2019, 07:44:44 pm »
I've watched dozens of episodes of a programme called 'Holmes on Homes' and the type of materials used to build a home in North America continue to amaze me, and not in a good way. I've seen internal walls made from wood and plasterboard rather than brick, roofs covered by some thin artificial material designed to look like overlapping slate, wires joined by wire nuts, cables not in conduit and the whole thing slapped together using nails rather than screws. Crazy!

In sixty years I've never lived in a European property that wasn't built of brick or concrete and It's been so long since I saw a house fire that I don't remember when it was.

So, build a home solid enough to last a hundred years and the fire risk will probably be reduced as well. Add to that proper management of the land around the building including clearing away anything on the ground that can burn and maybe a few lives could be saved.

Finally. plastic cladding, NO! It looks ugly, it's a fire risk and it means that the outside surface of the wall can't breath.
Should you find yourself in a chronically leaking boat, energy devoted to changing vessels is likely to be more productive than energy devoted to patching leaks.

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Offline VK3DRB

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Re: Good engineering can save lives from bush fires
« Reply #5 on: November 10, 2019, 05:35:02 am »
A metal framed home should last about 150 years, only needing the corrugated zincalume roofing replaced every 50 years. I built my old place to withstand cyclonic winds.

In Australia many of the fires start with hot embers or ash in gutters where the wooden fascia and trusses are nearby.

I am aware too a lot of houses in the USA are poorly built, having lived there. When Hurricane Andrew hit, the media asked one bloke why his home was the only one standing in the neighbourhood, to which he replied "I built it myself and followed the building code."

But in the house I live in now, the wiring was done not by by professional sub-contractors, but by professional sub-morons who left earth wires off a number of points (earth wires not connected but left clearly dangling in mid-air behind the wall).

It is estimated by an architect that about 70-90% of all recently built high-rise apartments (flats) here have structural problems. Many were built with illegal flammable cladding imported from China. Our state government has announced they will get the taxpayer to foot much of the bill to replace this cladding, rather than making the perpetrators (govt ministers/developers/builders) FULLY accountable. The architect said the problem here is so bad, another Grenfell Tower episode in Australia is not a matter of if, but when.

https://www.afr.com/property/residential/australia-s-high-rise-apartments-face-crisis-of-our-own-making-20190724-p52a8g


 
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Offline Halcyon

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Re: Good engineering can save lives from bush fires
« Reply #6 on: November 10, 2019, 08:44:07 am »
I feel for those who lost their homes, possessions and loved ones, but I don't think the responsibility just rests with authorities. I myself live in a bush fire prone area and was a fire fighter for 5+ years. Although I built my home from a timber frame (on purpose), I took other steps to ensure my house is protected, even simple things like metal fly screens can make all the difference when it comes to ember attack.

Fire season after fire season I've seen homes destroyed where the occupants put off maintenance such as keeping gutters clean, trees lopped and general fuel cleared from around the house. It's far too late when a fire approaches.

 

Offline vk6zgo

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Re: Good engineering can save lives from bush fires
« Reply #7 on: November 10, 2019, 09:31:02 am »
Most of the older houses in the suburbs around Perth, WA are double brick, with, yes, wooden rafters & usually  trim.
They are not too bad for fire safety, but they will burn, if the fire gets inside.
In the older forestry areas, many homes were built with "weatherboard"(for non Oz folks, they are "boards" specially shaped to overlap neatly).

They are, in many cases, very neat & picturesque, but after 80--100 years of sitting there drying out, they are a bushfire's "favourite food".
In many cases, back in the day, the frames were retained, but reclad in (aiiieeee!!! :scared:) asbestos.

"Asb" or "fibro" is fire resistant, but has a habit of shattering if exposed to enough heat for long enough.

Meanwhile, back in the city, increasing numbers of homes are made, using softwood framed "brick veneer" .
A few years back,there were a lot of steel frames being built, but the softwood ones seem to be in the majority now.

In the "hills" east of the city, there are some very nice properties nestling amongst quite large eucalypts.
To add insult to injury, many are either all wood construction, or have very large polished wood feature walls.

For us peasants, the new houses on "postage stamp" blocks (I don't have one of them) have about a hand's width between them, so if a fire starts a one end of a group of them...

Some of them are made of premade concrete panels & assembled on site, so should be pretty good, but I
don't know whether they have compromised that with other materials added later.
 

