Good engineering can save lives from bush fires

[Halcyon]

I agree that brick is not the best in earthquake zones, but why not steel frame rather than timber? Steels flexes.

Whilst Steel frames have many advantages, they aren't entirely "fire proof" as they can buckle and weaken with extreme heat. They also conduct heat more readily than timber which can then transmit into more combustible materials (causing them to melt/burn). Some other disadvantages include:

- Prone to corrosion
- A better conductor of heat (bad in hot climates)
- Joints can be noisy due to expansion/contraction and can lead to cracking of interior walls
- More expensive than timber frames
- More difficult to hang objects fixed directly to the frame
- Susceptible to fatigue and fracturing

Also despite being "termite-proof" it's still an important consideration as termites will ignore the steel but migrate to areas where other materials can be attacked. It's important not to neglect termite protection, even with a steel structure.

There is no "one size fits all" building material, it just depends on the location, design, budget and environment.

[GeorgeOfTheJungle]

There is no "one size fits all" building material, it just depends on the location, design, budget and environment.

And the budget is key. What we have is, usually, the best we can afford. That's why this mentality is dangerous:

People need to be protected from their own stupidity by government legislation.

[GeorgeOfTheJungle]

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

Why do you think some do not?

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.

IMO you should better mind your own bussiness. And read 1984 too.

[vk6zgo]

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. 

Back in the day, when I worked at a number of attended TV sites, some of them had large water tanks with IC engine driven pumps, so in the event of a fire taking out the power Mains, water was available to hydrants that could take the(then) standard fire hoses.
At the first place, the pump motor was a Holden "grey motor" which came up to speed fast, allowing an almost immediate useable flow.(there were remote start butons on each hydrant).

A problem there was that the thing ran on standard petrol, with the required tank itself a fire hazard.
Because of this, the next place was fitted with a biggish single cylinder diesel, which was quite capable of the required pwer, but built up speed so slowly that the water flow was fairly poor.
In fact  it remained poor when it got up to operating speed.

A modern installation would probably work best by using electric pumps, with auto changeover to a small diesel  emergency power plant.

[Berni]

Id imagine the biggest problem with steel is the cost of the material.

Brick is cheep, but the labor to build a brick wall and finish it into a nice looking painted state is huge. This is why drywall is catching on here since its also really cheap but takes much less work to build and to run cables and pipes inside it.

Steel framed buildings seam to mostly be popular in industry here because they are very quick to put together provided you have a crane to lift them in place. The thing is plenty strong to hold various industrial machinery. The walls are often made from panels of insulation sandwiched between sheet metal. This makes things pretty fire resistant in case there is a industrial mishap. Holes can easily be put into walls when additional piping or wiring needs to be run. I have yet to see a residential home here built this way in my parts of the world.

But woodframed drywall has the cost advantage in all aspects. All of the material is cheep and its easy to just quickly nail and screw things together. Combined with the "spend it all" attitude of Americans not having huge savings and the fact that its common practice to build such houses makes them seam very attractive options.

Same reason why people opt for a cheep car. Okay sure its 0 to 100 time might be measured with a calendar, the ride is unfomrotable, the interior is plastic crap and its most remarkable feature is that the radio can play a MP3 from a thumb drive. But it gets you and your cargo from A to B with less cost in gas and maintenance.

[richard.cs]

A modern installation would probably work best by using electric pumps, with auto changeover to a small diesel  emergency power plant.

Possibly, a submerged pump is desirable as this avoids all issues of suction height and priming, and that suggests remote drive, which could be electrical or mechanical. Diesel is OK for standby use, but needs a reasonable amount of maintenance to be reliable. My inclination would be more towards propane as you can store it indefinitely, and so long as the starting battery is float charged off the grid there's almost nothing that needs doing to keep the system ready to go, maybe set it to crank over without fuel every so often to circulate the oil a bit.


I put some thoughts on the other thread https://www.eevblog.com/forum/chat/californians-out-of-electricity-cant-get-gasoline-to-generators!/msg2758166/#msg2758166

[voltsandjolts]

"Good engineering can save lives from bush fires"

Indeed. It is heart breaking to watch this destruction, from both human and environmental perspectives.
I can't help but notice the irony though; "Good engineering" got us to this ugly situation in the first place, starting with the discovery of fossil fuels.

[vk6zgo]

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

Why do you think some do not?

Very few do not have some limits--- maybe none on the open road, like Western Australia when I was first driving, but urban & suburban areas usually have quite strict speed limits.

