BS 8511

[rjasmith]

Well I've read it all now and I have to say that it is quite a transformation from the original draft.

 

Has anyone else been able to read it yet?

 

Provided you go for a stove built and tested to BS 13240 the hearth arrangement and clearance from cabin sides don't seem too onerous. These are essentially the same as they were in the draft but it's a lot better explained and illustrated.

 

They've completely exempted small stoves having less than 0.01m³ firebox vol and less than .05m² grate area. I haven't measured my Premier stove's fire box/grate yet but I think it may meet this. Perhaps the Epping does as well. Additionally 8511 now makes all its requirements non mandatory in back cabins.

 

The only bit I still don't like is the insistence on a section of insulated chimney through the roof collar from at least 150mm below the roof lining. Then the external chimney has to be insulated as well although 8511 now acknowledges that it has to be readily removeable.

 

I really don't see the point of requiring such a short length of insulated chimney. Does it really improve the draw that much when the rest of the flue is allowed by the doc to be uninsulated?

 

If the section through the roof collar down to 150mm below the lining is intended to keep the heat of the flue away from the roof lining that might be a different matter but how hot does the very top of a stove flue pipe get anyway? The traditional steel flue pipe/cast steel collar fixed to a steel roof of enormous area would seem to me to act as a very effective heat sink and must tend to keep fairly cool.

 

Has anyone measured the temperature of their roof collar when the stove below is going at a reasonable rate of burn - I wouldn't have thought it would be very hot. I put stuff like this in my comments last April but I seem to have been ignored!

 

Can't win em all I suppose!

 

Richard

[W+T]

My god, is it just me, i ahve been reading through a few post on this thread and its battered my head, all the BS stuff sounds to be getting more and more cunfusing.

I got a BSS file ( the red one that goes through all the requirements needed ) a few yers ago to do a refit but that one never got finished, i know have a GRP cruiser which will be completed i hope this year, i guess i need to go and get an updated edition?

I was going to fit a one of these stoves, or even build my own ( very capable of doing so, will be tested a good few times before use) but not sure what to do know as neither are BS standard.

Its only 18" high and the body 8" wide.

 

wayne

[capnthommo]

Well I've read it all now and I have to say that it is quite a transformation from the original draft.

 

Has anyone else been able to read it yet?

 

Provided you go for a stove built and tested to BS 13240 the hearth arrangement and clearance from cabin sides don't seem too onerous. These are essentially the same as they were in the draft but it's a lot better explained and illustrated.

 

They've completely exempted small stoves having less than 0.01m³ firebox vol and less than .05m² grate area. I haven't measured my Premier stove's fire box/grate yet but I think it may meet this. Perhaps the Epping does as well. Additionally 8511 now makes all its requirements non mandatory in back cabins.

 

The only bit I still don't like is the insistence on a section of insulated chimney through the roof collar from at least 150mm below the roof lining. Then the external chimney has to be insulated as well although 8511 now acknowledges that it has to be readily removeable.

 

I really don't see the point of requiring such a short length of insulated chimney. Does it really improve the draw that much when the rest of the flue is allowed by the doc to be uninsulated?

 

 

If the section through the roof collar down to 150mm below the lining is intended to keep the heat of the flue away from the roof lining that might be a different matter but how hot does the very top of a stove flue pipe get anyway? The traditional steel flue pipe/cast steel collar fixed to a steel roof of enormous area would seem to me to act as a very effective heat sink and must tend to keep fairly cool.

 

Has anyone measured the temperature of their roof collar when the stove below is going at a reasonable rate of burn - I wouldn't have thought it would be very hot. I put stuff like this in my comments last April but I seem to have been ignored!

 

Can't win em all I suppose!

 

Richard

 

i havent read it yet but maybe it's to allow for the possibility of 'over firing'. if the fire should run away then maybe the insulation would provide a safety factor which wouldn't be needed in everyday use. but if the fire got out of control then perhaps so much heat could be generated that it would transfer to, and ignite the roof lining despite the 'heat sink' effect of the steel roof.

don't know really, just an idle thought.

cheers

nigel

[rjasmith]

My god, is it just me, i ahve been reading through a few post on this thread and its battered my head, all the BS stuff sounds to be getting more and more cunfusing.

I got a BSS file ( the red one that goes through all the requirements needed ) a few yers ago to do a refit but that one never got finished, i know have a GRP cruiser which will be completed i hope this year, i guess i need to go and get an updated edition?

