Guédelon chantier médiéval

The construction > The materials

The materials

The architectural and historical context

Guédelon's building plans

The methodology

The materials

1997 - 2010: Building timetable

Diaporamas

A site of strategic importance

Guédelon DR

Guédelon DR

A site of strategic importance

 

The siting of a castle was never left to chance. Whether built at a tactical location controlling lines of communication, or to dominate a region as a display of power and authority, the building of a future castle was always the fruit of a strategic approach; Guédelon is no exception to this rule. The site was chosen principally because of its close proximity to suitable construction materials. Transport was extremely costly in the Middle Ages: numerous taxes and tolls could double the value of the supplies.

On top of this, transporting goods - whether by road or by waterway - could considerably lengthen the construction time.

© Guédelon (DR F. Folcher)

© Guédelon (DR F. Folcher)

It was therefore necessary to find a site where the workforce would have access to the necessary raw materials.  At Guédelon we found an oak forest, an abandoned stone quarry, clay, sand and water - we couldn't have asked for more.

 

Another unexpected stroke of fortune gave the project an auspicious start: the geographic name of the surrounding lands.  Forêt et Etang de Guédelon: the evocative names seemed predestined for this medieval venture.

Stone: ferruginous sandstone

© Guédelon

© Guédelon

Stone: ferruginous sandstone

 

This stone is found in the construction of various local buildings, from the great and prestigious edifice of Ratilly castle to the more modest poyaudines houses.

This stone contains 30-40% iron oxide; this can make it extremely hard to extract and dress.  Depending on its level of iron oxide or ochre pigments, its colour varies between honey shades - low-quality friable stones - and charcoal-black - very hard stones.

It is extracted directly from the quarry situated at the foot of the castle's walls.

© Guédelon

© Guédelon

Quarrying techniques

 

Having studied the block in order to determine and anticipate the natural fault lines of the stone, the quarrymen first carve a series of rectilinear holes into the block.  Iron wedges are then hammered into this line of holes. The shockwaves produced by the quarrymen's sledgehammers cause the stone to split along a straight line. The highest quality blocks are dressed to produce lintels, voussoirs, corbels, ashlars etc.

The medium quality blocks are roughly shaped by the stonecutters and used on the uncoursed curtain walls, and as facing stones on the castle's inner walls.

© Guédelon

© Guédelon

Finally, a severely restricted budget, as valid in the Middle Ages as on the Guédelon building site, means that materials cannot be wasted.  For this reason, the poor quality, friable stone and waste from the quarry are bound with mortar to form the walls' rubble cores (the average width of Guédelon's walls being 3.5m). 

Depending on their future location in the castle, the blocks are then transported by horse-drawn cart to the stonecutters' lodges or hoisted on to the curtain walls using the "squirrel cages" - the treadmill cranes.

For certain more intricate features (crossed-ribbed vaults, two-light windows etc.) limestone from a nearby quarry is used.

Wood: oak

© Guédelon

© Guédelon

Wood: oak

 

A supply of wood was of vital importance in medieval construction: galleries above the wall-walks, hourds at the towers' summits, walkways, bridges etc.  However, the fact that wood rots means that very often there is little or no trace of its exterior uses; only a small number of roof timbers have survived.

Oak is the predominate wood found in Guédelon forest.  The woodcutters plan each felling according to the precise needs of the construction: a certain tree, of a certain section, of a certain height will be selected to make a fireplace's lintel or a purlin for the north range. 

Ochre and clay

© Guédelon

© Guédelon

Ochre and clay

 

Guédelon is situated in an area called Puisaye, renowned for the quality of its ochre and clay, the presence of which has given rise to a long-standing tradition of ceramic-making. 

On the site, clay is used in two different ways: clay soil, which is used in making the mortar and the wattle and daub walls; and fired clay which is used to make the roof tiles and decorative floor tiles.

Mortar

© Guédelon

© Guédelon

Mortar

 

The mortar is the "glue" used to bind the castle's stones.  It is made up of precise doses of lime, sand and water.  It is very important to respect the dosage of the different components; a mortar which is too "lean" - lacking in lime - would be too friable and would not act as an effective binder.

  

For safety reasons, lime cannot be burnt on site; it is delivered to the site in the form of slaked lime.  The slaked lime is then stocked in water-covered pits.  The workers responsible for mixing the mortar are called les gâcheurs

Daub - Roof and floor tiles

© Guédelon

© Guédelon

Daub

Clay is also used as "daub": a sticky building material usually made of some combination of soil, clay, sand, straw and water.  This mixture is then daubed onto a woven lattice of wooden strips called wattle.  It is used to make the walls of various different workshops.

 

Roof and floor tiles

There are water-filled clay pits in the forest.  Clay is taken from these pits, cleaned and pugged.  It is then shaped in wooden moulds to form roof and floor tiles.  After the tiles have been left to air-dry, they are fired in a wood-fired kiln for about 12 hours, at roughly 1000°c.

 

 

book
la boutique en ligne
Newsletter

Teachers

Journalists

Newsletter A castle in the making

Participate in the building of Guédelon castle

Downloads

Contacts

Recherche

guédelon updates


Warning: mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource in /home/guedelon/pro/web/include/offres.php on line 6

Chantier Médiéval
de Guédelon

D955 89520 TREIGNY
tél. 03 86 45 66 66

Infos légales Plan du site