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.

IMO you should better mind your own bussiness. And read 1984 too.

It is his business.
Taxpayers money is used for relief of people whose houses have burnt down, and insurance companies increase everybody's premiums when they get a lot of claims.

I don't think "Big Brother" gave a stuff about whether his subjects were firesafe.
In any case, there are a lot of things the local council can fine you for now, which are a lot less life threatening.
Perhaps, in the interest of fire safety, they could trade a few of their more pettifogging rules for VK3DRB's one!

[VK3DRB]

I agree that brick is not the best in earthquake zones, but why not steel frame rather than timber? Steels flexes.

Whilst Steel frames have many advantages, they aren't entirely "fire proof" as they can buckle and weaken with extreme heat. They also conduct heat more readily than timber which can then transmit into more combustible materials (causing them to melt/burn). Some other disadvantages include:

- Prone to corrosion
- A better conductor of heat (bad in hot climates)
- Joints can be noisy due to expansion/contraction and can lead to cracking of interior walls
- More expensive than timber frames
- More difficult to hang objects fixed directly to the frame
- Susceptible to fatigue and fracturing

Also despite being "termite-proof" it's still an important consideration as termites will ignore the steel but migrate to areas where other materials can be attacked. It's important not to neglect termite protection, even with a steel structure.

There is no "one size fits all" building material, it just depends on the location, design, budget and environment.

Agreed, steel will buckle with heat, but it is ember attack on wooden framed homes that is the common cause to ignite a house fire.

Corrosion? Frames are galvanised. In areas away from the sea, at least 150 years before they corrode. Corrugated zincalume - 50 to 75 years.

Heat conduction? I never noticed any walls inside heating up. And we had hot days exceeding 40 deg C.

Noisy? Never noticed anything, except from the steel roof when a cloud comes over on a blue sky hot day. I lived in one for 13 years and I never noticed anything much. The roof covered 40sq, or about 400 sqm.

Expensive? Yes, more expensive than PINE timber frames. But the raw steel is still cheap. Generally you prefab the steel walls prior to putting them up and joining them. But the labour is more expensive if you have to pay someone to do it.

Difficult to hang something? I totally disagree. It is far, far easier with steel. Your electronic stud finder will find the centres no problem. The Tek screws are much more versatile and very strong. The steel frames have pre-punched internal holes to route cables. Nothing better. In addition, the frame acts as a Faraday cage to some extent which can be good or bad, depending upon what you are doing.

Steel frames are not susceptible to fatigue and fracturing if they have been MIG or TIG welded properly and the joints painted over and the interconnecting Tek screws are put in place properly.

Overall, steel is superior, but it does take more labour to assemble. If I ever built another house again myself, I would use steel, not using pine - especially if building in a fire-prone area.

[Halcyon]

but it is ember attack on wooden framed homes that is the common cause to ignite a house fire.

Yes, ember attack is largely the reason why homes are lost in bush fires but this isn't limited to homes with a timber frame. Even if the frame was directly exposed to flame (i.e.: no brick veneer etc...) it's still quite difficult to burn. Have you tried burning a solid block of wood? It takes a relatively long time and a lot of heat for it to cause a self-sustaining fire. Embers alone won't do it. Even then, the frames of most homes are insulated with brick on the outside.

House fires caused by embers are due to other sources of ignition such as leaf litter in gutters, combustible materials around the home, dry grass etc... An ember is enough to ignite those fuels, which causes a fire that grows and eventually causes enough flame to impact on the structure of a house. A steel frame won't do anything to protect you from a house fire if you have easily combustible materials around your home. Once fire gets into the roof space and starts burning things like insulation, wiring, plastics etc... it's game over.

Using metal fly screens, installing weep hole vents rated for fire, keeping your gutters clear and removing combustible items and plants away from your home will have a much greater impact against bush fire compared to building with steel frames.

Overall, steel is superior, but it does take more labour to assemble. If I ever built another house again myself, I would use steel, not using pine - especially if building in a fire-prone area.

Again, this depends. It's like saying "PC's are superior", in what context? In some cases, timber frames, double-brick, concrete walls can be "superior".

When I built my home, I decided to go with a timber frame even though I live in a bush fire prone area. My home was rated at BAL-29 but the timber frame still complied. The additional cost to go steel would have provided no added benefit for me.

