Page 31 - Curriculum Visions Dynamic Book

(Above) Terracotta pots, a cheap, robust, and decorative material, especially when set against a contrasting colour, such as with the flowerpots in this scene in Mexico.
(Left and below) Terra cotta
is a bright red form of pottery that began in the Mediterranean region of Europe.
(Right) Terracotta wall light used for its decorative effect. Like all ceramics, it resists cracking when it is subjected to the heat of the light bulb.
structure makes the brick able to take much larger loads than other common types of ceramic.
Other building ceramics
Besides wall bricks there are
several other important categories of
building ceramic. terra cotta (a word
of Italian origin meaning “baked earth”)
is a strong, red-brown, porous fired clay. It
was the common building material of the ancient Mediterranean world and is now found all over Greece and Rome. It is used to make statues and vases as well as bricks and tiles. Terra cotta has even been used for the decorative shapes (architectural relief) on buildings.
Wall and floor tiles are made of fired clay that has been glazed. They are different from “quarry” tiles, which have been pressed so that the clay is dense and
able to withstand wear much better.
Special refractory bricks are used to line
chimneys, furnaces, and boilers (see page 32). Most tiles are glazed. High-fired glazes
are produced during the tunnel kiln process. The glaze (crushed glass in a liquid) is sprayed onto the bricks and tiles before they go into the kiln.
Low-fired glazes are used to obtain colours that cannot be produced at high temperatures. In this case there is a two-stage process: The tiles are first fired in the usual way, then the glaze is applied and the tiles refired at a lower temperature.
Glazes are not widely used on bricks because they make the brick impervious and do not allow the surface to breathe. That could leave damp inside a house.
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