Alternative to fireboard

[jnrhacksaw]

I have a 100mm gap between my stove and a steel bulkhead.

 

Its recommended that there be a 45mm air gap then 25mm calcium silicate board with another air gap of 10mm.

 

However fireboard is expensive, over a £50 for a 1m square sheet. are there any other alternatives? at the moment the burner is surrounded with the steel of the hull and the bulkhead there's nothing flammable within 500mm

 

[W+T]

Not sure, but maybe a 50mm cavilty behind the tiles filled with vermiculite.

[blackrose]

B&Q have a fire resistant board for about 12 quid for a 2.4m x 1.2m sheet. I'm not certain it's suitable so perhaps someone else can advise?

 

http://www.diy.com/departments/gyproc-fireline-square-edge-plasterboard-l2400mm-w1200mm-t125mm/35764_BQ.prd

[wonderdust]

I have a 100mm gap between my stove and a steel bulkhead.

 

Its recommended that there be a 45mm air gap then 25mm calcium silicate board with another air gap of 10mm.

 

However fireboard is expensive, over a £50 for a 1m square sheet. are there any other alternatives? at the moment the burner is surrounded with the steel of the hull and the bulkhead there's nothing flammable within 500mm

 

Plasterboard

[ditchcrawler]

I have a 100mm gap between my stove and a steel bulkhead.

 

Its recommended that there be a 45mm air gap then 25mm calcium silicate board with another air gap of 10mm.

 

However fireboard is expensive, over a £50 for a 1m square sheet. are there any other alternatives? at the moment the burner is surrounded with the steel of the hull and the bulkhead there's nothing flammable within 500mm

 

No lining in that part of the hull?

[rupertbear]

I think that there is a lot of confusion about the various type of board. My understanding (will be happy to be corrected) is this:

 

The expensive type of board, known as Calcium Silicate board, is a very good insulator. If one side is heated, the other side does not get hot (simplification).

 

The cheaper 'fireboards' do not burn in the way that plywood would if heated. They are, though, poor insulators and will let the heat through.

[mrsmelly]

I have a 100mm gap between my stove and a steel bulkhead.

 

Its recommended that there be a 45mm air gap then 25mm calcium silicate board with another air gap of 10mm.

 

However fireboard is expensive, over a £50 for a 1m square sheet. are there any other alternatives? at the moment the burner is surrounded with the steel of the hull and the bulkhead there's nothing flammable within 500mm

 

 

Aquapanel.

 

Tim

[Sweeny Todd]

We used the B&Q board mentioned above on our last boat. Its been up 3 years without any issues. Nearest point to the fire is approx 3 inches. Using a similar board on the new boat which we got from Buildbase.

[ditchcrawler]

We used the B&Q board mentioned above on our last boat. Its been up 3 years without any issues. Nearest point to the fire is approx 3 inches. Using a similar board on the new boat which we got from Buildbase.

But have you looked behind it, Ceramic Tiles will look OK for years but when you take them off you may fined chared wood behind them. A friend of mine had a fire start behind the tiles.

[saltysplash]

Another vote for Aquapanel or Cement board. just done my surround with it, suitable for tiling and its non-combustable.

 

About £17 quid a panel in Wickes and they currently have a 3 for 2 offer.

[Neil Smith]

Aqua panel is not a fire board its a waterproof panel for shower cubicles instead of plasterboard on stud walls that you tile on. why cant you tile directly on the steel bulkhead.

 

Neil

[Murflynn]

Aqua panel is not a fire board its a waterproof panel for shower cubicles instead of plasterboard on stud walls that you tile on. why cant you tile directly on the steel bulkhead.

 

Neil

but it is non-combustible, structurally very strong and a relatively good insulator.

[canals are us?]

I used this recently. http://www.diy.com/departments/hardiebacker-12mm-cement-backerboard-for-tile-stone-l1200mm-w800mm-t12mm/136777_BQ.prd A fellow boaters stove was causing the wood to scorch so cut it all away, lined with fireboard from hearth and walls up to ceiling and retiled. Installed new glass and rope and repainted the stove.

The fire rated plasterboard isn't the right stuff as it's paper faced.

