Furniture should be positioned at least two feet from any heat source,
never directly in front of a radiator or heater. If the furniture has to be
placed near a heat source then some sort of protection should be put in
place, such as an insulated or reflective barrier.
Dust frequently with a soft cloth, and rub up your furniture often to
encourage a hard skin to form and build up a good surface colour known as
patina. Once or twice a year polish thoroughly using a good beeswax based
polish, polish sparingly, and preferably leave overnight, before rubbing
well. Do not use spray polishes, as although they give a good initial
effect, they contain silicon which builds up a sticky surface and a large
proportion of spirit which evaporates quickly, taking with it some of the
natural oils in the timber.
Antique furniture needs to be protected from fluctuations in temperature and
relative humidity which can cause a great deal of damage and is costly to
repair. Many fine pieces of furniture which have survived for centuries in
unheated conditions can suffer major harm in just one or two winters of
central heating. The reason for this is that antique furniture is
constructed from air-dried timber and has a far higher water content than
modern furniture, which is usually made of kiln-dried wood containing far
less moisture. When subjected to low levels of relative humidity, it
gradually gives up moisture to the dry surrounding atmosphere and starts to
shrink and split along the grain. This is aggravated when underlying pieces
of wood used in the construction are laid at right angles to each other and
then veneered on top. The carcass wood moves and the veneer consequently
tears and lifts and pieces may become detached. If this should happen it is
vital that these pieces are kept carefully, ready for replacement.
Other typical dry air problems include cracking, loosening joints (where
animal glues dry out), drawers sticking, and doors warping and no longer
closing properly. Prevention is always better than cure and it is possible
to safeguard antique furniture from dry air damage by investing in a good
humidifier which will help maintain a constant level of relative humidity in
the air during the winter heating season. For a normal comfortable, indoor
temperature you should aim to maintain 50-55% relative humidity. A cheaper
alternative, but much less efficient, is a hang-on radiator humidifier, or
even a bowl of water nearby, with a simple hygrometer to monitor the
humidity in the room.
Another aspect of prevention is monitoring the amount of sunlight that
reaches furniture. A degree of light over a long period can mellow the colour
attractively, but too much will dry it out, perish the surface polish and can
lead to uneven fading. Where possible, turn pieces of furniture around
occasionally to even the fading process and keep curtains drawn on sunny days
when rooms are not in use.
It is wise to make periodical inspections of furniture for
lifting mouldings or veneer (which will sound hollow if lightly tapped), loose
joints, water damage or fresh furniture beetle (woodworm) holes (particularly
around May/June). If repair is required, do go to a reputable restorer: Good
restoration takes time and is unlikely to be cheap, but a botched repair will
not last, will never be satisfactory and could reduce the value of your antique.

Information on care of fine period furniture reproduced by kind permission of
the British Antique Dealers Association