Before the brands, the materials
What is a masonry heater made of?
You do not choose a brand: you choose a material, a thermal behaviour and a look. The manufacturers come afterwards, and that is the order in which we present them.
Grog
Grog is clay fired at very high temperature then crushed, reused as a refractory raw material. It is the material of the heater core: the part that takes the flame directly and must withstand sudden temperature rises, twice a day, for decades.
- What it brings
- A resistance to thermal shock that no ordinary building brick can match, and high thermal inertia: this is what holds the heat.
- What it costs
- The material is heavy, expensive per kilo, and is laid with refractory mortar — not cement. A repair means opening up the structure.
- Where we buy it
- From our firebox and refractory material suppliers, including Skamol and the certified manufacturers we work with.
Stove tiles
A stove tile is a glazed terracotta tile, moulded and fired specifically to clad a heating appliance. It is nothing like wall or floor tiling: its thickness, its expansion and the way it is fitted are designed for a substrate that moves and heats up.
- What it brings
- A surface soft to the touch even when hot, a deep colour that does not fade, and a lifespan counted in generations.
- What it costs
- It is the most expensive item in the cladding, and the lead time for a custom glaze is counted in weeks. A broken tile can be replaced, but you have to have planned for it.
- Where we buy it
- From the Austrian manufactories of the trade, which have been producing stove tiles for several centuries.
Raw earth and renders
Raw earth is a finishing render made of clay, sand and fibres, applied without firing. It covers the mass and lets it breathe, with a matt finish and a shade that comes from the soil it was dug from.
- What it brings
- A wall that regulates the room’s humidity, a texture that absorbs light, and a repair possible with a little water — something no cement render allows.
- What it costs
- It marks more easily than stove tiles and likes neither rubbing nor splashes of water. It needs the surface redoing after a few years in a busy spot.
- Where we buy it
- From eco-building suppliers, and sometimes straight from the ground on site when the earth is suitable.
A note of honesty: Tiileri, listed further down among the suppliers, is also a distribution activity of the group. We would rather write it than let you find out.
A masonry heater is worth what its components are worth. Here are the brands we choose, project after project — and which we also sell retail, kits, fireboxes, doors and refractory materials included, in our Cœur de Foyer shop.
Fireboxes and heater cores
Brunner — German glazed fireboxes of the very highest quality, which we build into our made-to-measure heaters; it is a Brunner firebox, for example, that equips the nursery school of the Mermoz school complex. Ortner — Austrian heat-storage systems and refractory castables, the benchmark for the modular heater core; the company, founded in 1983 in Loosdorf by master stove builder Josef Ortner, designed the KMS ceramic storage modules found on several of our projects. Biofire and Ecostove complete the range depending on the project. Thermasse is certified by these four manufacturers.
Finnish kits
Tiileri — Finnish masonry heaters in kit form, tiled and brick, which we supply for supported self-build or install ourselves. Models, colours and AirBox available through Cœur de Foyer.
Doors, hardware and materials
Pisla — Finnish firebox doors, cleaning doors and hardware fitted to our heaters. And every consumable the stove builder needs: firebricks and refractory slabs, grog, mortars, blankets and calcium silicate — sold retail in the shop, to professionals and private customers alike.
Two houses, one trade — Thermasse designs, calculates and builds; Cœur de Foyer supplies kits, fireboxes and materials to everyone. The same components as on our projects, with no trade minimum.