Fireboard

[Fuel__2001]

I used skamotec 225 which comes in 25mm thickness and you can paint on top rather than going down the traditional route of tiling - its really easy to work with and get a great modern look.

 

Also, hardibacker board from Topps Tiles which I used to create the air gap, as the boards are 12mm

 

I cant over emphasise the importance of an air gap - when i took down the previous stove installation as we moved the stove, i found out just how dangerous the installation was and how lucky we were. The wood behind the tiles was burnt and scorched as it had no airgap between the tiles and wood.

 

This time I completed the installation and used soliftec as a guide. The stove is much closer to the fire surround than the previous installation, but due to the airgap the wood behind the skamotec is stone cold to the touch.

 

Much safer and happier

[Dave Payne]

Well, I guess I was after doing things safely on a budget, and perhaps the two things are not compatible, or not entirely!

I've found the Morso flu kit complete for £499 delivered, which isn't bad, and I found a 1200x1200 25mm board for £50, on top of that theres just bricks for hearth (height) tiles and cement. I'm just having a last look at the standard twin wall flu stuff (ie Shieldmaster) to see if I can make that work (for about half the cost of the Morso kit) but I'm unclear on the coupling to the stove and the roof plate thing, so the kit at least means it will all go together. Plus, I can get on and build the hearth while I wait for it to arrive as the Morso kit is adjustable, no need to worry about trying to calculate angled heights to the mm.

Crazy money, I built my flue from bits on eBay, think I'm around £200-£300 for the complete system including collar and chimney with cap...

[Johny London]

Hi Fuel,

 

I've decided to go that way - 25mm calcium silicate board and 10mm airgap. I've been going by the solifetec guide as well as Morso boat specific guide. I was a little unclear where Morso described the hearth itself - it seemed that any 12mm of non combustible material was all that was needed, presumably over the ply, but I have cut out the ply and am just building up from the base plate with brick and/or breeze block - whatever combination will give me a suitable height. I need to get higher than the ply by a good margin in order to allow for laminate floor to but against the hearth. There doesn't seem to be any regulation for hearth height over and above the floor and I don't want to create a trip hazzard, so I'll prolly go for 12mm to a couple of cm, whatever the bricks and blocks work out to.

A little more problematic getting sufficient hearth around the stove so I'll go with the raised edges which allow the distances to be reduced.

 

Dave, I wouldn't say its crazy money (£499) for the Morso flue kit - if you spent maybe £300 for bits off ebay. I priced up all the ebay stuff and for me it came to about £375 and I was still left wondering if I would have trouble with the roof join (console plate?) plus the 15degree bends would have been asthetically a little too much, Morso do 12 degrees which I guess it typical for boat sides? Also have I'd ended up with quite a collection of bits and more joins going the ebay rout. Don't get me wrong - if you can do it well with cheaper off the shelf parts I'm all ears, but I'm living aboard and it's freezing now so just want it sorted!

 

I got the stove off ebay so started well as far as not spending too much, but by the time its all done I'll be in at a grand

 

I'll let everyone know how the install goes - off to Wickes for slate tiles today!

[rjasmith]

I was a little unclear where Morso described the hearth itself - it seemed that any 12mm of non combustible material was all that was needed, presumably over the ply, but I have cut out the ply and am just building up from the base plate with brick and/or breeze block - whatever combination will give me a suitable height. I need to get higher than the ply by a good margin in order to allow for laminate floor to but against the hearth. There doesn't seem to be any regulation for hearth height over and above the floor and I don't want to create a trip hazzard, so I'll prolly go for 12mm to a couple of cm, whatever the bricks and blocks work out to.

 

 

(Snipped quite a lot of your post and highlighted a bit in red!)

 

You're using the Soliftec drawing as many do but don't forget that this drawing is a major abbreviation of the BS 8511 Code of Practice and of course does not show all the approved guidance (not regulation!) that is in the full document.

 

If you do want guidance about hearth size and shape (and all sorts of other things plus many more drawings) it's all in the full document if you want to read it. There is also an explanation about the 12mm thickness dimension.

 

The easiest way to do this is to use the free service provided by Manchester City Libraries website which gives access to any British Standard.