I was going to fit a one of these stoves, or even build my own ( very capable of doing so, will be tested a good few times before use) but not sure what to do know as neither are BS standard.

 

Its only 18" high and the body 8" wide.

 

wayne

 

Yes it is getting a bit complicated I suppose but don't forget that the Boat Safety Scheme (BSS) is not the same thing as a British Standard (BS). At the moment, if you've got a current BSS guide (the red(ish) book dated Aug 2005) it hasn't changed just because BS 8511 has come out. That's not to say that it won't in the future perhaps but the BSS team have told me that there are unlikely to be any major changes to their guide as a result of BS 8511. Also they say they don't plan to make any until BS 8511 has "bedded down in the boat industry" (ie not for quite a long time I imagine!)

 

A key exemption in BS 8511 is made for very small stoves as I said above. I think your picture is of a "Pipsqueak" stove isn't it? Have you tried measuring its firebox and grate sizes - it might be exempt as I believe the usual back cabin stoves are (still haven't measured my Premier!!).

 

However, my feeling about BS 8511 (apart from the dreaded insulated flue stuff!) is that it is now a pretty clear document and gives some good guidance on how to do a safe job.

 

Richard

[rjasmith]

i havent read it yet but maybe it's to allow for the possibility of 'over firing'. if the fire should run away then maybe the insulation would provide a safety factor which wouldn't be needed in everyday use. but if the fire got out of control then perhaps so much heat could be generated that it would transfer to, and ignite the roof lining despite the 'heat sink' effect of the steel roof.

don't know really, just an idle thought.

cheers

nigel

 

That's certainly a good point and I agree there needs to be a consideration for accidental overfiring.

 

I certainly don't plan on having no clearance at the top of the flue from combustible stuff and I masked off a substantial area of steel roof so that it was kept clear of sprayfoam round the bottom of the collar (spray foam is only fire retardant not fire proof). This area will have a bit of rockwool in it instead and the wood lining will be similarly kept away and replaced by an area of calcium silicate board. I've decided to use Super Isol following a few exchanges in other threads - it has a really low thermal conductivity.

 

I think the next step will be to do a temporary rig of the stove and conventional flue/chimney (boat is still unlined as yet), fire it up and measure some temperatures. This is only what they do to pass a stove to BS 13240 after all.

 

Will be interesting to see what happens!

 

Richard

[W+T]

Yes it is getting a bit complicated I suppose but don't forget that the Boat Safety Scheme (BSS) is not the same thing as a British Standard (BS). At the moment, if you've got a current BSS guide (the red(ish) book dated Aug 2005) it hasn't changed just because BS 8511 has come out. That's not to say that it won't in the future perhaps but the BSS team have told me that there are unlikely to be any major changes to their guide as a result of BS 8511. Also they say they don't plan to make any until BS 8511 has "bedded down in the boat industry" (ie not for quite a long time I imagine!)

 

A key exemption in BS 8511 is made for very small stoves as I said above. I think your picture is of a "Pipsqueak" stove isn't it? Have you tried measuring its firebox and grate sizes - it might be exempt as I believe the usual back cabin stoves are (still haven't measured my Premier!!).

 

However, my feeling about BS 8511 (apart from the dreaded insulated flue stuff!) is that it is now a pretty clear document and gives some good guidance on how to do a safe job.

 

Richard

 

 

Hi Richard, yes thats a pipsqueak, very small, the trouble is i cant measure the ares as i havnt got one yet, also its difficult to before i get one as nobody near me sells them to get the measurements before i do. ( i a in the process of building one, same size, if it goes well i mte use this on the boat.)

Hope to have it fitted out within six months so i will be ok with new legislations when they do come, in they do.

Thanks for that info Richard.

 

Wayne

[rjasmith]

Hi Richard, yes thats a pipsqueak, very small, the trouble is i cant measure the ares as i havnt got one yet, also its difficult to before i get one as nobody near me sells them to get the measurements before i do. ( i a in the process of building one, same size, if it goes well i mte use this on the boat.)

Hope to have it fitted out within six months so i will be ok with new legislations when they do come, in they do.

Thanks for that info Richard.

 

Wayne

 

Wayne,

 

I'm sure the Pipsqueak (or a stove made to be the same size) would be exempt.

