Smoke Alarm saved our lives last night...

Re: Smoke Alarm saved our lives last night.......

gald to hear everything went well...
and everyones safe and sound....

Re: Smoke Alarm saved our lives last night.......

While you sound very grateful and are praising the detector, Im wondering why it took so long to go off. You said the rubbish bin went up, then the computer. Your son saw so much smoke by the time he awoke he didnt know where he was.

Im sorry but this is far from a good result (yes it could have been much worse). The detector should have gone off well before this point. The problem is that people install cheap ionisation detectors, which go off up to 30mins after photo-electric ones.

A spark cannot cause a bin full of paper to fully ignite in a few seconds. There would have been a smoldering fire for probably 5 mins or so, until enough heat was generated to ignite the paper. The amount of smoke after 1 or 2 mins should have been enough to set off a detector.

Re: Smoke Alarm saved our lives last night.......

you sensing a conspiracy here money tree

(ps... just joking.... sorry, couldnt resist... ... )

Re: Smoke Alarm saved our lives last night.......

money tree said:

While you sound very grateful and are praising the detector, Im wondering why it took so long to go off. You said the rubbish bin went up, then the computer. Your son saw so much smoke by the time he awoke he didnt know where he was.

Im sorry but this is far from a good result (yes it could have been much worse). The detector should have gone off well before this point. The problem is that people install cheap ionisation detectors, which go off up to 30mins after photo-electric ones.

A spark cannot cause a bin full of paper to fully ignite in a few seconds. There would have been a smoldering fire for probably 5 mins or so, until enough heat was generated to ignite the paper. The amount of smoke after 1 or 2 mins should have been enough to set off a detector.

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Money,oh please lets not start a conspiracy ,expensive versus cheap,blame Rafa he started it :

But seriously,Prospector said that the sensors were placed on top of the boys bed,instantly I got a mental picture of her wanting to do the right thing for her children,I agree with you though the sensors were too far away from the source of the fire,nothing to do with how expensive the sensors were.they should have been placed near where the fire was likely to start ,so that as the smoke started to rise the alarm would go off.We have those cheap 10dollars sensors,I can tell you that when we burn toast they always go off.And even when we become distracted and can`t smell the burning toast the heat from the toast will set it off.

I should point out we use our grill for toasting.

Re: Smoke Alarm saved our lives last night.......

It's important to keep these alarms clean and free of dust etc for them to work properly. And NEVER paint over them as this will render them basically useless.

There are some more expensive models on the market which incorporate an in-built light which activates automatically when the alarm sounds. Depending on where the alarm is located, this could be a helpful idea. They are battery powered with separate 9 volt batteries for the alarm and the light (so that the light can't flatten the alarm battery). Not sure of the price but I think it's around $40 each?

Off the topic of alarms but still relevant to fire safety. If you have a wood heater, pot belly stove, open fire etc then please get the chimney / flue checked and cleaned regularly. Once the soot builds up, it is practically as flammable as oil and the flames rush straight up the chimney once it starts to burn. If it's in poor condition (metal ones rust eventually and brickwork cracks - stainless steel is the safer option but still doesn't last forever) then the flames will be in the roof space before you know it - there goes the house.

Another big risk to look out for is old black rubber electrical wiring. This is way past its used by date and a real fire hazard. It's common in houses from the 1950's or earlier. If you find it, DON'T move it in any way as it is likely so fragile due to age that moving it could cause it to immediately fail. But it WILL fail sooner or later, possibly causing a fire, even if not moved so get a qualified electrician to replace it - not cheap but worthwhile IMO.

Re: Smoke Alarm saved our lives last night.......

money tree said:

While you sound very grateful and are praising the detector, Im wondering why it took so long to go off. You said the rubbish bin went up, then the computer. Your son saw so much smoke by the time he awoke he didnt know where he was.

Im sorry but this is far from a good result (yes it could have been much worse). The detector should have gone off well before this point. The problem is that people install cheap ionisation detectors, which go off up to 30mins after photo-electric ones.

A spark cannot cause a bin full of paper to fully ignite in a few seconds. There would have been a smoldering fire for probably 5 mins or so, until enough heat was generated to ignite the paper. The amount of smoke after 1 or 2 mins should have been enough to set off a detector.

Click to expand...

I think it probably did go off fairly quickly, but we are talking about a teenager here who probably, well, sleeps like the dead may not be quite the appropriate term, but you get my drift : He sleeps through thunderstorms that cause partner and I to jump - we are on the ground floor and he sleeps close to the roof! I think the alarm would need to be on his pillow for him to wake up straight away!

Re: Smoke Alarm saved our lives last night.......

visual said:

Money,oh please lets not start a conspiracy ,expensive versus cheap,blame Rafa he started it :

But seriously,Prospector said that the sensors were placed on top of the boys bed,instantly I got a mental picture of her wanting to do the right thing for her children,I agree with you though the sensors were too far away from the source of the fire,nothing to do with how expensive the sensors were.they should have been placed near where the fire was likely to start ,so that as the smoke started to rise the alarm would go off.We have those cheap 10dollars sensors,I can tell you that when we burn toast they always go off.And even when we become distracted and can`t smell the burning toast the heat from the toast will set it off.

I should point out we use our grill for toasting.

Click to expand...

