Operations in Auvergne 2003

The following account is of two projects undertaken by Pyromasse In Auvergne during the summer of 2003. Both contracts came from the pyromasse web site, one being in La Creuse the other in the neighbouring department of Puy de Dôme.

Creuse. The location of the project was a small hamlet in the extreme south east of the department. There are 7 dwellings in the hamlet, the heater being built in the house of its former wealthiest resident, Msr Parrie. The granite residence that dates from the 1840's, had stood derelict for the last 25 years, and was now undergoing complete renovation.

See also: Technical Documents PDF Index

The house at left with adjoining barn. The chimney is the one used by the heater.

The house well in a corner of the basement.

The barns gable with cross made from wine bottles, a Creuse tradition.

Decorative Stencil

Plans of a house

Traditional ovens

Old Masonry Tools

The object of the project was to build a Finnish style contra-flow heater into the large recess of the original "Walk in " granite fireplace, avoiding the heaters protrusion in to the main living area as much as possible. Consequently the heater was placed in the centre of the existing fireplace 2 inches from its rear wall, directly beneath the chimney.(The 2 inch space allows thermo-siphoning of heat of the rear face of the heater.)


The original granite fire place with its oak mantle and rifle racks. The cast iron plate at the back of the hearth radiated into the room behind, in which there was a false fireplace surround with the cast iron plate, and its high relief crest, as its centrepiece.

Detailed image of plaque

The buildings basement was of vaulted stone and could evidently withstand the weight of a masonry heater.The heater rests directly upon the shoulder of the vault above right.

Large portions of the original chimney breast had to be broken away to accommodate the height of the heater.

Drawings of the original fireplace.

Side Elevation
Front Elevation
a) living room
b) Small room behind living room.
c) Smoke hood and flue of walk in fire place
d) false fire place surround in the small room.
e) Cast iron plaque in rear wall of fire place.
f) Oak mantle.
g) Granite columns and arms supporting the upper structure.
h) A hole through the wall once allowed a wood stove located in the rear room, to vent into the flue of the walk-in fire place.

Designe J-M

View of the former location of the false fire place in the rear room. Note the 200mm round refractory flue tile which would be used to reach and connect to the steel flue pipe. a section of brick chimney was laid up to the top of the stainless steel flue pipe, which traverses the wall and runs to the top of the chimney on the roof. A shut off damper was placed in this new brick section of chimney at about 4 feet, between two of the refractory flue tiles used to connect the heater to the steel flue pipe. It was necessary to build this short section of chimney, to heat the rear room, and to help keep the heater back against the rear wall of the main fireplace. A chimney flue running up the side of the heater, in the main room, would have destroyed all symmetry.

The original chimney flue as it rises through the attic. In respect of code a stainless steel liner was installed throughout the flue's lift.


The refractory materials were shipped from Fayol SA. in Tain l'Hermitage. The castings from Upo in Finland. As a facing brick there was almost no choice. The bricks used are sold as a semi -refractory brick. Dense, solid and of modular format, they were ideal for facing a masonry heater. All other materials were acquired locally, the shut off damper being custom made in the next village.

The almost completed refractory core. Note the stainless steel flue pipe above the core entering the chimney from the room at rear.

View into the upper chamber of the finished refractory core.

The core with the first twelve rows of facing brick.


Though the house was built in the nineteenth century the brick façade of the heater would follow art deco lines. Local granite was used to make the vousars of the jack arc opening, to integrate the new brick heater with the old granite fireplace. The whole department is granite and so it was appropriate to use it as much as possible in the design of the façade.

The arches vousars were cut from pieces of granite found in the field and then boucharded.
This textured and flattened the surface of the weathered stones. Note the cardboard template for one of the vousars, on the ground at left.

The completed granite jack arch, just before jointing.

Granite squares were cut and laid in to the side and face of the heater. This enhanced the effect of the granite in the arch. Note the signature PM03 CREUSE to distinguish the heater from the only other heaters available in that area of France, which are pre-fabricated kits.

The finished heater.

View completed project

Puy de Dôme

The second project was in an even smaller hamlet ( having only three houses ) 1000 m above sea level in the vicinity of Besse, Puey de Dome.
The clients were living in a pre-revolution farm house and were in the process of restoring the adjoined barn. It was in the barn that a Finnish style heater was built.

The farm house seen from the rear. Originally the house had an oven built into one of its outside walls. The long collapsed oven and protective housing were outside the house, the loading opening and avaloir ( still intact ) opened into the kitchen through the exterior wall. The residence is dated 1765 on the door lintel.

Architectural detail

The materials were of identical quality and origin to those used in Creuse. Local refractory products were available, though I chose to use materials I knew from Fayol sa in Tain L'hermitage and Upo of lappi. The Co-ordination and back up for the upo castings was by Maine Wood Heat Co.
Due to a lack of choice the same facing brick used on the Creuse Project, was employed here.

Due to the abundance of stone in the Central Macife there was no problem to find specialised cutting equipment.

Heater with half of the facing laid up. Note the original stone barn walls, not the ideal interior surface for a house heated by radiant heat.

Custom made shut off damper seated in a double skinned burnt clay flue tile with 200 mm. interior diameter.

The refractory core was built on an elevated concrete block foundation. The chimney being located on the right hand side of the heater.
The object of the project was to build and face the core along with 9 feet of chimney, in two weeks. To break up the stark contrast of the bricks them selves the jack arch over the fire box door was made from Volvic, a local, soft volcanic rock.

The vousoirs and key of the arch were cut from an old animal drinking trough that had been left full of water during winter and broken on freezing. Rather than boucharding the surface the original surface was kept as testament to the mason who worked it 100 years or more ago. Moss and spray paint were removed with bleach and a wire brush. The rock is said to have originally come from the quarry at Besse. The stone elements of the arch consist of a key and two vousoir. Each vousoir has two false joints cut in to it to give the impression that there are three separate vousoir each side of the key.

The 13th day.

View completed project

Marcus Flynn

Montreal QC.

Articles by Marcus Flynn

Contact Pyromasse