Page 112 - The Building Conservation Directory 2013

1 1 2 t h e b u i l d i n g c o n s e r vat i o n d i r e c t o r y 2 0 1 3 T w e n t i e t h a N N i v e r s a r y e d i t i o n
3.3
Structure & Fabric :
Metal,
Wood & Glass
Carved Joinery
The conservation and repair of historic timber carvings
Alan Lamb
Our historic buildings contain an
extraordinary variety of carving on
joinery, from the Rochester choir stalls
of 1227 and the fine wood carving of Grinling
Gibbons (1648–1721), to the interiors of the
Arts and Crafts movement. Carving styles
and joinery components have undergone
many changes but the basic techniques used
in their making have generally remained
remarkably consistent. The technical issues
faced by conservators are therefore generally
the same whatever the age of the carving, but
the ethical issues can be highly contentious,
particularly where the question of whether
and when to replace missing carving arises.
In historic buildings that have remained
in constant use, ongoing small losses to
delicate carvings are almost inevitable. In
this context the replacement of missing
carving is a necessary step if our first
priority is to stabilise ongoing aesthetic
deterioration and preserve a space that we
value highly for its appearance. Different
priorities would apply when considering a
museum piece in un-restored condition,
preserved in a protected environment.
The decision to replace a missing
component in a historic building should
always be a considered one. The question
assumes the conservator has the skill and
sensitivity to produce a carving that matches
the quality of the original and that there is a
good reason for the intervention. In all cases
the decision has to balance the competing
priorities of the aesthetic, historical and
physical integrity of the object in a way that is
appropriate to the object’s setting and use.
Aesthetic and historical considerations
might include the general level of finish
in the room, how much the losses detract
from the original design intention, the
symmetry of the object, and how closely
we can reference the new carving to
existing features or other evidence.
Physical considerations might include
the current use of the room, the condition of
its support, and the state of its environment.
A diagnostic assessment or treatment plan
should always look at the carving in the
context of both the structure it is part of or
attached to, and the fabric of the building that
supports and contains that structure.
Historic construction
techniques AND MATERIALS
Mortice and tenoned frames with unglued
pegged joints and panels were the most
fundamental component in the construction
of screens, wall panelling and choir stalls
in the Middle Ages. The frames could be
decorated with carved or pierced panels and
the jambs could be extended with other layers
of timber to form arches and other carved
decorative features. In 17th- and 18th-century
joinery, doors, reveals, shutters, soffits and
box pews were framed, while architraves,
entablatures and chimneypieces were often of
simple plank or box-frame construction, with
elaborate carving fixed to them with nails or
metal pins. Carved elements could be made up
of several layers glued together, either before
or during the carving process.
The species of timber commonly used in
carved joinery are outlined below.
European Oak Quercus robur
Until the last quarter of the 17th century oak
was by far the most commonly used timber
in carved joinery. Most would be English in
origin but from the mid-14th century onwards
high quality quarter-sawn oak boards known
as wainscot were imported from Europe.
These sawn boards were used for doors,
window shutters and panelling.
Deal (Pine, spruce and fir)
From the 16th century, the term deal was
used to describe any, ready-sawn coniferous
timber imported from the Baltic. Red deal or
yellow deal implied European redwood, Pinus
sylvestris (Scots pine). This is by far the most
common imported species encountered in
carving and joinery. Deal is light, stable, fast
to carve and takes paint or gesso (a fine plaster
bound with size used for gilding and paint
finishes) better than oak.
Scribing a template for replacement carving, New College Chapel, Oxford