Actually, the sensor was maybe 2 metres from where the fire started. Just wondering, given that the fire started from an electrical appliance (or maybe even the power point) the only way you could have a fire detector "near where the fire was likely to start" would be to have them over EVERY appliance in the house. Including radios, TV's, washing machines, dishwashers, dryers, lamps, computers, telephones - get my drift!

Re: Smoke Alarm saved our lives last night.......

Prospector said:

Actually, the sensor was maybe 2 metres from where the fire started. Just wondering, given that the fire started from an electrical appliance (or maybe even the power point) the only way you could have a fire detector "near where the fire was likely to start" would be to have them over EVERY appliance in the house. Including radios, TV's, washing machines, dishwashers, dryers, lamps, computers, telephones - get my drift!

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Prospector,unless your children smoke you should``nt need a sensor over their bed,
the sensor should be placed not directly over appliances but so that as the smoke travels the sensor goes off,you dont want to give the fire time to develop,you want the smoke to set it off.
Example in our kitchen we have two sensors one a bit of a distance from the stove,the other one at the back of the kitchen near our television,one in the corridor so God forbid a fire starts in the kids room the smoke will set it off.
Prospector we don`t live in a 6oohundred thousands dollar house so I suppose thats the difference,

Re: Smoke Alarm saved our lives last night.......

Prospector said:

Actually, the sensor was maybe 2 metres from where the fire started. Just wondering, given that the fire started from an electrical appliance (or maybe even the power point) the only way you could have a fire detector "near where the fire was likely to start" would be to have them over EVERY appliance in the house. Including radios, TV's, washing machines, dishwashers, dryers, lamps, computers, telephones - get my drift!

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Ionisation type smoke alarm takes ages to activate if smoke builds up gradually.

Similar to slowly boiling frog.
Minute incremental increases in smoke concentration fool the smoke alarm.
That’s why photoelectric smoke alarm wins every time.

Re: Smoke Alarm saved our lives last night.......

visual said:

Prospector we don`t live in a 6oohundred thousands dollar house so I suppose thats the difference,

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Hey Visual, I wish we did! The $600K came from the combined building replacement, contents replacement and costs of demolition! Looking at things now, the average building of a double brick 4 bedroom house costs around $250 - $300K to build, contents well over $150K by the time you include everything you own, - Clothing and personal effects, curtains, carpets, PC's, clothing, cameras, lounges, beds and bed linen etc etc! Curtains, TV's, even the cost of things like telephone reconnnections, new sewerage trenches have to be dug and so on. Security systems. Insulation. Airconditioning. Council approvals. Fences. Paving. Pergolas. Sheds. Equipment in sheds like lawnmowers, power tools. Then add several thousand for the cost of demolition and transport of the remains of your house.

You would be surprised how quickly the $$$ get gobbled up. And I think maybe some trades also take advantage of Insurance claims too, just a thought!

And to the others re types of Alarms - am having a look at those photoelectric devices too - are they available from the usual hardware shops? I am even more paranoid than I used to be!

Re: Smoke Alarm saved our lives last night.......

Happy said:

Ionisation type smoke alarm takes ages to activate if smoke builds up gradually.

Similar to slowly boiling frog.
Minute incremental increases in smoke concentration fool the smoke alarm.
That’s why photoelectric smoke alarm wins every time.

Click to expand...

Ionisation - best for fast starting fires. For example, when the toaster or pan on the stove catches fire or an electrical appliances suffers a major short circuit.

Photoelectric - best for slow starting fires such as what happened in this case.

If you want the best protection then a combination of both is the way to go IMO. Ionisation should generally work pretty well in the kitchen, for example, but photoelectric is a better option for some other parts of the house.

There are some mains powered alarms where both types can be interconnected together - ALL the alarms will sound when ANY of them detects smoke. You can have a "silence" button which switches them off for about 5 minutes (they turn back on automatically) for when the toast burns etc. You'll need professional installation however since they are mains powered (rechargeable battery backup) and need to be wired directly into the mains supply. Not cheap but it ought to work.

I've seen someone smoke a cigarette standing directly under a smoke detector without the alarm sounding so they're not foolproof. And yet a propane blowtorch (which makes no visible smoke) set it off straight away. The slow burning cigarette versus the hot gas flame - the latter triggers the ionisation type far more effectively but may not trigger a photoelectric alarm at all. So ideally you want both.

Re: Smoke Alarm saved our lives last night.......

Prospector said:

And to the others re types of Alarms - am having a look at those photoelectric devices too - are they available from the usual hardware shops? I am even more paranoid than I used to be!

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I don`t know what type you should buy,but looking at ours,it complies with AS 3786 1993,so thats a good start make sure it meets with the Australian standard.
Ours also contains radioactive material I don`t know what that means.

Your insurance company will probably insist that you now meet their standard seeing that you house almost became a claim!So maybe you are worring for nothing.

Re: Smoke Alarm saved our lives last night.......

visual said:

I don`t know what type you should buy,but looking at ours,it complies with AS 3786 1993,so thats a good start make sure it meets with the Australian standard.
Ours also contains radioactive material I don`t know what that means.

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Having radioactive material in it makes it an ionization detector. The AS # probably stipulates this too - I am not sure if there is more than one standard but I would think so,
John

Re: Smoke Alarm saved our lives last night.......

A plastic that transforms itself into a firepoof ceramic...lights up the Fire Protection market: http://www.abc.net.au/ra/innovations/stories/s1714166.htm