Stove air gap

[SilverComet]

Another novice question...

When the boat was purchased she had a multi fuel stove already installed, the owner had put a fireboard behind tiles all around the sides.

It sits with a probably 2cm air gap though on a wooden harth which makes me want to check this is safe before I do anything with it - anyone had this issue? It seems weird to me after all that to put it on something made entirely of wood.

Edited September 22, 2017 by SilverComet
Spelling

[David Mack]

You are right to be concerned.

https://www.gov.uk/maib-reports/fire-on-narrow-boat-lindy-lou-at-lyme-view-marina-adlington-england-with-1-person-injured-and-loss-of-1-life

"At about 0245 on 20 January 2007, a fire broke out on board the narrowboat Lindy Lou which was moored at Lyme View Marina, Adlington. One person died as a result of the inferno, which quickly swept through the boat. The other occupant, the owner of the boat, suffered from serious burns and effects of smoke inhalation."

"The most likely cause of the fire was the solid fuel stove, which had not been installed in accordance with the stove manufacturer’s recommendations, as the hearth dimensions, and the air gaps around the stove were less than recommended."

 

[manxmike]

I have just had my fire, flue and chimney sorted by Garry Spruce, he told me that the minimum air gap is 10mm. In my case we discovered that the tiles behind the fire were actually mounted on plywood - well, it used to be plywood, when a tile fell off we found it was now charcoal!

I ripped out the plywood behind and beside the fire, removed the melted polystyrene and installed 6mm cement board (Hardie Backer) with a fairly generous air gap to the hull. I'm going to put new tiles on to replace the dreadful small square white tiles that were there.

I realised when I was stripping out the charcoal board that I have been incredibly lucky that the boat hadn't gone on fire. Since I plan my next boat to be a sailaway, fitted out by me, that's one problem I won't have to face - the fire will be backed by cement board and will be mounted on a fireproof base and installed by (hopefully) Garry!

[Bloomsberry]

Silver foil fixed to the sides of the hearth immediatly to the sides of the stove do a great job of reflecting the heat.

I tried it and couldn't believe how cold the tiles were behind it , it doesn't look too great but it works very well.

Could be a solution if you're concerned about the hearth of your own boat.

[Mohsen]

13 hours ago, manxmike said:

I have just had my fire, flue and chimney sorted by Garry Spruce, he told me that the minimum air gap is 10mm. In my case we discovered that the tiles behind the fire were actually mounted on plywood - well, it used to be plywood, when a tile fell off we found it was now charcoal!

I ripped out the plywood behind and beside the fire, removed the melted polystyrene and installed 6mm cement board (Hardie Backer) with a fairly generous air gap to the hull. I'm going to put new tiles on to replace the dreadful small square white tiles that were there.

I realised when I was stripping out the charcoal board that I have been incredibly lucky that the boat hadn't gone on fire. Since I plan my next boat to be a sailaway, fitted out by me, that's one problem I won't have to face - the fire will be backed by cement board and will be mounted on a fireproof base and installed by (hopefully) Garry!

I thought that cement board of this type wasn't ideal and instead calcium silicate board was preferable. Could be wrong though 

[Dave Payne]

1 hour ago, Mohsen said:

I thought that cement board of this type wasn't ideal and instead calcium silicate board was preferable. Could be wrong though 

I think you are correct, cement board is really for wet rooms and the like to tile over.

Calcium silicate board has a higher density to minimize heat passing through?

 

I have a 10mm gap behind my calcium board, i dropped a thermometer down there when the fire was raging and i recall it barely went over 70c.

 

[WotEver]

Otherwise known as Vermiculite board I believe. 

[cuthound]

1 hour ago, WotEver said:

Otherwise known as Vermiculite board I believe. 

Indeed, used a fire stopping between floors in cable risers within tall buildings.

Edited September 27, 2017 by cuthound
Missing letter

[manxmike]

You're probably right about the calcium silicate board, but I have been assured that the Hardie Backer 6mm is more than adequate for the purpose - and it was easy to get hold of!

[Rob@BSSOffice]

Cement board is fire proof and won't combust - true - but it doesn't stop much heat radiating through. So the problem of the pyrolis will continue. You need 25mm calcium silicate board to be effective. Follow this advice to help keep safe from fire and carbon monoxide risks http://www.soliftec.com/Boat Stoves 1-page.pdf

[manxmike]

Rob - many thanks for the clarification. At least I have left a decent air-gap behind the cement board. Another piece of excellent info for the new build!

[SilverComet]

Thanks all. Think I'll get someone to do it, I'm not incapable at DIY but I also don't want to risk it, it doesn't make sense.

Does anyone have any suggestions for a good company/person in the Leicester area?