The knotted ( or "nocciolato") mixture is the typical cotto of the Po valley. The lumps or color spots which are on the surface of the tiles are due to the clays of different natures. When rivers were without banks, the floods brought also clays from different places ( the Apennines, the Alpes..)and of different colors and composition.
These clays, sedimenting and overlapping in layers, have formed the current alluvional soils.
For centuries the extraction of clays by small furnaces around the area was made manually. The further operation was wetting the clay mixture with hoes, trying to uniform the mixture which normally was rather rough.
During cooking, clays of different nature showed with knots of different color and intensity.
Since the mixture was produced with rudimentary methods (hoes and shovels), at the time of shaping the clay into wooden molds only with manual pressure, it is obvious that blowholes remained trapped in the mixture. They were highlighted by larger or smaller holes on the surfaces of the tiles once they were smoothed manually ("orsatura")or worn by footsteps. Some blowholes which are a few millimeters down the surface, may appear even after laying.
The above can be regularly found in the old floors produced by hand in the past centuries. Fornace Polirone proposes, with their own methods of processing, this type of traditional floor.
On sample or drawing of the customer, we can realize any format, tone and pattern.
The knotted handmade terracotta floor of the Po valley has very marked differences in colours and sizes depending on the area.
The areas of Milan, Pavia, Brianza and Ticino were characterized by rectangular tles "medoni" with dimensions from 36x18 cm to 44x22 cm approximately. In representative romms the tiles of this size were laid side by side, almost no spacing; in the service rooms the dimensions were reduced: 29x14,5 cm, 28 x 13,5 cm etc..
In Emilia and lower Lombardy, the rectangular size 25x12 cm and 28,5x13,7 was very widespread.
The square 22x22, 25x25 and 28x28 cm was for the rooms of the most important buildings.
The squares with more than 30-35 cm side were very rare and made only for churches and prestigious buildings with very large rooms. These tiles were adjusted in order to obtain a perfect side by side and jointless laying.
In Veneto ( in the area of Venetian villas), it was common to find square tiles with sides from 24 to 30 cm, laid as checkers with the contrasting colors of straw yellow and red. The red tiles included yellow veinings as well as the yellow tiles included lumps in the red spots.
Watch the historic film about production of cotto tiles and bricks.

Examples about tiles of old floors

  1. Medone Lombardo
  2. Quadro rosato lombardo
  03. Quadro rosso cremonese
  04. Nocciolato veneto bicolore
  Pavimento sacrestia "Certosa di Pavia"
  Particolare pavimento sacrestia "Certosa di Pavia"