Storage of gas bottles

[Minstrel]

A recent fire in a garage attached to a house resulted in 250 people being evacuated due to the oxy-acetylene tanks stored in the garage (used for welding car chassis together).

 

This made me wonder whether our propane gas bottles are safe stored in our garage. Would the shed be any safer?

 

The most important thing is - should we inform our insurers that gas bottles are stored on the premises?

[Derek Uzzell]

Propane gas-canisters should NOT be stored (or installed) in an enclosed space within, or attached to, a house. A limited number of butane cylinders should be OK (if you've got nowhere else to put them), but definitely not propane containers.

 

It would be preferable if you stored your gas bottles under cover, but fully open to the air, but, failing that, they'd be better kept in a well-ventilated shed well away from domestic property than in your garage.

 

Calor's advice is on:

 

http://www.calor.co.uk/customer-services/lpg-safety/lpg-cylinder-storage/cylinder-storage-information/

 

Regarding your last question, you'd need to contact your own insurer about what they require of you. If you were not following Calor's good advice (eg. your propane bottles were in your garage and they blew your house sky-high), I would expect an insurer to be reluctant to pay for the damage.

[tonyg3nwl]

Hi, Reading the second item, this suggests that it would not be possible to store your bottles in your motorhome in front of your property in the secure locker provided, or am missing something?

What if the motorhome were stored in your garage to comply with some insurers requirement regarding security.

 

tonyg3nwl

[lennyhb]

Oh dear I'd better move some bottles I have collection accumulated over the years stored in my attached garage.

 

As mentioned by Tony what about the ones in my Motorhome about 6 foot from where I'm sitting now in my office.

 

 

 

[Derek Uzzell]

tonyg3nwl - 2010-12-09 8:39 AM

 

Hi, Reading the second item, this suggests that it would not be possible to store your bottles in your motorhome in front of your property in the secure locker provided, or am missing something?

What if the motorhome were stored in your garage to comply with some insurers requirement regarding security.

 

tonyg3nwl

 

Obviously it IS "possible to store your bottles in your motorhome in front of your property in the secure locker provided". I and (I'm sure) thousands of other motorcaravanners do this. The question is "Will your insurer object to you doing this?"

 

Personally, I don't believe insurers will object to this practice, but I've never asked mine to confirm whether or not that belief is valid.

 

Realistically, I can't imagine why an insurer should demand that a motorhome/caravan be stored in a domestic garage, but (just for the sake of argument) this were the case, then I presume the insurer would insist that gas-bottles be removed from the vehicle and stored elsewhere.

 

If motorcaravanners independently choose to store their vehicles in a domestic garage for security/protection reasons (and quite a few people do), then they'll need to consider the potential risks of leaving the gas-bottles in situ within the motorhome and possible insurance-related implications.

 

Although it's perfectly reasonable to raise questions like this on forums, the only way to be certain of an insurer's stance on such matters is to seek written advice from the insurer.

[Brian Kirby]

tonyg3nwl - 2010-12-09 8:39 AM Hi, Reading the second item, this suggests that it would not be possible to store your bottles in your motorhome in front of your property in the secure locker provided, or am missing something? What if the motorhome were stored in your garage to comply with some insurers requirement regarding security. tonyg3nwl

The gas cylinders in a motorhome gas locker are being stored in an enclosure purpose designed to store up to the designated number of cylinders.  The enclosure is vented in accordance with the relevant regulations.  What is to worry about?

If the motorhome were kept in a garage with the cylinders on board I can't see what changes.  Garages are (should be!  :-)) ventilated at high and low level, to allow petrol fumes to escape in the event of a fuel leak.  Petrol fumes, like LPG, are heavier than air, so if the ventilation is deemed adequate in the event of a fuel leak, why not for an LPG leak?  Conjecture on my part, admittedly, but reasonable, IMO.  Anyone know different?

[Wingpete]

LPG vapours are heavier than air, and therefore must not be stored below ground level in case of leaks accumulating.

 

Well venitlated storage is acceptable.

Bear in mind, many households use LPG portable heaters for sound reasons of convenience and costs. There is no restriction on LPG cylinders being so used, but care as ever, needs application when changing a cylinder.

 

The incident that initiated this debate was most lilkely attributable to the use of acetylene gas cylinders.

They are notorious for causing violent explosions when involved in fires.

The acetylene gas is low pressure and only vapourises at ambiente temperatures, and is controlled in the amount of flow needed, by specail gas control valves, that allow it to mix with oxygen fed from a separate cylinder, so giving power to a cutting or welding torch.

When the operative fails to make safe use of the acetylene valves, they usually bolt to safety and call fire brigade to clear up their mess.

