C
Colour Republic
I think he may be refering to when it is slightly raised on a plinth
that’s right, the hearth is normally raised above the carpet or the surrounding floor carpet - in fact it’s a legal requirement of building regs (the dimensions are defined) and you'll find it also under HEATAS guidance. Trav is too soft to form a hearth base, as CR indicates, the edges will last 5 minutes!
Even good trav is about 5~10% resin – I personally wouldn’t go near it for a hearth ref metal tongues and cinder damage – as you say you can have custom cut two pieces of granite that will butt up to form an invisible joint (one for under the appliance and the other cut to legal dims at the front of the appliance to dims to the side to combustible materials and to front forward of the fire door). The front you can have bullnosed and it will still look perfect 10 years after your trav is trashed.