Fi Jordan, Senior Ceramics and Glass Conservator, Sculpture, Metals, Ceramics & Glass Conservation Section at the Victoria and Albert Museum looks at the issues surrounding the conservation of ceramic tiles.

The conservation of tiles for museum display

Ceramic tiles have been used to decorate buildings and embellish architectural features since ancient times.  They have been incorporated in the design of floors, walls, ceilings and roofs as a non-structural surface finish for functional or decorative purposes.  The Victoria and Albert Museum (V&A), London, has examples of many diverse tile forms from throughout history.  Ceramic tiles on display in a museum will have been removed from their original settings for a variety of reasons, such as the destruction or change in use of a building, or an interest in the tile as a decorative art object.  It is important that there is an understanding of their original function and setting so that their re-display conveys their aesthetic and utilitarian appeal alongside the conservation requirements.

Although relocated tiles are not subjected to the same number of conservation issues as those remaining in situ, they will often retain problems acquired from their former environment.  For example, as a surface layer on a building structure, it is likely they will have been in contact with water, often from penetrating or rising damp, which can introduce water-soluble salts in low-fired earthenware tiles.  In some cases, this can result in the complete breakdown of the ceramic body and in the glaze flaking away from the surface.  Figure 1 (see left) shows cracking and glaze loss caused by salts crystallizing at the surface after fluctuations in environmental conditions.  Identifying the presence of water-soluble salts may influence the subsequent approach to display; for instance, if a decision is made not to remove them, then preventive control measures may be put in place.

All ceramics are highly susceptible to mechanical damage.  Tiles are likely to have suffered from wear and tear in situ and further structural damage during removal from their original substrate.  This can range from minor chips and cracks to multiple breaks and losses.  Even dirt can be detrimental; heavy soiling can permeate the body through cracks in the glaze, causing stains; encrustations can damage and obscure the surface decoration.

The decision to include a large number of tiles in recent gallery projects at the V&A has demanded a systematic approach.  Initially, a thorough assessment of their condition is undertaken so that the level of interventive treatment, to ensure stability and improve their appearance, can be agreed.  Often treatment involves dismantling old deteriorated restorations that are either putting the object at risk of further damage or are disfiguring.  In such cases, the dismantled fragments are cleaned and friable areas consolidated prior to re-bonding with an appropriate adhesive.  Options for the reconstruction of missing areas of the tile may be subject to discussion between curators and conservators.  Some chips may require filling on the grounds of stability, other areas may be partially or wholly reconstructed to make the losses less obtrusive (Figure 2 - see right).  Retouching is confined to the filled areas, either painted in a background colour or, if there is evidence, the decoration may be imitated.  As a tile is often displayed as part of a group, it is important to consider the appearance of each in relation to one another so that a consistent level of restoration is achieved.
 
Often the individual tiles making up a panel are in relatively good condition but the method or materials used to back them in the past may compromise their stability.  For example, the old traditional method of mounting tiles between a wood backboard and frame with no other means of restraint may have resulted in the tiles becoming dislodged, chipped or broken.  Past methods of fixing tiles directly to the backboard with inflexible materials such as plaster may also cause them to be damaged by the resultant stresses and strains.  It is necessary to replace backing materials that have become brittle and unstable over time with improved systems.  Figure 3 (see left) shows the removal of 36 tiles embedded in a polyurethane foam mounting system used at the V&A in the 1970s.  The backing material had deteriorated to such a degree that it provided insufficient support to the panel of tiles.  Hand tools were used to cut through the brittle foam to expose a layer of aluminium mesh close to the tile backs.  This was eased away from the tiles section by section so that they could be separated and cleaned prior to re-backing on a more suitable material.  After treatment of the individual tiles, the final stage involved bonding them to a lightweight board (Hexlite® 620) capable of providing a rigid and strong support.  The backing technique employed relies on an appropriate preparation of the board and tiles that is easy to implement and time-efficient to provide a safe long-term support for their successful display, whilst remaining easily reversible, should the need arise. [1]
 
A display of architectural ceramics in the newly opened Ceramics Galleries at the V&A is representative of the diverse forms and uses of the tile.  Tile displays in the Medieval and Renaissance Galleries, which opened in November 2009, include tin-glazed earthenware tiles from two Italian sixteenth-century pavements and a group of glazed terracotta ceiling roundels.

For further information contact Fi Jordan, Victoria & Albert Museum, South Kensington, London SW7 2RL  Email: fij@vam.ac.uk  Web: www.vam.ac.uk

References

1. Jordan, F. (2008) ‘The mounting of decorative tile panels for display’, The Conservator, Volume 31, pp.31-41

Materials

Hexlite® 620 (aluminium honeycomb core with a woven glass fibre reinforced skin impregnated with epoxy resin), Hexcel Composites, Duxford, Cambridge CB2 4QA, UK

About the author

Fi Jordan, ACR, is a senior conservator in the Sculpture, Metals, Ceramics and Glass Conservation Section at the Victoria and Albert Museum, London where she has worked since 1990.  She trained in the conservation of ceramics and related materials at West Dean College, West Sussex (BADA/West Dean Diploma 1986) and has a BA (Hons) in the History of Art and Architecture.