Are sprinkler systems required for timber framed houses?

[2104GJ]

Is a timber framed house, full of cellulose, or any equivalent blown insulation, more of a fire risk than a block build house?  I have seen house specs, for timber frames, that include sprinkler systems, roof and wall mounted, is this a necessity?

 

 

[Crofter]

It's not legally required, certainly on the size and type of property most self builders are dealing with.

Fire regulations are generally there to preserve lives, not buildings. So attention is paid to means-of-escape windows, and the use of temporary fire barriers (the most common being plasterboard, which can provide c.30min protection to the timber frame). On three storey buildings doors may need to have intumescent strips.

There are also regulations concerned with the spread of fire within cavities, and between properties.

[Temp]

Some but not all insurance companies treat timber framed houses as "non-standard construction". With some it depends on the outer leaf. If that's brick they consider it standard, if it's also timber they consider it non-standard.

 

I don't think there is much difference between a brick-brick and timber-brick house but personally I would be nervous of fire spread if I was living in a timber framed apartment/flat/hmo. They are meant to have appropriate fire barriers but the standard of construction used on some buildings leaves a lot to be desired (see recent stories about missing wall ties in Scottish schools for example).

 

There have been a few timber framed apartment blocks that have gone up rapidly during construction (perhaps before plaster boarding when they are more vunerable)....

 

http://www.building.co.uk/‘a-lot-of-the-guys-won’t-work-on-timber-frame-again’/3078198.article

 

 

 

 

[TerryE]

If you read the regs, then you will see that there are different rules if it is attached or shared occupancy, but for a single occupancy dwelling -- that is a conventional detached house, then the regulations make no difference.  If you think about it, there isn't a material difference if the fire is contained within the room where it originates (for example the cost common fire is a pan fire on the cooker).  On the other hand once the fire has got into the fabric of the building (e.g. into the joist space -- especially with modern eco-joists) then modern house once materially gutted will normally be condemned whatever the construction is.

 

We discussed this on another thread and the risks of dying in a road accident are roughly 20 times greater than in a house fire if you are non-smokers.  House fires are usually newsworthy, but they are in reality very infrequent.  Our passive house has no smokers inside, no open fires, no mobile space heaters, electrics to current BRegs, a decent fire alarm system and the correct immediate action measures (fire blank plus powder extinguishers) so the chances of it going up in flames are a lot less than a 1970s house with an open fire.

[AliG]

Most recent fire statistics for England, UK statistics are a year older.

 

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/532364/fire-statistics-england-1415-hosb0816.pdf

 

There were 263 fire deaths compared to 1732 road deaths on England for the last year of statistics and we spend a lot more time at home than in our cars.

 

36% of fatalities were caused by cigarettes, cigars or pipes. Another 7% were caused by cigarette lighters or matches.

 

The next highest causes of deaths were space heating appliances and candles, followed then by other electrical appliances. Considering the number of candles in use relative to electrical appliances this is extraordinary. I regularly hear warnings not to leave phones charging, but not about not using candles!

 

50% of fires were caused by cooking appliances, although only 6% of deaths.

 

So no deep fat fryer, no smoking, no candles and no space heaters (I'd guess stand alone electric or gas fires)

 

Thus 65% of all household fire related fatalities are very easily avoided.

 

If you are building a new house that meets building regs it and you're not a fan of eating fish and chips by candle light whilst smoking your pipe and toasting your feet on a single bar electric fire I wouldn't worry about it.

 

Smoke detectors should give ample warning of a fire in a house constructed to regs. Plasterboard doesn't burn that easily so it doesn't really matter what is behind it. It is interesting to note that 12% of houses don't have smoke alarms but 35% of fatalities occurred in houses without alarms. Maybe we should all make sure our alarms are working.

 

 

[TerryE]

IIRC Smoking, in-room CalorGas or equiv heaters and open fires account for something like 2/3rds of home fire fatalities.  Factor in decent smoke alarms and we are in the 1:20 ballpark.  OK maybe 1:10, but the thing to note is that you need to register a house fire and get a case number to make an insurance claim, so the stats include and fire which resulted in an insurance claim.  Maybe someone might want to compare car write-offs to house write-offs.

[ProDave]

When I had a proper job, we regularly went on fire training courses.  I am sure they said the biggest cause of house fires was Arson.  So be careful who you upset.
 

[Guest Alphonsox]

It's a house - you can always rebuild and possessions can be replaced. In the event of fire you need to ensure that the people in the dwelling get out without injury as quickly as possible. As mentioned above this is what building regs are targeting and what you need to work towards.

So  :-

- build to the exceed building regs not what you can get away with.

- Fit the best detectors you can find (we're currently fitting AICO  to our timber frame)

- Fit the best alarms you can find (I have my deaf mother living with us, not currently sure how to handle this. Maybe I should spray cold water at her ?)