 

It isn't the most user friendly method of accessing them perhaps but it is at least free and I use it regularly. (You can always buy your own copy of BS 8511 for about £200!).

 

I've written instructions on here several times about how to access it and will provide a link for you if you need them (if you don't - I can avoid the time trying to find them again !)

 

Richard

[WotEver]

If you Google for "BS8511 PDF download" there is at least one site that has it available. I've not copied the link nor named any sites for obvious reasons.

 

Tony

Edited October 12, 2016 by WotEver

[Dave Payne]

Details on the hearth

 

 

The required hearth design and/or construction is dependent on the performance of the appliance to be installed as follows.

 

a) For appliances tested according to BS EN 13240 for roomheaters and BS EN 12815 for cookers, which have been shown to give maximum hearth temperatures on the exposed surface not exceeding 100 °C (and documented as such in the manufacturer’s instructions), the appliance should stand wholly above a hearth of non-combustible board/sheet material or tiles at least 12 mm thick.

 

For all other appliances, a non-combustible hearth should be provided, made of: solid material, e.g. concrete or masonry; or material of lightweight construction, but suitable for the weight of the appliance, e.g. vermiculite or calcium silicate boards suitably protected on their surface, if necessary, to maintain their integrity.

 

The hearth should be at least 125 mm thick, including the thickness of any non-combustible floor and/or decorative surface. It may be less than 125 mm if placed upon a non-combustible hull structure. (See Figure 1 and Figure 2.)

 

Combustible material should not be placed beneath hearths described in unless there is an air space of at least 50 mm between the underside of the hearth and the combustible material, or the combustible material is at least 250 mm below the top of the hearth as detailed in Figure 1.

[Johny London]

Thanks, I'm really at the limits of what is possible in the space, and have done everything the safest way I can - theres not much else I can do other than get a wider boat but I'll have a gander at the bs thing when I get a chance.

Morso does say the hearth wont get hotter than 100 degrees so the 12mm thing is fine but I didn't like the idea of having wood under that, hence I cut the floor out! Breeze blocks, bricks and concrete ready to go

[BargeeSpud]

Thanks, I'm really at the limits of what is possible in the space, and have done everything the safest way I can - theres not much else I can do other than get a wider boat but I'll have a gander at the bs thing when I get a chance.

Morso does say the hearth wont get hotter than 100 degrees so the 12mm thing is fine but I didn't like the idea of having wood under that, hence I cut the floor out! Breeze blocks, bricks and concrete ready to go

 

 

That's because, if its a Squirrel, the stove has a heat shield fitted to the bottom & to the back which are highly effective in reducing the radiant heat. On my previous boat which had a Squirrel with heat shields, I could touch the back of the stove heat shield & keep my hand there for quite some time (30 seconds or more) with no serious discomfort, whereas the areas without the heat shield were impossible to touch without sustaining a burn.

Edited October 14, 2016 by BargeeSpud

[Johny London]

I don't think mine has a heat shield behind it. But I did notice that there is a significant difference in specified combustible distances between the 1410, 1430 and 1440 stoves.

Morso say 600mm all round for the 1430 whereas the others have typically 200 or 300 specified (depending on flu type). I wondered what the difference between the stoves was - now I know.

 

My hearth is built - engineering bricks then breeze blocks then slate tiles Just the sides to do with the air gap, 25mm fire boards and slate tiles, then I can start to worry about the flu - proper Morso offset kit so should be easy,

[Johny London]

I'm now wondering whether to build the fireboard infront of the ply side of the boat or cut the ply out altogether and replace it with the fire board - there's a decent gap behind then spray foam which I'm assuming must at least be fire retardant these days? It would give me a bit more space on the hearth that way. Anyone done it like that?

[Dave Payne]

i thought the same, you would think it would be ok if the air gap is big enough?

[WotEver]

Maybe I'm misunderstanding but the purpose of the air gap is to ensure that any heat conducted through the fireboard isn't passed to the wood behind it. Surely, if you're completely replacing the wood with fireboard then you have nothing combustible to protect? Ergo you don't require any gap.

