New masonry chimneys should be constructed with flue liners and components suitable for the application.
You can use pumice, clay, or concrete liners.
Manufacturers guidelines must be followed and the space between the liners and surrounding masonry filled with a weak insulating concrete backfill - ie leca, vermiculite, or perlite (unless manufacturers guidelines say otherwise). We recommend using leca as vermiculite can compress if it gets damp or wet, leaving the top of your chimney uninsulated.
The joints should be kept to a minimum and manufacturers offset components used if there needs to be an offset in the system.
Our advice: for a stove we would only recommend using pumice liners. We consider that clay or concrete liners are only really suitable for an open fire, but even for this application pumice would be better because pumice is a warmer material and therefore much less likely to lead to condensation in the chimney and will also promote good chimney performance.