Issue 42 summer 24 web - Flipbook - Page 106
Weather on
the Weatherings
Heritage Stone Access are specialists in conservation stonemasonry led by cathedral-trained
stonemasons. Their ability to access areas at height with IRATA (Industrial Rope Access Trade
Association) trained technicians enables them to both routinely inspect and maintain heritage buildings
to keep them safe, and to respond rapidly to emerging issues such as stone fall or displacement. Another
benefit of rope access is that it is non-intrusive, where scaffolding may be, and allows bespoke localist
conservation repair works to go ahead without hugely interrupting day to day use of the building.
These last eighteen months have been the wettest on
record since records began in 1836. As winters are
becoming warmer, they also become wetter. And as all in
the conservation building industry understand, shedding
rain and water management is one of the most important
systems in the upkeep of heritage properties.
Standing water saturates into stone. It can wash out the
matrix of the material, and dissolve salts that then appear
on the faces of the stones as efflorescence, that is surface
crystallisation of the salts. Less soluble salts may crystallise
within the pores of the stone and start to break apart the
material - this is termed cryptoflorescence and it causes
powdering and blistering of stonework.
Stone tends to be most badly damaged when there is
repeated wetting and drying, causing cycles of crystallisation. This tends to happen where water is able to pool
where weatherings have not been maintained or where
drains and gutters are blocked. Management and maintenance of these details is key to upholding the quality
materials that heritage buildings are built from.
Two solutions help manage water ingress on stone
buildings. The first is the upkeep of the weathering details,
and the second is the upkeep of the drainage details.
Picture, Coddington Church (Credit Jan Sedlacek)
Heritage Stone Access as specialist stonemasons are able
to carry out fingertip surveys of areas at height, and report
on the condition of weathering details such as spires,
hooded arches, string courses, pinnacles, gargoyles and
coping stones. They are able to assess defects, and also
repair, re-carve and replace stone detail. On many heritage projects, they routinely carry out necessary pointing
to maintain the integrity of the stonework. For example
on vertical joints within cornices, string courses, spire
stones and other weatherings that get washed out over
years of exposure. Each inspection comes with a report by
a qualified and experienced stonemason carrying recommendations that are graded in terms of priority for the
building. Conducting regular inspections allows for priority works to take place in small phases of conservation repair. Carried out on local areas of the building can save
large amounts of damage in the future. Bespoke localised
repairs without the use of a scaffold tend to be able to fit
within budgets and events.
When small phases of works are surveyed, documented
and carried out in this ‘little and often’ way by specialist
stonemasons, it enables a cost-effective approach that
addresses other issues at the same time, such as high level
