National Trust Trusts Welsh Slate With An Apian Issue
50,000 rare wild bees get a new Welsh Slate roof over their heads.
The reroof, with Welsh Slate, of a historic National Trust manor house with ornamental gardens overlooking the Llŷn Peninsula in North Wales, has created quite a buzz locally.
For five swarms of some 50,000 rare Welsh black bees - Britain’s “original” honey bees - had to be temporarily relocated while the work was carried out at picturesque Plas yn Rhiw where they had lived in the roof space – and oozed honey through cracks in the walls - for as long as anyone can remember.
Notorious for their bad tempers, they were retrieved by honey bee specialists SwarmCatcher and relocated to hives nearby while the refurbishment of the 17th Century property was carried out, then were returned to Plas yn Rhiw’s orchard from where they were allowed to find their own way back into their former home.
The new roof areas of more than 7,000 brand-new 600mm x 300mm 7mm Penrhyn County and 400mm x 200mm and 250mm x 200mm 9mm Penrhyn Celtic slates feature a total of two pitches and four valleys over 219m2. A roof survey had identified these Welsh slates as the closest match to the existing ones. Access for the wild bees was maintained via small gaps around the eaves and under the slates.
Slates that were reclaimable, even after more than 200 years on the roof when the then-owner Captain Lewis Moore Bennet remodeled the house, were re-used on other roof elements. As well as the new roof, this latest refurbishment of Plas yn Rhiw included an exterior facelift, repointing, repairs, and renovation of windows, fascias and rainwater goods.
While Plas yn Rhiw lies in its own micro-climate on the Llŷn Peninsula, it generally being milder, its biggest challenge during the winter months is high winds and heavy rainfall. Over the past 200 years the roof has been cared for and repaired in small patches but recent severe weather caused it to need a complete re-roof.
Dewi Hughes, chartered architectural technologist at Dewis Architecture, explained that Welsh Slate needed to be used as it was a Grade 2* listed property for the National Trust. But he also said the fact it was a Welsh product played a part in its specification.
“Welsh Slate, being a local product, had been used on the property historically, sourced from Penrhyn Quarry in Bethesda. Welsh slate is the best slate in the world in terms of quality, longevity and weathering characteristics,” he said.
National Trust Cymru building surveyor Clive Parkinson added: “Welsh Penrhyn slate was specified on a like-for-like basis due to its excellent quality over other slate products. The National Trust have used Penrhyn slate for reroofing for many years on our listed and non-listed properties, due to its ability to provide a 100-year lifespan.
‘It’s simply better than other products, plus the fact we always specify local products where possible to save on the carbon footprint. There is a mixed bag down the Llŷn in terms of slates used, ranging from Ffestiniog/Penrhyn and others. In my experience, Penrhyn slate product is the best in terms of getting longevity to achieve a 100-year lifespan.”
The reroof, on the front pitch of the main duo-pitched roof and its canopy/porch, and two duo-pitched rear outrigger roofs, with pitches between 30-35°, was carried out by local contractor Jones a Williams Cyf. Welsh Slate is guaranteed for 100 years, but as can be seen at Plas yn Rhiw, has a shelf life considerably longer.
The Welsh black bee is a locally named member of the European black bee family. In Britain, they were largely wiped out by a virus a century ago but were rediscovered in parts of Wales, Cornwall, Yorkshire and the Isle of Man.
Plas yn Rhiw was rescued and lovingly restored in the 1930s by three nature-loving sisters – Eileen, Lorna and Honora Keating. Before gifting it to the National Trust in 1952, they stipulated the building’s apian residents must always be safeguarded.