A freestanding panel with two figures and the words 'Technical School'.
The terracotta frieze panel from the demolished Rochdale Technical School © Historic England Archive
The terracotta frieze panel from the demolished Rochdale Technical School © Historic England Archive

Understanding and Conserving Terracotta and Faience

Terracotta and faience are strong and durable building materials, yet they can degrade through lack of maintenance or damage. They may also suffer from manufacturing and/or construction defects.

The key to their conservation is an understanding of the processes involved in their design, manufacture and use in construction, as well as their mechanisms of deterioration.

The relationship between terracotta units, how they are fixed to the underlying structure, and the nature and condition of that substrate, are all crucial parts of understanding and conserving a terracotta facade or structure.

Further sources of information

TACS also provides a further reading list, and lists of conservators, restorers, manufacturers and suppliers.

Our Practical Building Conservation book ‘Earth, Brick & Terracotta’ (2015) covers:

  • History of architectural terracotta in England
  • Symptoms diagnosis of causes of deterioration including:
    • Manufacture defects: contaminants, inadequate firing, shrinkage, warping and cracking, glaze defects
    • Construction defects: block infill, bedding mortar and pointing, corrosion of embedded metalwork
    • Environmental damage: moisture and frost, temperature, pollution, deterioration caused by plants and animals
  • Condition surveys and diagnostic investigations
  • Treatment, repair, replacement and cleaning including:
    • Structural repairs
    • Temporary stabilisation
    • Repairing cracks or fractures
    • Glaze repairs

Image gallery

Please click on the gallery images to enlarge.