By the way on another note, this is what happens to steel in a bush fire:



This image was taken in 2013 in Winmalee, NSW. Whilst that steel beam in the photo didn't burn itself, it conducts a lot of heat and will cause anything combustible attached to or near it to burn. It's like grabbing a hot fire poker and shoving it in a pile of paper.

[jetsam]

Forbidding wooden framing would really badly hit the cost of construction and maintenance, and we're already in a housing crisis in California and have been for decades now.  Nobody under 35 who isn't one of the lucky few can afford to get in on the housing market, even at the entry level.  Millennials are starting to live in vans because it's the only way to get out of their parents' homes...

That said, I think you're absolutely right.  Good engineering and code improvements could really help mitigate this wildfire risk.  The problem is threatening to just cream our economies long term (California's and Australia's.  We're like step sisters.  We share the same problems, but sleep in different beds after marrying poorly )  It'd be worth billions if it could be done well.

I wish stuff like that were easier to implement flexibly.  Over-regulating the market will only undermine it further.  If done well, regulation can really work, though, and faster than any other way of addressing the issue can.

My thoughts are with you, Aussies.   Stay clean and breathe well.  I hate the fires, now.  I used to love a camp fire... now, not so much.

[NiHaoMike]

Whilst that steel beam in the photo didn't burn itself, it conducts a lot of heat and will cause anything combustible attached to or near it to burn. It's like grabbing a hot fire poker and shoving it in a pile of paper.

Maybe there's a way to make the sprinkler pump self powered by the heat? As in a steam engine?

[vk6zgo]

Forbidding wooden framing would really badly hit the cost of construction and maintenance, and we're already in a housing crisis in California and have been for decades now.  Nobody under 35 who isn't one of the lucky few can afford to get in on the housing market, even at the entry level.  Millennials are starting to live in vans because it's the only way to get out of their parents' homes...

That said, I think you're absolutely right.  Good engineering and code improvements could really help mitigate this wildfire risk.  The problem is threatening to just cream our economies long term (California's and Australia's.  We're like step sisters.  We share the same problems, but sleep in different beds after marrying poorly )  It'd be worth billions if it could be done well.

I wish stuff like that were easier to implement flexibly.  Over-regulating the market will only undermine it further.  If done well, regulation can really work, though, and faster than any other way of addressing the issue can.

My thoughts are with you, Aussies.   Stay clean and breathe well.  I hate the fires, now.  I used to love a camp fire... now, not so much.

We have regular "wailings and gnashings of teeth" over the possibility of terrorist attacks, with money being forthcoming for prevention of such things.

Of course, money for fire prevention & firefighting is a lot harder to get, because it isn't "sexy"!

In the meantime, one halfwit with a box of matches can cause more devastation than the average terrorist could achieve in his wildest dreams!

[David Hess]

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.

In earthquake areas the give that nailed joints provide helps prevent catastrophic failure.  I lived through several earthquakes in California and unreinforced masonry (bricks) were always a major problem.  For timber homes the biggest issue was cracked stucco which is not a structural problem.

A couple weeks ago my basement stairs collapsed under me while I was standing at the top; it was quite a ride which left me looking up at the ground floor at midnight wondering how I would get back up.  The original *government inspected and approved* design had the top of the stairs fastened to the ground floor with nails in tension!  WTF?  After raising the stairs with double tackle, I refastened them with construction screws rated for the application, added safety chains to an adjacent double joist, and anchored the stairs at the bottom.  They no longer meet government mandated building code but since it almost killed me, I no longer care to follow it.

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.

When I lived in the area 20+ years ago, one homeowner setup exactly that with water sourced from his pool.  The local government ordered it removed because it could never be approved and pool water was reserved for firefighters to use during emergencies; tanker trucks and water dropping helicopters fill up at people's pools if needed.  This was right about the same time that local governments were ordering people to remove foliage and brush around their homes because of the fire danger and the EPA was ordering them not to because of endangered species.  I discarded sympathy for voters in California long ago; they support these policies.

[andy3055]

I hate the idea of getting into arguments with members on this board as I believe the intent here is to throw possible innovative ideas on various issues faced by all of us everywhere.

Having said that, I do not believe that EPA and the local governments being at the opposite ends of an issue warrants the statement “I discarded sympathy for voters in California long ago; they support these policies.” I also believe that no one needs any sympathy from anyone else in this day and age. People choose where to live and how to live and they have to abide by the laws and regulations therein and face the perils that come with them though there are many instances where people vote for all sorts of idiotic ideas. These comments are not meant to anger anyone but to bring to light how innovative ideas get politicized. So, let us all try to stay away from the politics. Thank you.