 

James

[John V]

I used hardibacker board, cement based and where it is close to very hot sections (ie round the flue) I put a second layer spaced on 10mm aluminium channel as a heat shield. The channel vertical so that there is a good airflow between the layers.

[smileypete]

Aqua panel is not a fire board its a waterproof panel for shower cubicles instead of plasterboard on stud walls that you tile on. why cant you tile directly on the steel bulkhead.

 

Neil

 

ISTR someone put an offcut IN their stove and it suffered very little harm. An easy test to repeat...

Edited February 6, 2016 by smileypete

[clbrof]

Aquapanel from Wickes is the best bet as long as you can securely fasten it, as it is quite heavy

[Richard T]

People are getting confused - a material can be inflammable but still a good conductor of heat for example steel! and ceramic tiles!

The recommendation is for a material that is inflammable and most importantly does not conduct heat through it (an insulator) e.g calcium silicate board. When we fitted our stove I spoke to the manufacturer of Hardibacker - it is only good for insulation up to 100deg C. This was fine for sitting the stove on as the manufacturers stated temp at 75mm from the bottom of the stove was only about 80deg C. However this figure rose considerably around the side of the stove so only calcium silcate with air gaps would do.

Calcium silicate is not cheap - I found the best price for a small quantity was Midland Chandlers but for a large amount Sheffield Insulations would probably be cheaper.

Do not skimp on this your life and that of others is at risk if you get it wrong!!

[bastion]

People are getting confused - a material can be inflammable but still a good conductor of heat for example steel! and ceramic tiles!

The recommendation is for a material that is inflammable and most importantly does not conduct heat through it (an insulator) e.g calcium silicate board. When we fitted our stove I spoke to the manufacturer of Hardibacker - it is only good for insulation up to 100deg C. This was fine for sitting the stove on as the manufacturers stated temp at 75mm from the bottom of the stove was only about 80deg C. However this figure rose considerably around the side of the stove so only calcium silcate with air gaps would do.

Calcium silicate is not cheap - I found the best price for a small quantity was Midland Chandlers but for a large amount Sheffield Insulations would probably be cheaper.

Do not skimp on this your life and that of others is at risk if you get it wrong!!

Well said. I have been trying to think of the right reply to this question and you have answered it perfectly. Do not cut corners by using aqua-panel!!!

[ditchcrawler]

People are getting confused - a material can be inflammable but still a good conductor of heat for example steel! and ceramic tiles!

The recommendation is for a material that is inflammable and most importantly does not conduct heat through it (an insulator) e.g calcium silicate board. When we fitted our stove I spoke to the manufacturer of Hardibacker - it is only good for insulation up to 100deg C. This was fine for sitting the stove on as the manufacturers stated temp at 75mm from the bottom of the stove was only about 80deg C. However this figure rose considerably around the side of the stove so only calcium silcate with air gaps would do.

Calcium silicate is not cheap - I found the best price for a small quantity was Midland Chandlers but for a large amount Sheffield Insulations would probably be cheaper.

Do not skimp on this your life and that of others is at risk if you get it wrong!!

I don't think anyone is listening

[John V]

People are getting confused - a material can be inflammable but still a good conductor of heat for example steel! and ceramic tiles!

The recommendation is for a material that is inflammable and most importantly does not conduct heat through it (an insulator) e.g calcium silicate board. When we fitted our stove I spoke to the manufacturer of Hardibacker - it is only good for insulation up to 100deg C. This was fine for sitting the stove on as the manufacturers stated temp at 75mm from the bottom of the stove was only about 80deg C. However this figure rose considerably around the side of the stove so only calcium silcate with air gaps would do.<snip

 

I suspect that Hardibacker may have been pessimistic in their figures. When I installed my stove and the Rayburn I used Hardibacker.

The board has been used instead of the ply lining rather than on top of it as is so often the case so all that is behind it is 2" of rockwool.

and as I said where there was high exposure to heat (behind the flue) I fitted the "heatshields" as mentioned. A few years ago I had a severe flue fire where the 6" single wall flue was glowing bright cherry red.....goodness knows what the temperature the heatshields were exposed to but it was a heck of a lot higher than 100 degrees. After this incident I examined the Hardibacker which had changed colour and become friable but was still intact and still acting as a heatshield for the board behind, which was still perfect.

