A Finnish masonry heater kit assembled in the Pays d’Auge, at Saint-Hymer, in spring 2018.
The house is new, timber-framed: wood-fibre boards still exposed, OSB ceiling, large glazed opening onto the garden. As always in this case, the heater was planned with the building rather than added afterwards — the floor is reinforced beneath it and the flue route allowed for at the design stage.
The heater is built in light-coloured refractory blocks, laid with fine joints. It stacks a glazed firebox at the bottom and a cooking chamber closed by an arched door above, within the single volume of a rectangular mass.
The principle of the kit is to deliver the heater’s parts preformed in the factory. The storage elements arrive moulded, with internal partitions: the flue gases flow through compartments designed in advance, which guarantees the flow cross-section without having to cut a single brick. The builder assembles and shims; they do not calculate the path.
It is the route that makes a masonry heater achievable without weeks of masonry — and the one often chosen for supported self-build.
