WELSH SLATE LTD

PENRHYN QUARRY
BETHESDA
BANGOR
GWYNEDD LL57 4YG

Tel: 01248 600656
Fax: 01248 601171

Company Logo

Suppliers of: Roofing slates, Slate cladding, Slate paving, Walling, Sills and copings, Landscaping, Aggregates, Slate tiles for flooring, Fire surrounds/hearths, worktops/counters

Welsh Slate Ltd is the world’s leading supplier of high quality slate and supplies the UK construction market with highly durable roofing slates, facade cladding, slate paving, walling, sills and copings.  For internal projects, Welsh Slate manufacture and supply slate tiles for flooring, fire surrounds, bespoke kitchen worktops and counters.

Environmentally Responsible

Welsh Slate’s Penrhyn quarry has been supplying slate worldwide since the 13th Century and has a long tradition of being specified by architects, and our client base also includes leading developers and interior designers. As a result of our work we are committed to conducting our business in an environmentally responsible manner by minimising the environmental impact and promoting sustainable development within its operations and services.

CPD Seminar

This seminar is designed to help architect and specifiers to understand the manufacturing process and the potential applications of Welsh Slate as a building material. It will explain the advantages and problems with slate and clarify the difference between differnent slates from around the world. The presentation will inform delegates of the variety of applications for Welsh Slate and provide information on the standards, accreditations, classifications and fixing methods.

CPD Factory Tour

The two hour tour will demonstrate the current slate quarrying and production processes while in addition giving you some hands on experience of working with a natural product. For enquiries or to arrange a CPD please telephone our sales office on the telephone number above or alternatively click here and fill out an enquiry form.

Our wide range of products include:

Roofing Slate

Welsh slate is proven to out last any other roofing material and is guaranteed to have a productive life in excess of 100 years. Colour variants are available and can be supplied up to 1.2 meters wide.

External Slate Paving

Welsh slate is available in a range of thicknesses from 30mm to 100mm and a variety of colours and textures to suit any application. Slate paving is frost-resistant and slip resistant certified to BS EN1341:2001

Welsh slate is weather and waterproof, unaffected by atmospheric pollution, sea air and organic growth and is colour-fast and non-fading, even in UV light. Certified and tested to BS EN 12326 - 1:2004

Welsh Slate Flooring

Welsh slate is a hard wearing natural floor tile for use in both domestic and commercial applications. The material is highly durable and easily maintained. As an unpolished floor tile Welsh slate is slip resistant to BS EN 1341:2001.

Facade Cladding & Masonry

Welsh slate facade cladding is ideal for use on either internal or external cladding products and is an ideal material for use on ventilated rainscreen cladding. Welsh slate masonry units are available in course heights of up to 180mm and to random or specified lengths with pillared or sawn face.

Our facade cladding is supplied to bespoke sizes and has been installed in diverse applications such as public buildings and churches to industrial and commercial developments and residential properties.

Stone Walling

Welsh slate makes an ideal walling product and is available as either quarried rustic walling with a naturally exposed face or as a smooth faced pillared walling face.

Sills & Copings

Welsh Slate can supply bespoke slate sills and copings for both refurbished and new-build commercial and residential properties and are available from stock and to order.

Aggregates and Landscaping

Slate aggregate has many outstanding technical properties. Welsh slate is available as a decorative aggregate in three colours. Our slate aggregate is also supplied for use in precast and ready-mixed concrete, road building and civil engineering.  Slate granules are used to produce bituminous roofing felts and artificial slate roofing tiles. We also supply Slate feature landscaping stones and monoliths.

Slate Fire Surrounds and Hearths

Welsh slate is the ideal stone for fire surrounds and hearths for solid fuel and wood burning stoves as well as open fires. Bespoke to your specific requirements, these fittings can be supplied in a range of colours, finishes and edge detail.

Slate Kitchen Worktops & Counters

Welsh Slate makes a beautiful and practical material for worktops and counters, combining very low liquid absorption levels with a luxurious warm feel to the hand.  The material is supplied as a completed wipe-clean slate worktop to consumers and contractors’ projects or as unfinished or polished scant to worktop manufacturers.

Further technical information, image galleries and product specifications are available through the Welsh Slate website or via the BPi Download Library.

