Agriculture Reference
In-Depth Information
Figure 90
Replacing cut-moulded
voussoirs to the arched
face of the niche hood.
(Courtesy of Emma
Simpson)
The scallop-shell boss represented a particular challenge because there was
barely enough evidence in the original material to suggest a way forward in its
repair. After discussion, it was felt that it would be in keeping with the spirit of
the building to try to re-establish the outline of the shell. Clay was modelled
directly on to the brickwork to build up the scallop shell outer edge in order
to agree a shape for the new work. Following careful recording and produc-
tion of a drawing all the outer nine bricks were removed. Using paper tem-
plets, brick blanks were cut which had to fit accurately together in order to
avoid any opening up of joints once material was carved into and to replicate
the very fine joints of the original. These blanks were then marked up with the
proposed lines of the ribs and scallops, matching up as far as possible with the
original lines, although these were eroded in many places. The bricks were
then carved and dry laid before setting in a compound of whiting and shellac.
Once the whole piece had hardened off, fine-tuning of the carving was pos-
sible and mortar repairs were carried out to build up the eroded ribs (Fig. 91).
The hood of the niche was dry brushed and the loose blisters were removed.
This instantly improved its appearance and stopped them from providing
pockets for grime or frost. A more systematic but gentle clean was carried out
using minimal water and soft bristle brushes. Following this treatment, it was
decided to leave the hood. Further rubbing back could have opened up joints
and weakened the fragile nature of this element of the niche.
The use of mortar repairs was kept to a minimum, as it was feared it could
detract from and deaden the effect of the gauged work. However, in small
areas, mortar repairs were used to protect a brick that had a relatively minor
defect that could lead to further decay. The basic mix used was:
5 parts hydraulic lime (St. Astier 3.5)
8 parts brick dust (original discarded Eltham rubbers)