Believe me, you need to take good cover for safety sake, until the cylinder is cooled sufficinetly after 24 hrs immersed in water, or until if explodes, violently

 

 

 

[chas]

I cant see any greater risk having spare propane gas cylinders with the valves shut in a garage or stored near your home than a car with possible 20 gallons of petrol in its tank, with fuel lines mounted running around its engine.

 

Sounds a bit like yer elf an safety. For goodness sake lets just act in a responsible way, and not compare this with a garage not properly maintaining its oxy-acetylene tanks correctly.

[Minstrel]

Thanks! I knew you'd all come up with something.

 

We have a spare propane bottle as we inherited an old one and exchanged it. We keep one large one mainly for winter use and when it's finished tuck it away in the garage, but of course, meanwhile a full 6kg bottle sits in the back of the garage.

 

We also have a butane bottle kept in the garage attached to a camping cooker, very useful for family days out on Dartmoor to cook beans and sausages.

 

We also have a patio gas bottle (propane and butane mix) sitting within 4 metres of the back door attached to the BBQ.

 

I guess the shed at the top of the garden will have to be home to the bottles now, that's 12 metres from the back door, but not as secure as the garage.

 

 

[747]

A full bottle of gas will be dangerous in the case of a house fire. An 'empty' bottle could be catastrophic.

 

Explosions vary on the mixture of gas to air. If you have a bottle with a very small amount of gas in, that could be the optimum mix for a violent explosion.

 

We were taught that the most explosive mixture of Methane in a coalmine was between 5.5% and 9.25% Methane to air. The miners safety lamp showed an increased blue halo of flame at 1.25%. At 2.5%, all (flameproof) electrical equipment must be switched off and all men to leave the area.

 

Due to a (typical) mistake while working on a refinery overseas, I saw the effect of an explosion of a very small amount of gas/air mix. It was more like a 'pop' than a bang and occurred when a welder struck his arc. It took all of the skin off his face. We were close by and unharmed and were able to sort him out as he was in a bit of a state.

 

A bit of respect around gas is a good thing.

[Minstrel]

Further to my last posting, I have now read all the info from Calor and there seems to be no problem with bottles stored outside and near a property but in general I imagine these would be for heating a building.

 

We thought our garage ideal to store gas bottles as it is half underground and is always cool. It has no window, but there is good ventilation at the bottom of the door. Like many people we have a freezer in there also.

 

I wouldn't like to be at the farm where our motorhome lives if there was any kind of fire as there are over 200 caravans and motorhomes.

 

[Brian Kirby]

Minstrel - 2010-12-09 5:30 PM ..........We thought our garage ideal to store gas bottles as it is half underground and is always cool. It has no window, but there is good ventilation at the bottom of the door. Like many people we have a freezer in there also. ..........

Do you really mean your garage is "half underground", which I take to mean that the whole of the garage floor is lower than the surrounding ground, and you drive down into it.  If it is, a) I am surprised it was allowed to be built (Building Regs etc), and b) unless it has properly specified, designed, installed and maintained artificial scavange ventilation, remove all gas cylinders from it pronto!  Otherwise, if gas were to leak it would simply accumulate below the lowest point of natural ventilation so, when the freezer next switched on, or the car was started, sayonara garage, Minstrel, and all!  :-)

[Brian Kirby]

747 - 2010-12-09 5:15 PM A full bottle of gas will be dangerous in the case of a house fire. An 'empty' bottle could be catastrophic. Explosions vary on the mixture of gas to air. ............

I'm not sure this is the risk, Jim.  If the gas is in the cylinder, and there is no leak, there is no question of a gas/air mixture being created, so no explosion risk. 

The greater risk in a fire is of a pressure burst, and that is far more likely if the cylinder is full, or nearly so, than empty.  Simply, the cylinder is heated by the fire, the liquid gas expands in the heat, the headspace in the cylinder is lost, and the resulting pressure ruptures the cylinder - usually, it seems, around its base.  The result is an impressive fireball at ground level, and a steel cylinder heading skywards at a rate of knots!

Some years back several sailed up past me, on the tenth floor of an office block, during a fire in a nearby builders' yard.  That's how I know!  Oh yes, and that which goes up, inevitably comes down.  And they did!  Nasty!

[Minstrel]

Brian

 

Yes, the garage is half underground with the drive sloping upwards to it. To give you more idea we have 12 steps (2 bricks and a paving slab high) from the drive up to the house. It keeps us fit (with the tennis and badminton) and we have lovely views eastwards towards Honiton. I can sit in my armchair in the lounge and see the planes coming in to Exeter Airport!

[Brian Kirby]

Hello Heather

If the drive slopes up to the garage it surely vents at the garage door?  To be clear, if you drive out of the garage, you drive downhill?  If so, the gas will leave by the same route.  :-) 

My query was if the drive sloped down to the garage, when it would truly be half buried, and there would be a danger of fumes/gas accumulating.

