Insulating wall behind wood burner

[reb78]

As above. I am going to put a metal plate behind this woodburner. The plasterboard all around it is fire retardant

What's a suitable insulation to go behind the metal sheet I am going to put behind the burner to fill the cavity against the blocks?

 

[Arc Tourist]

Kind of hard to see in my old photo, but I built a layer of bricks up against a 3/8" plywood board and then removed the board leaving an air gap behind.
.

 

[Islander71]

You could use old pottery kiln bricks or maybe old storage heater bricks.

 

[reb78]

Isn't there a rock wool type product that's suitable? They fill the middle of twin flue pipes with something? I was thinking of a few sheets of that ideally but wasn't sure what, exactly, it was.

 

[wyn]

You could maybe use refractory board.

 

[Ian X]

Rockwool takes some beating. I incinerated a large amount of young weed plants for a friend in a spot of bother, they sat in Rockwool cubes and I folded the lot up and put it all into a well established blaze in an 11kW stove. In the morning the Rockwool cubes were perfectly intact and did not crumble or degrade when rived about.
If I understand correctly the binder used in manufacturing fails at 250c but the structure remains undisturbed.

 

[Shedendman]

Ceramic Fibre Blanket 1260°C -per Metre

VITCAS Ceramic Fibre Insulation Blanket offers low thermal conductivity and high tensile strength, withstanding temperatures up to 1260ºC (2300ºF). Available by the metre, it comes in 13mm and 25mm thicknesses, 610mm wide, with a density of 128kg/m³, ideal for high-temperature insulation.

shop.vitcas.com

Just stick this to the wall first to keep in place then screw the metal plate over it into the wall each corner and one in the middle if you want

 

[Agrismith]

Vermiculite board is designed for this I believe. Or at least often sold by stove companies for this purpose

 

[jenki]

Rockwool gets my vote

 

[julianthegypsy]

I've used Glassroc or Master board many times. Glass fibre compressed with cement. Only 6mm thick, slightly flexible and easy to score and snap. That provides a barrier and the steel in front acts as a heat diffuser preventing super hot spots.