Offline VK3DRB

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Re: Good engineering can save lives from bush fires
« Reply #8 on: November 10, 2019, 12:57:58 pm »
I feel for those who lost their homes, possessions and loved ones, but I don't think the responsibility just rests with authorities. I myself live in a bush fire prone area and was a fire fighter for 5+ years. Although I built my home from a timber frame (on purpose), I took other steps to ensure my house is protected, even simple things like metal fly screens can make all the difference when it comes to ember attack.

Fire season after fire season I've seen homes destroyed where the occupants put off maintenance such as keeping gutters clean, trees lopped and general fuel cleared from around the house. It's far too late when a fire approaches.

I agree, some homes up in the Dandenong Ranges here need serious fire prevention maintenance. Surrounded by undergrowth and eucalyptus trees. These people seem to forget the fires of '83 when 47 people were burnt to death up there. People need to be protected from their own stupidity by government legislation. "Give me a home among the gum trees" is asking for trouble. In the Black Saturday bush fires, no amount of clearing and maintenance could save some homes, as embers could travel several kilometres. Building material paradigms need to change, and good engineering design will help define standards.

Personally I dislike trees, unless they bear fruit or are suitable to host a ham radio antenna. The Europeans have the right idea, having their cities devoid of trees. Home owners should be allowed to demolish any trees they want on their own land without a permit, and without the Greenie-infested councils fining them.
 

Offline GeorgeOfTheJungle

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Re: Good engineering can save lives from bush fires
« Reply #9 on: November 10, 2019, 01:50:04 pm »
[...]
People need to be protected from their own stupidity by government legislation.

Oh please.

Personally I dislike trees, unless they bear fruit or are suitable to host a ham radio antenna. The Europeans have the right idea, having their cities devoid of trees.

Watt? You are talking complete bollocks.
git diff *
 

Offline SeanB

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Re: Good engineering can save lives from bush fires
« Reply #10 on: November 10, 2019, 04:32:16 pm »
Years ago I was watching CNN, which was then ( for us) giving realtime Gulf War ( still just Gulf War, later Gulf War 1) coverage from Bhagdad. Switch to the London offices, and are reporting on the heatwave hitting London then, with temperatures exceeding 30C, and people dying from heatstroke, and bathing in the fountains. Sitting down for tea at 10, and asked my colleague Raven when was it 30C in here. His reply was "just after quarter past seven", and please note this was winter as well in the southern hemisphere.

Then they popped over to LA, where there was yet another fire burning, and the CNN anchor is out there in a burnt out subdivision, talking to a resident. Korean engineer, standing there outside his house, standing alone in the whole subdivision as being the only one left, and asked him why his house was still there.  He looked at her, told her "I built it myself, and thought everybody know, wood burns".
 

Online andy3055

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Re: Good engineering can save lives from bush fires
« Reply #11 on: November 10, 2019, 05:25:18 pm »
I always wondered about this wild idea: What if each household was allowed to have a locally pressurized water storage system that is connected to an external sprinkler system that would cover the roof and the outside walls that will get activated in case of a fire?

If I lived in my own remote piece of land, that is what I would do.
 
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Offline Bud

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Re: Good engineering can save lives from bush fires
« Reply #12 on: November 10, 2019, 06:10:25 pm »
, cables not in conduit and the whole thing slapped together using nails rather than screws. Crazy!
Do not know what they use these days but my 30 years old house has twist nails all around. It is nails with spiral flute along the shank. I can tell i have hard time each time i renovate something and need to pull the nails out. It is freaking hard and I wish i'd rather had screws. Twist nails hold extremely well.
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Offline RandallMcRee

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Re: Good engineering can save lives from bush fires
« Reply #13 on: November 10, 2019, 06:28:42 pm »

Timber-frame construction in California has saved countless lives...from earthquakes.

Fires are somewhat new on the scene, I suppose we need to find some compromise. But still, its probably more cost-effective to have appropriate fire breaks around the property than to use, say, brick, which is never recommended in an earthquake area.

https://pdfs.semanticscholar.org/e7a3/d7e79d63ddc7b501b6d992a73f45c7d1abf4.pdf
 
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Offline richard.cs

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Re: Good engineering can save lives from bush fires
« Reply #14 on: November 10, 2019, 06:39:51 pm »
I always wondered about this wild idea: What if each household was allowed to have a locally pressurized water storage system that is connected to an external sprinkler system that would cover the roof and the outside walls that will get activated in case of a fire?