[Johny London]

Hi Dave, I'll check the air gap distance, but I'm sure it's a lot more than the 10mm required. It seems like a good idea to me but then, thought I might run it past you guys to see if I've completely overlooked something.#

 

WotEver - Yes the wood cladding of the side of the vessel would be replaced with wood, so behind that would be the gap that exists anyway between wood and insulating foam, then the hull of the boat. I think the gap will be more than 10mm as there is room for flush mounted mains sockets (though will investigate!) so I'm really just wondering if the foam will mind getting slightly (?) warm or if there would be a problem with warm air being in one part of the vessels lining, or something like that that I have not thought of. Otherwise I think I might do it, potentially safer and gives more hearth space

[BargeeSpud]

I don't think mine has a heat shield behind it. But I did notice that there is a significant difference in specified combustible distances between the 1410, 1430 and 1440 stoves.

Morso say 600mm all round for the 1430 whereas the others have typically 200 or 300 specified (depending on flu type). I wondered what the difference between the stoves was - now I know.

 

My hearth is built - engineering bricks then breeze blocks then slate tiles Just the sides to do with the air gap, 25mm fire boards and slate tiles, then I can start to worry about the flu - proper Morso offset kit so should be easy,

 

If its a 1410 & less than 3 years old, it will, definitely - unless it has a back boiler fitted. Other models may be different, I only know the 1410.

[Johny London]

Hi,

 

All done and working now! The stove is a 1430. So doesn't have the heat shields. My hearth is tile/breeze block/engineering bricks down to the base plate - glad I went to the trouble of doing it that way as that part most definitely can't catch fire now

I did cut out the ply paneling on the boats side, replaced with cal sil board 25mm - I set it vertically too, not at the angle the ply was at, so aesthetically I think it looks better and it was a little easier to tile. Behind that I had a nice big clearance to any spray foam and even a passing baton was more than 10mm away. I imagine this air gap will work extremely well as it is effectively free moving. I cut out the gunnel wood too and tiled there - didn't like the idea of a lot of hot air passing that sticking out wooden edge.

 

The proper Morso flue kit went in ok - jigsaw for the hole which was surprisingly easy to do, but I didn't think much of their collar arrangement - just a flat piece of steel that needed sealing around. Still it's done now and I'm warm. I wonder if I'll have issues with the stove being a 1430 when it comes to the bss next year but everything I've done is as safe as could be done, I believe! Even got good clearance around the top of the flue by cutting all the ply and foam away... still need to make an internal metal cover for that.

 

Stove works beautifully - the flu is 5" with the double skin being inside that so effectively only 4", but it draws ok and it's what Morso supply specifically for boats. It's a very smooth, controlled burn - doesn't get too whooshy if you open it up, but doesn't tend to go out either - nice

 

Too late, I found a MUCH cheaper supplier of the Morso kit here : http://www.bowlandstoves.co.uk/acatalog/Morso-Squirrel-Boat-Fixing-Kit-62908511.html#.WBCDxLXTXnNat that price it's worth having.

[ditchcrawler]

Hi,

 

All done and working now! The stove is a 1430. So doesn't have the heat shields. My hearth is tile/breeze block/engineering bricks down to the base plate - glad I went to the trouble of doing it that way as that part most definitely can't catch fire now

I did cut out the ply paneling on the boats side, replaced with cal sil board 25mm - I set it vertically too, not at the angle the ply was at, so aesthetically I think it looks better and it was a little easier to tile. Behind that I had a nice big clearance to any spray foam and even a passing baton was more than 10mm away. I imagine this air gap will work extremely well as it is effectively free moving. I cut out the gunnel wood too and tiled there - didn't like the idea of a lot of hot air passing that sticking out wooden edge.

 

The proper Morso flue kit went in ok - jigsaw for the hole which was surprisingly easy to do, but I didn't think much of their collar arrangement - just a flat piece of steel that needed sealing around. Still it's done now and I'm warm. I wonder if I'll have issues with the stove being a 1430 when it comes to the bss next year but everything I've done is as safe as could be done, I believe! Even got good clearance around the top of the flue by cutting all the ply and foam away... still need to make an internal metal cover for that.

