Page 94 - The Building Conservation Directory 2013

9 4 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
3.2
Structure & Fabric :
Masonry
The Sands of Time
Britain’s building sandstones
Graham Lott
Currently there are around 200
active building sandstone quarries
in Britain, more than enough one
might think to supply current construction
industry needs. However, in the mid 19th
century there were more than 850 quarries
supplying building sandstone, as well as
many more unrecorded small producers
meeting local vernacular needs. How has this
dramatic decline in the production of building
sandstone impacted on our building industry?
The most fundamental change has been to
restrict the choice of sandstones available,
particularly for conservation repair and new
build projects.
Sandstone beds (see map, above)
occur in all the main geological systems
cropping out across Britain (Precambrian,
Cambrian, Ordovician, Silurian, Devonian,
Carboniferous, Permian, Triassic, Jurassic,
Cretaceous and Tertiary successions).
Although not all beds produce suitable
building stone, sandstones from each of these
geological systems have been used for building
stone to a greater or lesser extent.
In general, most early quarries began as
sources of vernacular building stone supplying
a few local projects, but by the 19th century
a small proportion had grown to become
important national sandstone resources,
supplying towns and cities far beyond their
immediate vicinity. Outside London, in the
south of England, the Midlands, Wales and
in the north of Britain, our most recognisable
historic buildings and structures are
commonly constructed using local sandstones,
many of which are now no longer quarried.
The past success of the building sandstone
industry has in more recent times been
tempered by a marked decline in production
in some areas. Many important sandstone
resources have already been lost. One of the
best documented examples is the Craigleith
Sandstone, originally quarried and used
extensively in the City of Edinburgh in the
18th and 19th centuries. Made inaccessible by
redevelopment around the original quarries,
the sandstone has not been available in the
market place for several decades (Hyslop 2004
– see Recommended Reading). Elsewhere
in the UK, the problem is perhaps less well
publicised but equally acute. The lack of active
quarries has meant that in sourcing stone
for repair and new build projects, architects
frequently have to consider using sandstones
quite alien to the local area. Stone matching
in the heritage field is particularly affected,
as it is becoming increasingly a case of using
those sandstones that are currently available,
rather than selecting a sandstone that best
Church Horbury, West Yorkshire: Local Carboniferous sandstone displaying
natural cross-bedding to great effect
Cretaceous sandstones
Jurassic sandstones
Triassic sandstones
Tertiary sandstones
(small isolated occurrence)
Permian sandstones
Carboniferous sandstones
Devonian sandstones
Silurian sandstones
Ordovician sandstones
Cambrian sandstones
PRINCIPAL SANDSTONES OFTHE UNITED KINGDOM