If I lived in my own remote piece of land, that is what I would do.
This was discussed on the California fires thread. It looks like it's been done and works well. It needs a big tank and a reliable, low-maintenance pump that will operate without external power, and ideally can be triggered remotely or by the fire. It's clearly an expensive thing to implement so the economic benefit is unclear, but then saving your house isn't just about the rebuilding cost.

I suggest it's better as an addition to rather than substitute for non-flammable roof coverings.
 
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Offline chickenHeadKnob

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Re: Good engineering can save lives from bush fires
« Reply #15 on: November 10, 2019, 07:12:40 pm »
, cables not in conduit and the whole thing slapped together using nails rather than screws. Crazy!
Do not know what they use these days but my 30 years old house has twist nails all around. It is nails with spiral flute along the shank. I can tell i have hard time each time i renovate something and need to pull the nails out. It is freaking hard and I wish i'd rather had screws. Twist nails hold extremely well.

Nails are in the building code for a reason - shear strength at 90 degrees to the shaft is better than screws. Ardox nails do have good pull out grip.
 

Online SiliconWizard

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Re: Good engineering can save lives from bush fires
« Reply #16 on: November 10, 2019, 07:32:03 pm »
[...]
People need to be protected from their own stupidity by government legislation.

Oh please.

Personally I dislike trees, unless they bear fruit or are suitable to host a ham radio antenna. The Europeans have the right idea, having their cities devoid of trees.

Watt? You are talking complete bollocks.

That was fun.
 :-DD
 

Offline Zero999

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Re: Good engineering can save lives from bush fires
« Reply #17 on: November 10, 2019, 10:06:10 pm »
Years ago I was watching CNN, which was then ( for us) giving realtime Gulf War ( still just Gulf War, later Gulf War 1) coverage from Bhagdad. Switch to the London offices, and are reporting on the heatwave hitting London then, with temperatures exceeding 30C, and people dying from heatstroke, and bathing in the fountains. Sitting down for tea at 10, and asked my colleague Raven when was it 30C in here. His reply was "just after quarter past seven", and please note this was winter as well in the southern hemisphere.
The UK is mostly north of 50 parallel and exposed to sea breezes all the time, so temperatures are normally in the low 20s in summer, although 30C is not that uncommon in south east England. There are normally a few days that temperature near London every year. Above 35 is rare, although it happened the last two summers.

People get used to the local climate. If to got below freezing where you live, not far from the tropics, people would drop like flies.
 

Offline nctnico

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Re: Good engineering can save lives from bush fires
« Reply #18 on: November 10, 2019, 10:12:02 pm »
Timber-frame construction in California has saved countless lives...from earthquakes.

Fires are somewhat new on the scene, I suppose we need to find some compromise. But still, its probably more cost-effective to have appropriate fire breaks around the property than to use, say, brick, which is never recommended in an earthquake area.
Still a fire-proof cladding of the home would help. I don't think there is much you can do against embers hitting your home so making sure they won't set anything on fire is probably the best option. A fire break will help though even if it just limits the amount of fuel to the fire.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 
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Online andy3055

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Re: Good engineering can save lives from bush fires
« Reply #19 on: November 11, 2019, 12:39:41 am »
I always wondered about this wild idea: What if each household was allowed to have a locally pressurized water storage system that is connected to an external sprinkler system that would cover the roof and the outside walls that will get activated in case of a fire?

If I lived in my own remote piece of land, that is what I would do.
This was discussed on the California fires thread. It looks like it's been done and works well. It needs a big tank and a reliable, low-maintenance pump that will operate without external power, and ideally can be triggered remotely or by the fire. It's clearly an expensive thing to implement so the economic benefit is unclear, but then saving your house isn't just about the rebuilding cost.

I suggest it's better as an addition to rather than substitute for non-flammable roof coverings.

That is exactly my point. If saving valuable property and all what a family has that can be "valued," not to mention the destruction to their lives, I think it is well worth it.  It may not be that costly if it is done on a large scale. After all, you need very little hardware other than the space for a tank to hold sufficient water for a couple of hours worth.  Spraying with high efficiency sprinkler heads pointed only at the walls and a pipe line laid on the roof that ends in sprinkler heads to put out  falling embers, can very well make a difference. I bet some one will get the idea soon and make it a business! Insurance companies will love the idea. Imagine the savings they will have!
 

