Welsh Slate Roofing
Welsh Slate is recognised as the best quality roofing slate in the world, and will give you a roof that will last more than a lifetime.
This is because its extraordinary geology gives it unique physical properties which, when combined with generations of skilled quarrymen, create a roofing slate which has been tested over the centuries by the harshest climates imaginable. Available in three thickness grades: Capital; County; and Celtic; to suit the projects requirements. If you need help in understanding the precise benefits a Welsh Slate roof will provide then please call us - we'll be happy to explain more.
Why the unique geology of Welsh Slate makes it the best natural roofing slate
Welsh Slate was laid down as a sediment some 550 to 470 million years ago, heated and compressed by the same huge tectonic forces that created the Snowdonia mountain range. The resulting unique raw slate material contains no reactive minerals and it is this, combined with its ability to be split into very thin flat sheets, that make it the ideal roofing slate. This is because it is light weight, extremely durable and has a natural beauty which only gets better with time. This is why Welsh Slate has been the roofing choice of the world for centuries.
Welsh Slate roofing product is only available from three quarries, each quarries product retains the unique physical characteristics but has its own individual, distinctive natural colouring; Penrhyn® - a Heather Blue slate, and Cwt-y-Bugail - a Dark Blue Grey slate and Ffestiniog - a Blue Grey slate.
The beautiful colours of Welsh Slate Roofing
The subtle and elegant colours of the Penrhyn® Heather Blue slate, the Ffestiniog Blue Grey, and the Cwt-y-Bugail Dark Blue Grey slate, are further enhanced by the distinctive natural texture of each slate. This creates an added dimension to any roof whilst the combination of colours can be used to create a pattern or subtle contrast in a design.
The aesthetic qualities of Welsh Slate are combined with the material’s natural durability and resistance to weather and temperature, making slate superbly adaptable and ideal for all environments.
Heather blue slate
Penrhyn® Heather Blue slate, known also as Bangor Blue and Penrhyn® Purple.
This is produced from a fine-grained slate deposit laid down over 500 million years ago in the Cambrian period and comes from the Penrhyn® quarry. Set in the heart of Snowdonia, it's one of the largest slate quarries in the World, and has been in commercial production for over seven centuries. The properties of the Penrhyn® slate allow it to be split into thin sheets but still retain its strength and unparalleled durability.
Penrhyn® slate comes in three thickness grades: Capital, County, and Celtic, to suite each design, to suit specific roofing needs.
Dark blue grey slate
Cwt-y-Bugail Welsh Slate is dark blue grey in colour with a distinctive texture which makes it a popular architectural material.
This is produced from the Ordovician slate beds laid down over 470 million years ago and comes from the Cwt-y-Bugail slate quarry in Ffestiniog, North Wales. It has been producing slates from 1840, and is currently the highest industrial site in the UK. The slate has a distinctive banding known as relic bedding and gives an extremely uniform unfading appearance on the roof.
Cwt-y-Bugail slate comes in three thickness grades: Capital, County, and Celtic, to suit each design, to suit specific roofing needs.
BLUE GREY SLATE
Ffestiniog produces a beautiful blue-grey slate with a smooth riven texture.
Located in the heart of Blaenau Ffestiniog in North Wales, it has been producing slates from 1818 and was formed by the Ordovician slate beds laid down over 470 million years ago. Ffestiniog Welsh Slate characteristically produces a thin uniformed slate with less texture than Cwt-y-Bugail, our quarry located nearby.
Ffestiniog Welsh Slate comes in three thickness grades: Capital, County, and Celtic to suite your projects specific roofing needs.
Welsh Slate Roofing Manufacturing Process
The manufacturing of Welsh Slate roofing remains a hand-crafted process using traditional skills and techniques developed over centuries. This is carefully combined with modern production processes to ensure all our roofing slates are of the highest standard. Slates are then dressed to their final size with traditional chamfered edges, graded for thickness and packed for despatch.
The focus of production is on the core sizes (Penrhyn; 500 x 300 mm, 400 x 250 mm & 300 x 200 mm. Cwt-y-Bugail; 500 x 250 mm, 400 x 250 mm & 300 x 200 mm) (Ffestiniog; 500 x 250 mm, 400 x 250 mm & 300 x 200 mm) but it has the flexibility to produce bespoke sizes to order.
Welsh Slate Roofing thickness grades
Welsh Slate roofing product is available from three quarries, Penrhyn (Heather Blue/purple slate), Ffestiniog (Blue Grey) and Cwt-y-Bugail (Dark Blue Grey slate), in three thickness grades: Capital, County and Celtic to suit the project requirements. If you need help in understanding the precise benefits a Welsh Slate roof will provide then please call us - we'll be happy to explain more.
Capital Grade Welsh Slate
Capital Grade is the thinnest production thickness at Welsh Slate at 5.5 mm.
Only limited parts of our quarries will make this slate with its fine-grained riven surface. The thinness of the slate gives a flat uniform finish to the roof and was traditionally the material transported to the more distant markets such as continental Europe and even as far away as Australia and New Zealand.
County Grade Welsh Slate
County Grade is the main production thickness at Welsh Slate at 7 mm thick.