[David Hess]

My point is that California's problems are entirely political and that is where an "innovative" solution will have to be applied.  Good engineering is futile where it cannot be applied.

[chickenHeadKnob]

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.

In earthquake areas the give that nailed joints provide helps prevent catastrophic failure.  I lived through several earthquakes in California and unreinforced masonry (bricks) were always a major problem.  For timber homes the biggest issue was cracked stucco which is not a structural problem.

A couple weeks ago my basement stairs collapsed under me while I was standing at the top; it was quite a ride which left me looking up at the ground floor at midnight wondering how I would get back up.  The original *government inspected and approved* design had the top of the stairs fastened to the ground floor with nails in tension!  WTF?  After raising the stairs with double tackle, I refastened them with construction screws rated for the application, added safety chains to an adjacent double joist, and anchored the stairs at the bottom.  They no longer meet government mandated building code but since it almost killed me, I no longer care to follow it.

I have built my own wood frame house and participated in building others, the comment about shear strength came directly from a conversation with my local building inspector. A nice chap with an engineering degree. Actually we were mainly discussing the various  merits of glue lam versus other types of built-up structural wood beams.

Sorry to hear about your mishap. I now know why you were missing from action recently from this forum! I was beginning to worry about you. I suspect your stairs implementation was not code approved and just escaped attention somehow. It happens, tract builders getaway with all kinds money saving shortcuts.

An aspect of brick buildings in earthquake zones is that after they collapse a fire then often breaks out in the rubble, as the combustible interiors and ruptured natural gas lines subsequently get exposed to a source of ignition. If a high magnitude earthquake hits the old part of Vancouver, with its inventory of 100 year old multistory brick buildings I expect the same outcome as the San Francisco quake 1906 when the post quake fire killed more people.

[David Hess]

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.

In earthquake areas the give that nailed joints provide helps prevent catastrophic failure.  I lived through several earthquakes in California and unreinforced masonry (bricks) were always a major problem.  For timber homes the biggest issue was cracked stucco which is not a structural problem.

A couple weeks ago my basement stairs collapsed under me while I was standing at the top; it was quite a ride which left me looking up at the ground floor at midnight wondering how I would get back up.  The original *government inspected and approved* design had the top of the stairs fastened to the ground floor with nails in tension!  WTF?  After raising the stairs with double tackle, I refastened them with construction screws rated for the application, added safety chains to an adjacent double joist, and anchored the stairs at the bottom.  They no longer meet government mandated building code but since it almost killed me, I no longer care to follow it.

I have built my own wood frame house and participated in building others, the comment about shear strength came directly from a conversation with my local building inspector. A nice chap with an engineering degree. Actually we were mainly discussing the various  merits of glue lam versus other types of built-up structural wood beams.

The shear strength issue makes sense because the sharp edges of a screw concentrate stress.  On the other hand, that can be taken into account by using a larger cross section and better materials but of course that adds to the cost.

In my case, the top of the stairs were attached to the first floor with plain steel nails in tension so eventually they just pulled out of the wood; friction was the only thing holding them and the stairs in place.  I replaced them with construction screws specifically rated for structural use (not drywall screws) and made improvements for safety.

Sorry to hear about your mishap. I now know why you were missing from action recently from this forum! I was beginning to worry about you. I suspect your stairs implementation was not code approved and just escaped attention somehow. It happens, tract builders getaway with all kinds money saving shortcuts.

Naw, that was a disagreement with our local ISP plus my 20+ year old dual Xeon server finally expiring.  It only took me a week to put the stairs back up and honestly, I lucked out with only getting banged up although I had some pretty serious bruises.

An aspect of brick buildings in earthquake zones is that after they collapse a fire then often breaks out in the rubble, as the combustible interiors and ruptured natural gas lines subsequently get exposed to a source of ignition. If a high magnitude earthquake hits the old part of Vancouver, with its inventory of 100 year old multistory brick buildings I expect the same outcome as the San Francisco quake 1906 when the post quake fire killed more people.

One area I lived in for many years in Orange County, Southern California was all electric (with aluminum wiring!) for that stated reason and in theory the homeowner's insurance was less although I do not think it worked out that way.  It was built back in the era when nuclear power (from San Onofre) would be too cheap to meter and we know how that turned out.  The lack of gas service combined with the typical lack of insulation contributed to very high utility bills.

