Page 27 - Historic Churches 2013

BCD Special Report on Historic Churches 20th annual edition 27 CATHEDRALC O M M U N I C A T I O N S
MAINTENANCE AND INSPECTION
Churches that fail to carry out regular
maintenance are likely to face the largest repair
bills, and The National Churches Trust Survey,
published in 2011, found that approximately one
in four churches that do little or no maintenance
are already in poor or very poor condition.
Gutters should be cleared after the
autumn leaf-fall, and downpipes checked
to ensure that they are flowing properly.
Any obvious problems in the roof can be
identified at the same time, and a cursory
inspection of the interior can highlight any
obvious problems. Key requirements are:
• high-level access – if roofs are not
accessible from a staircase, a small mobile
cherry picker may be hired or a rope-access
specialist may be contracted to carry out
the work
• specialist expertise – the contractor must
be familiar with traditional construction
methods and materials, and their expected
performance
• supply of materials – a stock of
appropriate materials must be available for
carrying out minor repairs, whether kept
on site (old roof tiles for example) or by the
contractor (such as lime mortar to match
the existing, stainless steel fixings, etc)
• regularity – a cyclical maintenance regime
is essential, with annual gutter clearance
and other routine work as specified by
an architect or surveyor, and preferably
managed under contract with a local or
regional specialist.
Most historic places of worship are given
a more thorough survey every five years
by an architect or surveyor who is trained
in conservation work. This ‘quinquennial’
inspection, if carried out well, will provide
a useful guide to those areas of fabric that
are most at risk of failure. The occasional
slipped slate, for example, may indicate that
the fixing nails are rusting and that the roof
needs to be re-laid. In the event of a leak or
the appearance of an unexplained damp patch,
the inspection report should be consulted.
ROOF COVERINGS AND FLASHINGS
Unless a patch of damp is clearly related
to a particular feature that is known to be
vulnerable (a patch of damp immediately below
a leaded light window, or a blocked downpipe
for example) the roof is the first thing to
check whenever and almost wherever damp
is found. The second is gutters, hoppers and
downpipes, but also look for defects in pointing
and projections that might need flashings.
Until the later Middle Ages, thatched
roofs predominated in rural areas, and often
in urban areas too. However, as the most
important building in the community, churches
were usually the first buildings to be reroofed
with more durable materials. Slates (including
‘stone slates’) were commonly used to roof
churches in areas where the stone was fissile,
while clay tiles became common in other areas.
In their simplest form these materials were
used in much the same manner as thatch, with
broad eaves shedding rainwater clear of the
walls below, without gutters or flashings.
Sheet lead was the most expensive of the
traditional roofing materials, but also the most
adaptable and durable with a life span of over
200 years. It could be used sparingly, with tiles
or slates, in the form of small flashings where
gaps might arise, such as where the tiles butt
up against a tower. It also enabled complex roof
forms because it could be used as a liner for a
valley or parapet gutter, or as a flashing for an
upstand or abutment. Because it could be laid
on roof slopes that were almost flat, sheet lead
also enabled side aisles to be added to existing
churches without compromising the ceiling
height, and for abbeys, cathedrals and the
most wealthy parishes it gave free rein to the
development of magnificent gothic interiors.
Several other sheet metals have also been
used, particularly since the mid-19th century,
including copper and zinc, and stainless
steel has become a popular choice recently,
particularly for roofs prone to lead-theft.
Where roof-level leaks are suspected and
access is readily available, immediate inspection
may reveal a blocked gutter that can be quickly
and simply remedied. However, where access
requires the use of a cherry picker or access
platform, it is best to co-ordinate access with
a visit by the inspecting architect or surveyor
in case more complex problems emerge.
Specialist maintenance firms can provide cyclical maintenance such as gutter clearance and lime pointing. This
cherry-picker retracts to the width of its tracks, enabling it to access most churchyards. (Photo: Forrester Access)
A rare example of thatch on the Quaker meeting
house at Come-to-Good, Cornwall (c1720): here the
stone plinth of the cob walls is protected from erosion
by a French drain
A stone-slate roof over a church porch in Wiltshire:
historically, pitched roofs often did not have gutters,
relying on good ground drainage to avoid erosion to
the base of the wall
A new lead roof over the 15th-century south aisle of
a church in Somerset following its second lead theft
(Photo: Chedburn Dudley)