 

I measured the actual firebox dimensions of my Premier back cabin stove yesterday. The firebox is approx 220 x 100 x 150mm so this makes the firebox vol 0.0033m³ and the grate area 0.022m². These are well within the limits set in the new version of BS 8511 of less than 0.01m³ and 0.05m² for exempt small stoves.

 

The Epping must have similar dimensions so it will be exempt as well I imagine.

 

Looking at websites giving the outside dimensions of the Pipsqueak it seems it is 440 high by 200 wide by 180 deep. The fire box will obviously be smaller in width/depth and looking at the picture it can only be approx half the overall height as the stove has tall legs and an ashbox that account for the bottom half.

 

So using 220 x 200 x 180 you get a vol of 0.008m³ and an area of 0.036m². So it will be exempt also!

 

Having said all that I strongly recommend you take a look at BS 8511 because it's now much clearer and more practical than it was and gives some good guidance. The trouble is getting hold of a copy without having to pay the £142! Perhaps a trip to the local library where you'll be able to read it (after they've ordered in a copy I expect)? Alternatively if you or friends work somewhere where the firm is a BSi member, something could be arranged!!!?

 

Richard

[WotEver]

Tony, Don't buy that one whatever you do!!!

 

That's the draft version issued in Feb 2009 and is a pile of poo by comparison with the new issue. Still haven't read all the new one yet but so far it seems really quite good - what a surprise!

 

Richard

Thanks for the advice

[luctor et emergo]

As an aside, why is it so expensive to obtain a copy? Do they really expect people to shell out that much, on top of a stove etc, to find out what the new guidelines are?

And do I understand it correctly that these are just 'guidelines', and not binding rules?

[rjasmith]

As an aside, why is it so expensive to obtain a copy? Do they really expect people to shell out that much, on top of a stove etc, to find out what the new guidelines are?

And do I understand it correctly that these are just 'guidelines', and not binding rules?

 

I'm afraid ALL British Standards are priced at around £150 each or half that if you're a BSi member (paying an annual fee!).

 

It's the way of the world it seems - BSi exists to produce standards for industry and commerce and not for DIY'ers unfortunately!

 

If you wanted to build a new boat to comply with the RCD (as I'm trying to do) you need access to about 26 different BS standards! To buy them all individually from BSi would therefore cost nearly £4000!!!

 

Luckily all libraries will let you read them for free either on a PC at the library, on paper at the library once you've given them time to get copies in, or as some county libraries do, allow library members access to BSOL via their website from home.

 

Ask your local library what they can do.

 

Yes - BS 8511 is a Code of Practice and defines what BSi's drafting committee believe are safe practices for people to follow rather than being absolutely mandatory. There are statements to this effect at the beginning of it. As I said earlier I have emails from the Boat Safety Scheme chaps saying that they are unlikely to change much in their guide as a result of BS 8511 and not for a while yet. The problem is more likely to be when an insurance company uses BS 8511 to defend a claim for a fire incident!!

 

Richard

[luctor et emergo]

I'm afraid ALL British Standards are priced at around £150 each or half that if you're a BSi member (paying an annual fee!).

 

It's the way of the world it seems - BSi exists to produce standards for industry and commerce and not for DIY'ers unfortunately!

 

If you wanted to build a new boat to comply with the RCD (as I'm trying to do) you need access to about 26 different BS standards! To buy them all individually from BSi would therefore cost nearly £4000!!!

 

Luckily all libraries will let you read them for free either on a PC at the library, on paper at the library once you've given them time to get copies in, or as some county libraries do, allow library members access to BSOL via their website from home.

 

Ask your local library what they can do.

 

Yes - BS 8511 is a Code of Practice and defines what BSi's drafting committee believe are safe practices for people to follow rather than being absolutely mandatory. There are statements to this effect at the beginning of it. As I said earlier I have emails from the Boat Safety Scheme chaps saying that they are unlikely to change much in their guide as a result of BS 8511 and not for a while yet. The problem is more likely to be when an insurance company uses BS 8511 to defend a claim for a fire incident!!

Richard

 

But if it is a Code of Practise rather than a requirement, can the insurance company use it to decline a claim, anymore than they can now (I presume that they look closely at the manufacterer's instalation guidelines, to see if the stove was installed according to those?)? If that is the case, would that not make it a 'requirement' defacto, because if you don't follow the BS 8511 guidelines, your insurance could effectively be nul and void?