 

Stove works beautifully - the flu is 5" with the double skin being inside that so effectively only 4", but it draws ok and it's what Morso supply specifically for boats. It's a very smooth, controlled burn - doesn't get too whooshy if you open it up, but doesn't tend to go out either - nice

 

Too late, I found a MUCH cheaper supplier of the Morso kit here : http://www.bowlandstoves.co.uk/acatalog/Morso-Squirrel-Boat-Fixing-Kit-62908511.html#.WBCDxLXTXnNat that price it's worth having.

I doubt the BSS will give a dam so long as the surround is not showing heat damage and the stove is in good condition

[BargeeSpud]

I doubt the BSS will give a dam so long as the surround is not showing heat damage and the stove is in good condition

 

That's part of the conundrum, do we only build to a standard that will satisfy a BSS surveyor, or do we do more to satisfy our own peace of mind? Whatever level of standard an individual decides to take his project to, we all know that the BSS/RCD is the minimum that has to be met & therefore anything done that exceeds the basic requirements simply has to be right. Simple. I think.

 

Its those sorts of decisions that make build discussions between us so fascinating, interesting & sometimes a little testy!

Edited October 27, 2016 by BargeeSpud

[Dave Payne]

Done a really stupid thing today, my stove is in, have sealed the collars and flue, just need to tile the fireboard now....

 

Stumbled across the report on the sad accident on nb lindy Lou, now I'm crapping it that I've missed something or not done something right.

 

The one thing I am not sure on is the hearth, I have some 4x2 timber which makes the Hearth base then 25mm silicate board on top, then a piece of slate on top, no air gap between the three, the wood is only a frame and has air space with vents to allow heat out, does this sound ok?

[Johny London]

ok, but not as good as having no wood underneath (in my unqualified opinion!). Is it just the edges of the cal sil board that have the 4x2 or is there much of it running right underneath the stove?

I imagine it wasn't so long ago people would have just plonked a stove down on tiles and hoped for the best so it's good that we can have these discussions and gather more knowledge.

[ditchcrawler]

Done a really stupid thing today, my stove is in, have sealed the collars and flue, just need to tile the fireboard now....

 

Stumbled across the report on the sad accident on nb lindy Lou, now I'm crapping it that I've missed something or not done something right.

 

The one thing I am not sure on is the hearth, I have some 4x2 timber which makes the Hearth base then 25mm silicate board on top, then a piece of slate on top, no air gap between the three, the wood is only a frame and has air space with vents to allow heat out, does this sound ok?

I would be happy but I am not qualified to advise you if its safe. My view would be will the Slate ever get hot enough for that head to pass through the silicate board down to the wood and ignite it. I have seen shoves with tile surrounds straight onto wood where the tiles get so hot that you cant touch them and the wood behind has been chard. Its a judgment you have to make, how hot does the bottom of the stove get?

[Dave Payne]

The silicon board only rests on the edge, so 2" round the front and sides, I have not finished tiling yet so I can see the wood stil, I think I might leave this with no tiles whilst in light the stove a couple of times to see if the heat goes through tile, silicon board and if so how hot the wood gets.

 

I imagine a lost of boats have this set up, the only other way is to replace wood with concrete, but then it means removing floor and sitting on the steel.

[Johny London]

It's good you can see the wood - why not leave it like that for quite a while until you are totally happy? You can touch the wood too and see if it gets warm or not. If it's any help, at the edge of my rear cal sil tiled board, where it protrudes forward a bit (because I fitted it vertically not sloped) I can feel that very little heat indeed passes into the cal sil itself. I guess that's its property, not to get hot hence not transfer heat. Obviously the air gap is good to have as well as a second line of defense, but if the board itself isn't getting hot you might be ok?

[Dave Payne]

Yeah sounds like a good idea, ill tile round the back and sides of the stove and leave the capping and around the hearth for a while till im happy.

 

Do need to pick up some smoke alarms though, already got carbon monoxide ones.

[Johny London]

Maybe you could incorporate a little ventilation for the air gap? I think someone on here did.

[Dave Payne]

the top of the fireboard and down the sides, after being tiled will be wood trim with holes drilled so the air can circulate, the wood under the hearth has a gap at the back, i might put a couple of holes in the front also to allow circulation there.