Greenough & Sons win in the 2021 Pitched Roofing Awards.
The renovation of a 17th Century
listed café in the Snowdonia National Park, which incorporated some
"rare" roofing methods using Welsh Slate, has won the contractors a
national award.
Greenough
& Sons, who are based on the Isle of Anglesey, were one of seven
specialist sub-contractors shortlisted for the "Best use of a roof tile
for a heritage roof," category of the 2021 Pitched Roofing Awards.
Their
10-week work on the Grade II listed Y Sospan cafe in the town centre of
Dolgellau in north-west Wales involved the use of mitred hips and
"single-cut" swept valleys which were once traditional to the immediate
area but are now extremely rare to see.
The
project also featured the use of Welsh Slate's Cwt Y Bugail blue grey
slates in random diminishing courses to replicate the coursing of the
original roof which had been coated with bitumen and subject to various
unsuccessful localised repair attempts.
After
the original roof was stripped and recorded, Greenough's head-fixed the
new slates with copper nails onto 50mm x 25mm battens over open rafters
and a total of 210m2 of roof - the main, 40°-pitch area with 8-16" lengths, and a lower-pitched area with 22" lengths.
Greenough
managing director Jon Greenough said: "The slate valleys, having no
lead or any form of flashing, are an extremely difficult detail to get
right, and only the most experienced slaters with local knowledge of
their construction would be able to carry out these features to maintain
the look, and just as importantly, keep the rain out.
"The
random Cwt Y Bugail slates were the perfect match for authenticity. The
best-quality slates gave the slaters confidence in the material they
were using and provided the client with a product of unrivalled
durability."
He added:
"Much time was taken working with the architect and other industry
experts in recording the existing details and ensuring the new roof
replicated the original as closely as possible. The project was
considered a great success by everyone involved, including the cafe
owners."
Architect Rhys
Llwyd Davies explained that the roof was one of the main elements of the
£210,000, year-long renovation of the café, which was formerly the
town's gaol (with the magistrates' court on the first floor) as part of
the Dolgellau Townscape Heritage Scheme - a project funded by The
National Lottery Heritage Fund, Snowdonia National Park Authority, and
Cadw and Gwynedd Council which had identified it as one of three "High
priority buildings" needing attention.
The
works were substantially funded under that scheme, although the café
owners were apprehensive of using the purely traditional approach of oak
pegs with the slates head-bedded in lime, and wanted battens and a
roofing membrane incorporated.
This
was compatible with the objective of the renovation, which was to
renovate the existing fabric, restoring lost architectural features
where that was harmonious with current building use and introduce energy
efficiency measures where appropriate.
Thus,
the slates were fixed onto the battens over a breathable membrane which
still allowed the traditional detailing to be used. The use of the
battens was a particular interest for the listed building consent as
they, rather than laths, slightly raised the roof's surface.
Head
lap was approximately one third as the work moved up the roof. Roof
abutments with parapet walls and chimney abutments required the use of
lead soakers and cover flashings, sometimes concealed to replicate the
traditional appearance.
Rhys
Llwyd Davies said: "The original roof was a random diminishing-course
slate roof with regional detailing including mitred hips and slated
Welsh valleys. The design team worked together to reach a solution where
large slates were used on the lower pitch, with an increased head-lap
that provided both an improved solution against wind-driven rain but
also replicated the former appearance.
"Welsh
Slate were able to provide a product closely resembling the former
roofing slates, also supplying the varying widths and lengths required
to reinstate the roof installation. They were the best match for this
historic listed building and a long-lasting material to satisfy the
performance requirements. Sustainability was not a major factor in the
decision making but as a long-lasting material we hope that it will not
need to be renewed for a long time."
He
added: "We regularly specify Welsh Slate and learned of the opportunity
to specify varying widths and lengths during an office CPD session. The
client is more than satisfied with the slating works and feel it
enhances their property."
Welsh
Slate sales/technical manager John Owens said: "Our involvement with
Rhys Llwyd Davies and Greenough & Sons Roofing early within the
project phase allowed time for the special random diminishing Cwt Y
Bugail slates to be produced to specifically meet the requirements of
the building.
"The
intricacies of the very traditional detailing, which have not been used
for hundreds of years, require craft skills and an understanding of how
slates work. Throughout the roofing works we liaised with Greenough
& Sons on site to ensure any requirement for special-sized slates
were met.
"It is a pleasure
to be involved in such interesting and challenging projects which are
specified and carried out to the highest standards."
As
well as the roof, the rest of the property was also renovated,
including re-pointing with hot-lime mortar, repairing windows,
installing cast iron rainwater goods, and introducing a consistent
scheme of signage to advertise the building's use.
The winners of the 2021 Pitched Roofing Awards were announced in a virtual ceremony on February 26th.
The
judges said: "An outstanding job that everyone involved in can be proud
of. This project shows exceptional workmanship and true heritage works.
It highlights great use of natural slate with some very traditional
detailing. The overall appearance with stone walling looks fantastic."
