QWhat adhesive should I use to stick ceramic tiles to super-Isol calcium silicate board for a fire surround and plinth for a multi-fuel stove, and what should I grout the joints with?
AFor the surround: If it will not flex or vibrate, I would use a bathroom/kitchen tile adhesive. Otherwise some swear by cork tile adhesive, but I would use a polyurethane sealer adhesive using the five-blob method or something like Marineflex/ Sikaflex. I would use a waterproof, flexible grout but you still might need to rake out and replace every few years if it falls out with vibration.
For the plinth: it depends on what standard the stove has been tested to. You might need concrete slabs or concrete cast into a mould built up from the baseplate to give a thickness of 225mm. See BS 8511. It all depends upon how much heat can radiate from the bottom of the stove.