Offline Halcyon

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Re: Good engineering can save lives from bush fires
« Reply #20 on: November 11, 2019, 05:55:12 am »
I always wondered about this wild idea: What if each household was allowed to have a locally pressurized water storage system that is connected to an external sprinkler system that would cover the roof and the outside walls that will get activated in case of a fire?

If I lived in my own remote piece of land, that is what I would do.

Not such a wild idea at all, in fact some homes in Australia which are at the highest risk bush fire have exactly this kind of system. If you're at the top end of the scale, your construction is deemed "non-compliant" and you will need to satisfy the council that you can reasonably mitigate risks before your development application is approved. In fact, water tanks are mandatory on most new homes and the size is determined by the footprint of house. The smallest tank I was allowed to have on my property was 15,000 litres.
 
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Offline Berni

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Re: Good engineering can save lives from bush fires
« Reply #21 on: November 11, 2019, 06:50:34 am »
These cheap wooden houses aren't just a issue for fire. In Florida hurricanes rip them up too.

So in response after the disaster they build them again because they are cheap and quick to build. I once saw a press photo after a huricane that showed such a typical wooden house shattered in pieces all over the road, not a single wall left. But then in the background you could spot a old fashioned brick house that was still standing just fine and was only missing some of its roof.

Here in Europe brick houses are by far the most common and i don't think i have ever seen a natural event like that bring one down. Sure nature is a bit more forgiving but we do occasionally get weather extremes in small areas. Things that knock over entire trees causing blocked roads, damaged power lines... etc but the houses are fine. About the worst is that the strong winds throw some of the brick roof off or in rare cases rip parts of the roof straight off. The rest of the building is fine.

But that being said not all houses here are solid brick all trough anymore. Drywall is becoming more and more popular for interior walls due to how cheap and convenient it is. Even the doors are not solid wood anymore. These cheep hollow corrugated mesh material doors are more and more common, i'm guessing you can kick right trough one of those just like in the movies. With the doors we used to have 20 years ago all you would do is hurt your foot and leave a bit of dirt on the door.
 

Offline VK3DRB

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Re: Good engineering can save lives from bush fires
« Reply #22 on: November 11, 2019, 08:18:38 am »
[...]
People need to be protected from their own stupidity by government legislation.

Oh please.


Why do you think the government enforces speed limits on the road.

People who live in bush fires areas where their house is surrounded by undergrowth and have a plethora of eucalyptus trees very close to their home (ie: a fire trap) should be fined for their own good. That is good government.
 

Offline Moshly

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Re: Good engineering can save lives from bush fires
« Reply #23 on: November 11, 2019, 08:20:24 am »
This house was protected in the 2009 Kinglake fires


But I heard that some systems failed because ->
A: Electric pump with no backup generator.   :--
B: Feed pipes plumed above ground, made from PVC.  :palm:
 
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Offline VK3DRB

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Re: Good engineering can save lives from bush fires
« Reply #24 on: November 11, 2019, 08:30:41 am »

Timber-frame construction in California has saved countless lives...from earthquakes.

Fires are somewhat new on the scene, I suppose we need to find some compromise. But still, its probably more cost-effective to have appropriate fire breaks around the property than to use, say, brick, which is never recommended in an earthquake area.

https://pdfs.semanticscholar.org/e7a3/d7e79d63ddc7b501b6d992a73f45c7d1abf4.pdf

I agree that brick is not the best in earthquake zones, but why not steel frame rather than timber? Steels flexes. I am note sure, as I have never lived in an earthquake zone.

Here is a list of why steel frames are better overall:

Steel is not one the termites' menu.
Steel is fireproof.
Steel is usually pre-punched with holes so you can easily add cables inside walls.
Steel is very strong.
Steel (gal) lasts around 150 years in most places.
Steel frames are bolted or Tek-screwed together - far strong than any nails.
Steel frames don't warp.
Steel frames have similar expansion coefficient to plasterboard.
Steel frames homes (in Australia) can attract a much lower premium from some insurance companies.

But steel frames take more labour to erect.
 


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