Furniture and Woodwork
Churches contain a large number of traditional liturgical timber furniture items, such as altar tables, pulpits, chairs and pews as well as more common items like cupboards, bookshelves and chests of drawers in the vestry. Often of a range of styles and historical periods, the pieces may be made from a range of different species of wood with decorative fittings. Together with woodwork such as panelling, doors and organ cases, these objects will need to be cared for in such a way that is appropriate for the materials.
Causes of damage
The greatest cause of damage to furniture and woodwork is water and a high relative humidity. Spillages from flower vases or coffee cups can damage bare and polished surfaces, most commonly leaving white marks and ‘rings', if they are not immediately mopped up.
Woodwork and furniture react to the relative humidity (RH), i.e. the moisture content of the air around them. Wood shrinks in a low humidity and expands in high levels of humidity. If the relative humidity fluctuates, the timber's repeated shrinkage and expansion causes severe stress to the piece of furniture or woodwork which leads to cracks and splits. The damage will be more severe for more complex pieces with veneers and inlays.
Figure 1 Damaged woodwork due to fluctuating humidity
As temperature and relative humidity are closely linked, no furniture or woodwork should be exposed to a localised source of heat, as this will lower the RH considerably. High RH and the ensuing expansion cause doors and drawers to jam, the corrosion of nails, metal inlays and fittings and can lead to insect infestations and rot.
Light can cause an irreversible change in the colour of timber as well as in any pigments of its decoration. Pieces which contain marquetry and inlays, or whose colour scheme is significant, should be protected from light. Light can also damage wax polishes and shellac and accelerate their breakdown. Textiles such as seat coverings or hangings will disintegrate under the influence of light.
Some timber species are at a higher risk of damage from woodboring insects than others. In general, infestations of insects and fungi are more likely to occur in damp conditions (i.e. a RH of over 70%) and at the undisturbed and unpolished backs of furniture. Fungi flourish where the air circulation is inadequate.
Past repairs which have been poorly executed can be unsightly and cause further problems. For example, repairs with mismatched wood are often of inferior quality and the new material has not the appearance or the strength of the original material.
Signs of damage
Signs of past use:
- dents, surface wear, scratches
- stains, wax drippings from candles, water stains
Signs of structural damage:
- cracks and splits
- loosening or displacement of joints or mouldings
Figure 2 Loss of detail
Cracked and loose veneers and inlays can be a sign of an inadequate environment with fluctuating RH and temperature.
The comparison of exposed and protected surfaces may indicate whether the timber has suffered light damage.
Fresh exit holes and insect residue similar to sawdust are signs of an active insect infestation.
Maintenance
Regular and thorough inspections are needed to assess the current condition of a piece of furniture or woodwork. Inaccessible surfaces like the back of a cupboard should also be checked for signs of insect presence. Consult an accredited conservator if you have found signs of recent insect activity.
Generally, the RH should be as stable as possible, especially for complex pieces of furniture and woodwork. A specialist furniture conservator will be able to assess the condition and needs of the individual piece, measure the RH and temperature and give advice on future care and maintenance.
Enclosed spaces such as drawers and cabinets should be regularly inspected and ventilated as RH microclimates may develop which could lead to mould and fungi infestation. Wood furniture standing on a damp stone floor should be placed on pieces of lead-sheeting under each foot. If mould appears persistently in or on a piece of furniture or woodwork it may be necessary to move it.
Furniture should be handled as little as possible as every moving could potentially be damaging. If handling is inevitable the route needs to be planned carefully and cleared of obstructions. Pieces of furniture should be carried at its strongest point. Avoid tipping and dragging them as this will put stress and strain on the legs and feet. Glass and marble table tops need to be carried vertically as they could break under their own weight if carried horizontally.
Do not force jammed drawers or doors open but get specialist help as they may not be sound. Protect surfaces from scratching, wax drippings and water spills as well as during building work and events. Woodwork and furniture should be protected from direct daylight.
Wooden surfaces should only be dusted when necessary and then very carefully, especially near fragile parts. If a piece has previously been waxed or French polished it can be carefully buffed to restore a shine. Wax should only be applied to already waxed items as it discolours unfinished wood, and should only be applied when needed or once a year. Only use polish made to recipes specified by specialist conservators and designed for historic surfaces. Do not use spray polishes or polishes containing silicon as they can damage the surface and leave unsightly residues.
The patina of brass fittings is highly prized as it complements the look of the furnishing and should not be removed. Do not use metal cleaning fluid as it damages the surrounding wooden surface.
November 2007
Further Information
ICON, Care and Conservation of Furniture
(available on the Conservation Register website)
