Kilns are in effect large ovens, used for a variety of purposes from firing pottery, drying bricks to burning limestone.

A replica updraft kiln, built for Surrey Rural Industries Day at The Rural Life Centre, Tilford, June 2008
Image: Janet Nixon

Updraft kilns were permanent structures in which the air passes from the base of the kiln out through the top. Material to be fired is placed on a natural or raised floor so that heat and fumes from a fire built adjacent or below the material is drawn up through and around it before passing out through a vent in the roof or superstructure. Technically, updraft kilns were very inefficient and were later replaced by superior downdraft kilns.

Reconstruction of a 13th century tile kiln found in Borelli Yard, Farnham
Illustration: Nicholas Riall

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