[colin]

A couple of points.

An integral garage should! have fireproofing between house and garage, will not stop the fire spreading but will slow it down.

As for acetylene bottles, fire service get very H&S over them which would be why 250 people got evacuated.

 

But here's a little story to tell you of incident that happened in Luton couple of years back.

 

Family drove there car into garage, as driver switched off engine a electric fault developed. This set fire to car and deadlocked doors! Luckily a nabour was walking past and he broke windows and helped family out of car, BUT, before fire service could get to scene the house burnt down, although it was 'new' the builders had not complied with regs and no fire stopping was applied.

[Dave Newell]

"The greater risk in a fire is of a pressure burst, and that is far more likely if the cylinder is full, or nearly so, than empty. Simply, the cylinder is heated by the fire, the liquid gas expands in the heat, the headspace in the cylinder is lost, and the resulting pressure ruptures the cylinder - usually, it seems, around its base. The result is an impressive fireball at ground level, and a steel cylinder heading skywards at a rate of knots!"

 

I believe the technical term is a "BLEVE" (pronounced BLEVEE). This stands for Boiling Liquid Expanding Vapour Explosion. Essentially what happens is that initially the external fire provides the heat to expand the liquid gas and increase the internal pressure. when the cylinder ruptures the liquified gas escapes and instantly boils turning to gas which then combusts and dramatically increases the heat quotient of the fire increasing the expansion of the liquified gas and turning it into a self aggravating fireball which almost nothing can extinguish short of total exclusion of oxygen which is almost impossible to acchieve.

 

In short it is an event you don't want to be invited to!

 

On the insurance point, my business insurance specifically excludes gas cylinders from being stored in the workshop but is quite happy about the gas bottle stored inside the motorhome or any other motorhome stored in the workshop overnight :-S .

 

Simplest answer with insurance is if in doubt ask your insurers surely?

 

D.

[art338]

As an interest acetylene gas in a confined space is categorised as being 'explosive' between 2% and 92%.

 

art

[Minstrel]

Had a lovely evening out with family, good meal etc. Some discussion of this post. My son is with the fire and rescue service. Apparently oxy acetylene bottles need to be cooled for 3 or 4 days when they have heated due to a fire as they can be cool to the touch and then spontaneously start to reheat themselves. That's just for interest as we are talking propane and butane.

 

Gas bottles are commonly used indoors eg in France to fuel cookers. The general opinion was that it is reasonable to store gas bottles in a garage. Another point was that one should be able to "enjoy one's property"- this being a term in law I believe.

 

Goodnight all.

[Derek Uzzell]

Minstrel - 2010-12-10 12:02 AM

 

...Gas bottles are commonly used indoors eg in France to fuel cookers. The general opinion was that it is reasonable to store gas bottles in a garage...

 

It's the norm in countries where mains gas supplies are restricted to large urban areas to employ bottled gas (eg. Spain). But, if the bottles are to be used inside a property for domestic purposes (cooking, room-heatings, etc), the gas involved will be (or should be) butane not propane. I refer you to the gas section of the following webpage. You'll note the advice relating to propane bulk tanks and bottles indicates that these should be sited away from the house.

 

http://www.spanishpropertyco.com/Electricity,%20gas,%20water.html

 

I just don't understand why there should be doubt over what's best practice in this instance. Just GOOGLE and you'll find plenty of information on the subject of gas storage and more than enough horror stories.

 

Calor's instructions regarding safe usage of butane and propane is straightforward enough:

 

http://www.calor.co.uk/customer-services/lpg-safety/using-calor-gas-safely/using-butane-safely/

 

http://www.calor.co.uk/customer-services/lpg-safety/using-calor-gas-safely/using-propane-safely/

 

You originally asked whether your propane gas bottles were safe stored in your garage (presumably an'attached' garage), or would storing them in your shed be safer.

 

The simple answer is that having any gas bottles in a house is potentially unsafe, but propane bottles (because of the nature of the gas) are potentially more dangerous than butane ones. If you've got a storage facility away from your house (eg. a garden shed), it would plainly be wiser to store your bottles there.

 

Brian Kirby's professional background allows him to comment expertly on buiding construction. But the reality is that many garages attached to houses are not well ventilated and, where there's a door between house and garage, there's certainly no guarantee that this will be suitably fire resistant or that people will keep it closed.

 

My own garage is attached to (but not integrated into) my house. It links to the house though the garage's and adjacent car-port's shared roof-space and it contains an oil-fired central heating boiler and a domestic freezer. Ventilation is limited to the gaps around the garage's lift-up metal door.

