I have not used vermiculite board but it is only good for 780 C or 1400 F. Batch stoves run much hotter than that.
I had 1750 F insulated fire brick fail after five days as the temps in the box were exceeding that.
So my guess is your boards were going to crack soon even if you didn't move your stove.
Most ceramic fiber board is good for 2300 F 1260 C. Some is rated higher.
It is also subject to damage by abrasion as well as (sorry) movement.
If moving your stove is something you plan on doing. Then Firebricks are the most durable.
Fraser, I know of one online shop in the Netherlands which sells the ceramic fibre board. https://kachelmaterialenshop.nl/53-keramisch-board- Before you order online, phone them up and ask if the material you want to buy is available. I'd suggest you line the firebox with firebrick splits, it is too easy to damage the walls just by shoving fuel in. The riser doesn't need to be protected. Over time, the riser's walls are starting to sinter and a rigid layer is formed.
More than one of my experiments were built out of 50 mm (2") material and were just screwed together. Use long stainless steel screws and caulk the seams.
Luke Perkins wrote:What is your experience using fire brick splits in a batch box lined with fiber board? Do the bricks tend to last for a long time or do they break and need to be replaced within a year or two?
I did only one experiment using split fire bricks inside a CFB box, pushed to its very limits as usual. The bricks seemed to hold well, don't forget those are able to get red hot again and again without any visable damage. My concern would be about the CFB.
Do I expect the splits need to be replaced within a year or two because of heat damage? The answer will be a firm no, not likely, think of counting in ten or more years.
fraser stewart wrote:"caulk the seams" is that with heat proof stove silicone kit. The black stuff?
The heat proof silicone kit is not up to the job in my opinion. What you need is the black stuff, I have good experience with that. The best out of three was the one from Bison saying "Openhaarden Kit" and "Mastic Refractaire" on the tube. Resistent up to 1250 ºC, 530 grams in a tube.
posted 1 week ago
Thanks for all the help guys. Especially peter for the local knowledge. What a great community