I think possibly they were giving the temperature that the board degrades and loses strength and not when it would actually fail.

 

Not so much a recommendation to use Hardibacker against calcium silicate, more as reassurance for any one who has done so.

[Chalky]

Another vote for wickes aqua panel. I spent some time researching it and its a cement based board. I did find a manufacturers data sheet for it that specifies the thermal conductivity. From memory its conductivity was at the bottom end of the limit allowed by bs8511, but it is in the tables and a compliant design can be achieved.

Edited February 7, 2016 by Chalky

[Afloat]

......- a material can be inflammable but still a good conductor of heat for example steel! and ceramic tiles!.......

 

surely, incombustible!!

[WotEver]

 

surely, incombustible!!

Or non-flammable.

 

Inflammable and flammable are interchangeable.

[saltysplash]

Aqua panel is not a fire board its a waterproof panel for shower cubicles instead of plasterboard on stud walls that you tile on. why cant you tile directly on the steel bulkhead.

 

Neil

You can Tile directly on to Aquapanel

 

People are getting confused - a material can be inflammable but still a good conductor of heat for example steel! and ceramic tiles!

The recommendation is for a material that is inflammable and most importantly does not conduct heat through it (an insulator) e.g calcium silicate board. When we fitted our stove I spoke to the manufacturer of Hardibacker - it is only good for insulation up to 100deg C. This was fine for sitting the stove on as the manufacturers stated temp at 75mm from the bottom of the stove was only about 80deg C. However this figure rose considerably around the side of the stove so only calcium silcate with air gaps would do.

Calcium silicate is not cheap - I found the best price for a small quantity was Midland Chandlers but for a large amount Sheffield Insulations would probably be cheaper.

Do not skimp on this your life and that of others is at risk if you get it wrong!!

Aquapanel has a Thermal Conductivity W/mk of 0.35

My instalation has an almost 2" airgap between the panel and the bulkhead. The bulkhead is cool to the touch by placing the hand inside the airgap with the stove working.

This airgap also has an airflow gap at the bottom and the top to allow air to circulate behind the panel.

 

Well said. I have been trying to think of the right reply to this question and you have answered it perfectly. Do not cut corners by using aqua-panel!!!

 

Aquapanel is very safe when fitted following the guidelines in BS8511

[smileypete]

 

I suspect that Hardibacker may have been pessimistic in their figures. When I installed my stove and the Rayburn I used Hardibacker.

The board has been used instead of the ply lining rather than on top of it as is so often the case so all that is behind it is 2" of rockwool.

and as I said where there was high exposure to heat (behind the flue) I fitted the "heatshields" as mentioned. A few years ago I had a severe flue fire where the 6" single wall flue was glowing bright cherry red.....goodness knows what the temperature the heatshields were exposed to but it was a heck of a lot higher than 100 degrees. After this incident I examined the Hardibacker which had changed colour and become friable but was still intact and still acting as a heatshield for the board behind, which was still perfect.

I think possibly they were giving the temperature that the board degrades and loses strength and not when it would actually fail.

 

Not so much a recommendation to use Hardibacker against calcium silicate, more as reassurance for any one who has done so.

 

Good to hear it held up well enough, though Hardibacker is reinforced with cellulose which might explain why it became friable under extreme heat. Aquapanel is reinforced with glass fibre which should hold up to heat a bit better.

 

That said, Hardiebacker is commonly used for lining fireplaces behind stoves:

 

http://www.stovefittersmanual.co.uk/articles/lining-a-fireplace/

 

I dug up a paper last night that suggests ordinary cement starts to lose strength at 300C but it doesn't drop off catastrophically:

 

http://www.iiste.org/Journals/index.php/CER/article/download/3872/3931(468kB)

 

ETA There was a similar discussion here on these materials a few years ago:

 

http://www.canalworld.net/forums/index.php?showtopic=57087

 

cheers, Pete.

~smpt~

Edited February 7, 2016 by smileypete