There are not many brick buildings remaining in Southern California because past earthquakes destroyed most of them but there are lots of brick chimneys which come down with every 5.5 or greater.  Construction practices there have required post stressed concrete foundations now for a while although I am dubious if that matters.

[Marco]

I still think there should be some way to quickly pull a reflective tarp over a home.

Launching weighted darts to pull it across should work with enough weight, but even with plenty of padding those darts are going to be pretty dangerous.

[VK3DRB]

I agree the first line of defence is to remove trees, bracket, leaves etc from around a house.

When we had our Black Saturday bush fires in 2009 (180 dead, massive amounts of property lost), one council fined a bloke for clearing trees which would have otherwise burned his house down. It cost him $100K in legal costs to fight the council. https://www.smh.com.au/national/fined-for-illegal-clearing-family-now-feel-vindicated-20090212-85bd.html

I once had to pay $500 in wasteful costs imposed by the council and supply a large volume of paperwork over a period of several months to get a permit to remove a single non-native deciduous tree from my own land, else risk an $8000 fine. The leaves were a fire risk. I asked the council officer why people have to pay and go through all this to remove trees from their own property and the answer was, " If we didn't charge, everyone would be removing trees, ruining the aesthetic appearance of the district." Of course, that is utter , because before they started charging, people were not stripping the suburb bare of trees. Anyone should be able to remove whatever trees they want off their own land. I am sure houses have been lost in bush fires because of the religious fanaticism from tree-huggers.

[David Hess]

I still think there should be some way to quickly pull a reflective tarp over a home.

I saw a product like that but it took several men like half a day to install which seems to me like a good way to fall off of a roof.

I once had to pay $500 in wasteful costs imposed by the council and supply a large volume of paperwork over a period of several months to get a permit to remove a single non-native deciduous tree from my own land, else risk an $8000 fine. The leaves were a fire risk. I asked the council officer why people have to pay and go through all this to remove trees from their own property and the answer was, " If we didn't charge, everyone would be removing trees, ruining the aesthetic appearance of the district." Of course, that is utter , because before they started charging, people were not stripping the suburb bare of trees. Anyone should be able to remove whatever trees they want off their own land. I am sure houses have been lost in bush fires because of the religious fanaticism from tree-huggers.

Where I lived in Anaheim that almost happened to us after trimming the tree on the narrow strip of grass between the sidewalk and street which we were required to maintain.  The tree in question inexplicably died a year later.

[Marco]

I saw a product like that but it took several men like half a day to install which seems to me like a good way to fall off of a roof.

Maybe some tethered drones with ridiculous amounts of lift could pull a weighted tarp even in high winds? Less dangerous than the launch system, but maybe too expensive to have your own set of drones.

[David Hess]

I saw a product like that but it took several men like half a day to install which seems to me like a good way to fall off of a roof.

Maybe some tethered drones with ridiculous amounts of lift could pull a weighted tarp even in high winds? Less dangerous than the launch system, but maybe too expensive to have your own set of drones.

It is difficult to imagine that a dedicated service would be economical because even with a helicopter or drones, they would have to service all of their clients at once.

Some people have managed to effectively fireproof their homes with proper construction, materials, and landscaping despite government interference.  California has required non-combustible roofs for a while now (20 years?) although every home I lived in there had a terribly vulnerable shake (wood shingles) roof.  Tile roofs were common even 20 years ago though at least in the more expensive and exposed areas.

[Marco]

I was imagining a system cheap enough every home owner could have his own ... you could definitely make dart launchers cheap, but it's dangerous and needs accurate setup. Not idiot proof.

Drones are a little less dangerous. If you could make the drones cheap enough you might be able to make a system a home owner can roll it out himself, then have the system self verify (dGPS) it's within predetermined parameters and follow a predetermined path to pull the tarp across?

[David Hess]

I was imagining a system cheap enough every home owner could have his own ... you could definitely make dart launchers cheap, but it's dangerous and needs accurate setup. Not idiot proof.

Drones are a little less dangerous. If you could make the drones cheap enough you might be able to make a system a home owner can roll it out himself, then have the system self verify (dGPS) it's within predetermined parameters and follow a predetermined path to pull the tarp across?

One problem I see with systems like you describe is if they are not regularly used, then they have questionable reliability when needed.  After I lost power in the aftermath of an ice storm for a week, among other things, I acquired a propane backup heater and deliberately use it during winter just to maintain readiness.