The PRAC kit is a masonry heater delivered as pre-cut refractory elements, to be assembled from a bonding plan. It makes accessible a build that, in small bricks, would take weeks of cutting — without giving up the principle: a firebox, then a long flue path through the mass.
This picture explains the heated bench better than any diagram. It shows that the seat is not just decorative masonry placed beside the heater: it is an extension of the flue path. The gases leaving the firebox travel several metres horizontally through it, give up their heat to the walls, and that is what keeps the seat warm for hours after the fire has gone out.
The first fire was lit on 4 June 2022, with the unit still bare. It is as much a technical moment as a symbolic one: we check the draught, the tightness of the joints and the behaviour of the glass, and begin the gradual drying of the mass, which still holds the water from construction.
A masonry heater is not run like a conventional stove: you make a brisk, complete burn, once or twice a day, air controls open, rather than keeping a smouldering fire going all the time. The heat is not in the flame, it is in the mass — and a brisk burn is the one that fouls least and emits least.