The surface texture is similar to the Capital Grade, but the slightly thicker leading edge gives more focus to the slate on the roof. Traditionally sold in the Midlands and North West of England, it is now sold widely across the world.
Celtic Grade Welsh Slate
Celtic Grade is the thickest of Welsh Slates production at 9 mm.
As its name suggests, its natural home is on the roofs of buildings facing the prevailing westerly winds in Ireland, Scotland and Wales. The more textured surface and thicker leading edge give the slate a more rural appeal but the Celtic Grade slate does find its way into city centres, where it can be used to make a statement: There is no doubt that this is a natural slate roof.
Benefits of Welsh Slate roofing
It's Welsh Slate's unique geological factors which makes Welsh Slate unlike any other natural roofing slate available in the world.
Where other slate quarries and producers make roofing product, they cannot have the natural qualities of Welsh Slate, which is probably why they have multiple standards, making it confusing to identify the precise durability and quality of the product on offer. Welsh Slate roofing has only one standard - the very best - any slate that does not make the grade does not become a roofing slate.
- Aesthetically pleasing - its natural tones work with any colour pallet
- Colour-fast - your roof colour will look as good in 100 years as it did the day it was finished
- The most durable slate in the world - with a useful and productive life of more than 100 years – guaranteed
- UK manufactured by highly skilled quarrymen - which means only a low level of on-site grading is required, saving time and money
- Unaffected by normal extremes of temperature - ideal for areas with harsh night frosts and fierce daytime sun
- Highly resistant to acids, alkalis, and other chemicals - highly practical properties that make it an exceptional roofing slate
- Large format sizes available - making Welsh Slate roofing slate much desired for heritage and prestigious projects
It is the only roofing slate to have a lifespan measured in centuries.
Making Welsh Slate the most durable slate in the world, with a useful and productive life of more than 100 years – guaranteed.
Latest News and Case Studies
Roofing
WELSH SLATE HELPS TO BRING HISTORIC CHURCH BACK FROM THE BRINK
An £8 million project to rescue one of central London’s most significant churches from Historic England’s Buildings at Risk Register is now complete, and topped with Welsh Slate.
Roofing
WELSH SLATE TOPS THE FOREFRONT OF A BUILDING REVOLUTION
The Red House was a blueprint for York’s building revolution as following the Great Fire of London, the Government of the day issued new building regulations, including a requirement that any new houses fronted onto a pavement must be built of brick and/o
Roofing
DM ROOFING & ROUGHCASTING LTD CELEBRATES TRIPLE WIN AT NFRC AWARDS WITH WELSH SLATE
The University of Glasgow project showcases the pinnacle of roofing expertise and the timeless beauty of Welsh Slate. The Cwt-y-Bugail slate, renowned for its durability and aesthetic appeal, perfectly complements the heritage architecture of the universi
Roofing
THREE IMPRESSIVE PROJECTS UTILISING WELSH SLATE HAVE BEEN SELECTED AS FINALISTS IN THE PITCHED ROOFING AWARDS
Lucent, St Andrew's Church and The Roundhouse are battleing it our in the "Best use of slate for a commercial project"
Roofing
FROM COURSES TO HORSES
One of the key factors in choosing Welsh slates was their high-quality natural appearance. We recognised the importance of maintaining the architectural integrity of the church, and these slates perfectly matched the authentic look of the existing roof.
Roofing
WELSH SLATE AWARDS TOTAL HITS THE HEIGHTS
Welsh Slate has added to its impressive award roster by featuring on a host of recent winning projects. Welsh Slate featured in every project using slate that won at the NFRC Roofing Awards 2024 on May 10th.
Roofing
WELSH SLATE HELPS ALL SOULS FROM THE END OF AN ERA TO A NEW ONE
The church is an iconic building, occupying a key position on Regent Street, and is highly visible from the surrounding streets, therefore the aesthetic qualities of Welsh Slate were a major consideration.
Roofing
WELSH SLATE HELPS SHED NEW LIGHT AT AT BRIGHTON DOME
Adjoining the famous Royal Pavilion, the Corn Exchange and Studio Theatre have been refurbished by award-winning architects Feilden Clegg Bradley Studios (FCBStudios) for a 21st Century audience. The Welsh slates were also used on the roof of the Grade II
Roofing
WELSH SLATE IS THE LUCID CHOICE FOR LUCENT
Prior to its development, the triangular site at Piccadilly Circus was a mixture of 13 buildings of different ages, architectural styles, listings, ownerships and uses.
Roofing
WELSH SLATE EARNS A DEGREE OF LONGEVITY AT KING'S COLLEGE
Careful recording of the existing diminishing course arrangement allowed it to be re-established, with discreet additional ventilation provided at the eaves and ridge to improve airflow across the roof void. In addition, the PV panels were laid on top of
Roofing
WELSH SLATE WINS THE HEARTS OF PARISHIONERS, AND AN AWARD PLACE
Largely rebuilt in the early 14th Century with rubble and stone slate roofs, the church is an important landmark with a distinctive (and rare) arrangement of two separate towers
Roofing
DANETRE DOES A WELSH SLATE DOUBLE
The reroof of a community hospital with Welsh Slate not only won the specialist contractor a place in the finals of a national award scheme but also enabled its apprentice roofers to get up close and personal with a Grade II listed project.