- Make sure nothing impedes speedy exit night or day (child locked windows, locked doors with no keys).

- Check that you could get out of any room if the door was blocked (emergency window hammers).

- get good insurance

 

As an afterthought would you buy a timber frame house that had been comprehensively soaked with water as a result of a fire ? would you want to live in one ?

 

Edit :- The blown cellulose used for insulation is treated with fire retardant.

[AliG]

It's amazing how easy it is to find stats nowadays.

 

The stats I gave were for accidents.

 

In 2001 fires were roughly 50/50 accidental/deliberate.

 

By 2013 it was 25/75 accidental to deliberate. But for residential fires it was only 10% deliberate.

 

I agree with Alphonsox, I am much more worried about timber getting wet than catching fire and I only gave the stats for fatalities because property damage is covered by insurance and can always be fixed.

Edited October 26, 2016 by AliG

[TheMitchells]

I am sure that I read somewhere that its very hard to make blown cellulose burn as it is so tightly packed in there is no oxygen to burn. 

 

And in the recent Build It awards, I saw a product which looks really good and may be worth considering; its Automist Smartscan which is like a sprinkler system but it is triggered by heat, rather than smoke, and the spray head swivels to where ever the heat is and targets the area with a powerful jet of water.  The idea being that it only targets the danger area and the rest of the house is protected.  It is ideal for open plan living and helps compliance with Building Regs.

[Ferdinand]

I would probably fit a sprinkler system anyway, unless it was a *really* tight budget.

 

As I see it the key benefits are:

 

1 - If a fire does start the detectors in every room will likely catch it earlier than waiting for smoke to seep under doors etc, and damage will be limited to one room, not half the house plus umpteen thousand gallons of water.

2 - Therefore far less water damage too.

3 - And less need to move house for months and months.

4 - Plus more design flexibility around compartmentalisation etc.

 

There was a ridiculous statistic around that no one in the UK had ever been killed in a house with a maintained sprinkler system, but I think that may have gone to 1 a few years ago. Treat that as apocryphal until someone cites a source.

 

2 hours ago, TheMitchells said:

I am sure that I read somewhere that its very hard to make blown cellulose burn as it is so tightly packed in there is no oxygen to burn. 

 

And in the recent Build It awards, I saw a product which looks really good and may be worth considering; its Automist Smartscan which is like a sprinkler system but it is triggered by heat, rather than smoke, and the spray head swivels to where ever the heat is and targets the area with a powerful jet of water.  The idea being that it only targets the danger area and the rest of the house is protected.  It is ideal for open plan living and helps compliance with Building Regs.

 

Agreed. Melting link heat alarms at iirc approx 60C are normal for sprinkler systems.

 

I believe they were planning to make sprinkler systems mandatory in Wales on newbuilds - has that happened yet? It seemed to be partially virtue signalling since the cost-benefit analysis of the policy was well on the wrong side of the line. 

 

Ferdinand

 

Edited October 27, 2016 by Ferdinand

[jack]

2 hours ago, Ferdinand said:

There was a ridiculous statistic around that no one in the UK had ever been killed in a house with a maintained sprinkler system, but I think that may have gone to 1 a few years ago. Treat that as apocryphal until someone cites a source.

 

Might that be to do with the fact that a vanishingly small proportion of houses in the UK actually have them fitted? 

[Ferdinand]

28 minutes ago, jack said:

 

Might that be to do with the fact that a vanishingly small proportion of houses in the UK actually have them fitted? 

 

I am sure that is part of it.

 

However there are genuine benefits, and a significant minority of smoke alarms are not functional.

 

More information from the Association here:

http://www.bafsa.org.uk/sprinkler-information/domestic-residential-sprinklers.php

 

But I would agree it is a balance.

 

F

Edited October 27, 2016 by Ferdinand

[Ferdinand]

LEt's get some costs on this thread for comparison.

 

According to Mark Brinkley, a sprinkler system for a 4 bed house covering all rooms in a new build was about £2k to £3k overall or  £200 per outlet or £15-20 per sqm  in 2011, and cost of damage in a fire was 75-80% less than a smoke alarm and fire brigade system. PLus a maintenance contract. Good review article from Mark:

https://www.homebuilding.co.uk/do-homes-need-sprinklers/

 

For guestimating purposes I would call that £20 now per outlet.

 

Does anyone have any real numbers for a good quality wired smoke alarm system in a similar house, then readers can get a better picture?

 

Ferdinand

[Bitpipe]

I had a quote for a sprinkler system in our core and basement (100m2) that was about £6k plus potential extras of £1500. Main reason we considered it was to remove the need for external basement stairs. One of the upsides of a sprinkler is that it causes less water damage when suppressing a fire compared to the fire brigade, especially the (more expensive) atomising mist variety. 

 

In the end, we went for the exit option and it's made the space more usable.

 

 

[Oz07]

Who's bothered about how much damage the fire brigade do, that's what insurance is for!