 

I'd assess the risk of serious damage resulting from a fuel leak from a diesel-engined car stored in my garage as fairly low. I'd assess the risk of serious damage resulting from a fuel leak from a petrol-engined car stored in my garage as significantly higher. I have no trouble imagining the catastrophic potential of a garage full of propane gas (or butane for that matter).

 

My spare gas bottles are stored away from my house in my garden shed. The garage is intended for housing the car, but not for storing gas bottles. I can put the car in the garage, but not in the shed. I could put the bottles in the garage, but I can put them in the shed. As it's indisputable that there's a higher risk storing the gas bottles in the garage than in the shed, I store them in the shed. Surely this is just common sense?

 

Plainly, if a motorcaravanner has nowhere to store their spare gas bottles except for their garage, then that's where they'll have to go. And, if their motorhome (complete with gas bottles) has to be stored in their garage, then that's where it will have to be stored. In such cases, if a motorcaravanner thinks those practices might possibly present insurance-related problems, they can either do nothing or ask their insurer for advice. Isn't that just common sense too?

[Brian Kirby]

Derek Uzzell - 2010-12-10 9:07 AM ................. Brian Kirby's professional background allows him to comment expertly on buiding construction. But the reality is that many garages attached to houses are not well ventilated and, where there's a door between house and garage, there's certainly no guarantee that this will be suitably fire resistant or that people will keep it closed. My own garage is attached to (but not integrated into) my house. It links to the house though the garage's and adjacent car-port's shared roof-space and it contains an oil-fired central heating boiler and a domestic freezer. Ventilation is limited to the gaps around the garage's lift-up metal door. I'd assess the risk of serious damage resulting from a fuel leak from a diesel-engined car stored in my garage as fairly low. I'd assess the risk of serious damage resulting from a fuel leak from a petrol-engined car stored in my garage as significantly higher. I have no trouble imagining the catastrophic potential of a garage full of propane gas (or butane for that matter). My spare gas bottles are stored away from my house in my garden shed. The garage is intended for housing the car, but not for storing gas bottles. I can put the car in the garage, but not in the shed. I could put the bottles in the garage, but I can put them in the shed. As it's indisputable that there's a higher risk storing the gas bottles in the garage than in the shed, I store them in the shed. Surely this is just common sense? .................

Cylinders in shed instead of in garage?  Where other means of combustion and/or combustibles share the garage, yes.  If the above is true, and the garage is integrated with the house, definitely. 

However, if the garage is free-standing away from the house, and does not have means of combustion or combustibles stored in it: it really is no more than a brick (presumably) shed and presents no greater risk.  Between these extremes, careful judgement is required, and a slab of common sense, erring on the side of safety.

To paraphrase the Building Regs requirement for a garage integrated into a house, or adjoining a house, and having a communicating door between house and garage.  The construction is to provide a 30 minutes fire resisting compartment.  That is to say wherever the garage adjoins or abuts the house, the wall, floor or ceiling of the garage shall resist the spread of fire for at least 30 minutes without loss of structural integrity.  Any openings between house and garage, including pipe, cable, drainage, or flue, openings, to be fire stopped to 30 minutes standard.  Any door between garage and house to have fire resistance of 30 minutes (integrity) with 30 minutes smoke and fume resistance, and be self-closing.  The smoke and fume resistance requirement means the door must have a frame incorporating intumescent seals, including at the threshold.  Such doors are supplied as "sets" complete with frame and threshold.  They must be correctly installed with complete fire and fume stopping all around the frame, and close gap free (that is to say the door must not be misaligned in the frame, or warped).  The garage floor must fall by 100mm from back to front, to disperse any fuel spill through the garage door or, if the floor is laid flat, there must be a 100mm step up into the house at the threshold of the intercommunicating door.

It may be instructive to look at your garage if it fits this model, especially if you store flammable material in it and/or have a boiler in it.  Older buildings may not meet the current standard, though will not be much behind if the garage was originally built as a garage.  If it was built as a waggon hovel, expect trouble!  :-D

Derek is quite right when he says doors may have been changed for non-compliant versions, or closers removed, and of course bits of DIY over the years may have left a few illicit holes here and there.  Since the garage is an unheated and comparatively well ventilated space, it would make sense to ensure it is effectively insulated from the house and that openings are sealed to prevent draughts.  Just use a purpose made fire stopping material, or a known non-combustible material, for the job!

[Minstrel]

In my case the garage is completely separate from the house, the floor being at least 3 metres lower than the floor level of the house.

 

Bearing in mind all the very helpful stuff people have written I think that probably the gas bottles are safe enough in the garage, but as Chris's scooter lives in there and a freezer, perhaps we should keep gas bottles in the shed at the top of the garden.