ACCESS FLOORING Slate .
AGGREGATES Slate .
ARCHITECTURAL Stone Slate
CILLS Slate .
CILLS Slate Welsh Slate
CLADDING TILES Stone Slate
CLADDINGS EXTERNAL Cut Facing Stone Slate
CLADDINGS EXTERNAL Riven Slate Surface .
CLADDINGS EXTERNAL Slate .
CLADDINGS INTERNAL Riven Slate .
CLADDINGS INTERNAL Slate .
COPINGS Slate .
COPINGS Slate Welsh Slate
CRAZY PAVING Slate .
DRY STONE WALLING Slate .
FABRICATIONS Slate .
FIRE SURROUNDS . .
FIRE SURROUNDS Natural Stone Welsh Slate
FLAGSTONES Slate .
FLOORING Natural Stone Flooring .
FLOORING Natural Stone Flooring BS EN 12058 CE Marked
FLOORING Riven Slate .
FLOORING Slate Flooring .
HEARTHS AND BACK PANELS Welsh Slate Hearths .
KITCHEN WORKTOPS . .
KITCHEN WORKTOPS Curved Worksurfaces .
KITCHEN WORKTOPS Natural Stone .
KITCHEN WORKTOPS Slate Welsh Slate
LANDSCAPING Aggregates .
LANDSCAPING Paving .
PAVING SLABS Patio Natural Slate .
PAVING SLABS Riven Slate .
PAVING TILES Welsh Slate .
RAINSCREEN SYSTEMS Slate .
ROCKERY STONE Slate .
ROOF VENTILATORS Flush Slate .
ROOF VENTILATORS Welsh Slate Bat Access Units
ROOFING Slate .
ROOFING SLATES . .
ROOFING SLATES BS EN 12326 CE Marked
ROOFING SLATES Natural Stone .
ROOFING SLATES Natural Stone ASTM S1 Classified
ROOFING SLATES Natural Stone BS 5534
ROOFING SLATES Natural Stone BS EN 12326-1 CE Marked
ROOFING SLATES Natural Stone BS EN 12326-1:2004 A1-S1-T1
ROOFING SLATES Natural Stone Heavy Slate
ROOFING SLATES Natural Stone Heritage and Conservation Applications
ROOFING SLATES Natural Stone Heritage and Conservation Applications England
ROOFING SLATES Natural Stone Heritage and Conservation Applications Scotland
ROOFING SLATES Natural Stone Heritage and Conservation Applications Wales
ROOFING SLATES Natural Stone Low Pitch Roofs
ROOFING SLATES Natural Stone Welsh Slate
ROOFING SLATES Roof Weathering Slates .
ROOFING SLATES Strip Slates .
ROOFING SLATES Ventilator .
SLATE Paving .
SLATE Rustic .
STONE FLOORING See Also FLOORING: Natural Stone Flooring .
TILES, FLOOR Riven Slate .
TILES, FLOOR Slate .
TILES, WALL Slate .
WALLING Riven Face .
WALLING Sawn Face .
WALLING Slate .
WALLING Slate Pillared Slate
WALLING Slate Welsh Slate
WINDOW SILLS See Also CILLS: .
WORKTOPS Welsh Slate .

Welsh Slate scores a double at a unique church in Everton

September 2019

Welsh Slate scores a double at a unique church in Everton

Manufacturer replaces unique slating system at the famous St George’s Church.

One of two unique cast iron churches in Liverpool is enjoying a new lease of life after a second phase of reroofing has been completed with Penrhyn Heather Blue slates from Welsh Slate.

The unique patent slate roofing project will help safeguard the Grade 1 listed St George’s Church in Everton which is on the Heritage at Risk register.

The church, which was built in 1814, is one of only two remaining world-renowned cast iron frame churches, both in Liverpool, the other being the 1815 St Michael’s in the Hamlet, Aigburth, otherwise known as the “Pink Church”.

Both buildings were designed and built by Mersey Iron Foundry owner John Cragg and the accountant-turned-architect Thomas Rickman. They developed a novel system to prefabricate church buildings and patented the iron and slate construction details.

The Phase Two reroof comprised large “modular” 20mm riven slabs of Welsh Slate’s Penrhyn Heather Blue slates ranging in size from 750mm x 850mm to 1,450mm x 850mm, employing a single-lap and laid almost flat, at a very low pitch of 7˚.

These were originally pinned onto the deep cast iron rafters set onto a hessian and putty sealant, employing an overlapping protective capping slate at all butt joints. A second ‘sarking’ layer of slate was employed, resting on the lower lip of the iron rafters, and these formed the underside of the ceiling. This created a cavity between the two layers of slate, effectively forming a very early rainscreen system.

Described by English Heritage as one of the earliest and most thorough uses of industrial materials in a major building, the churches are two of the first, and only remaining examples, of prefabricated and modular architecture in the world, hence their Grade I listing. The development of this cast iron architecture is believed to have paved the way for multi-storey framed buildings and ultimately the skyscraper.

Finlason Partnership Ltd (FPL), specialists in the restoration of historic buildings, were appointed as church architects for both churches, and are overseeing a series of repair works valued at more than £1.25 million. These tackle almost every aspect – roofs, towers, re-pointing, window repairs, internal redecoration and heating systems.

The unique, almost flat patent slate roof at St George’s had suffered from continual water ingress following the breakdown of the “sealing putty” and damage to the cast iron structure and decay had reached a dangerous state. Investigation by FPL highlighted the need for modern detailed design to respect the historic fabric and the original principles of the iron founder and architect.

Due to financial limitations, FPL proposed a two-phase strategy for replacing the roof, the first phase focusing on the nave roof which was in the worst condition, and the second phase reinstating the chancel and four porch roofs.

FPL designed a solution to the inherent faults (primarily, the putty degrading) and Phase One completed in June 2015. The nave was reroofed with a complete new treated timber substructure incorporating drainage zones, insulation and a new inner waterproof membrane with timber members supporting the slate panels.

The new overlapping slate panel detailing, associated joinery and metalwork was developed in close collaboration with Welsh Slate to respect the original intentions and aesthetic but with improved weathering provided by a special sarking layer and improved ventilation.

Phase One sub-contractors RoofAbility employed a modern system of stainless steel fabricated clips and fixings designed by FPL to support the load of the slate and resist movement.

They used a variety of Welsh Slate’s Penrhyn Heather Blue 20mm riven slates, ranging from 1,350mm x 950mm to 650mm x 200mm, as the capping slates, over 300m2 of one half of the roof. The Welsh slates on the other half were re-used and those which could not be re-used were recycled.

FPL then helped the church to secure a further £230,000 of funding to undertake the Phase Two reroof which was carried out by Manchester-based Mather and Ellis stonemasons. This phase saw the replacement of the remaining roofs – those at low level to the four corner porches and the chancel – employing similar construction details as devised for Phase One.

Mather & Ellis took almost nine months to lay the 75m2 of new slates onto the timber rafters with felt under. Additional timber noggins were added between the rafters to form a grid and ensure each slate was picked up on all four edges.

The slates were fixed with bespoke stainless steel brackets which hooked under the front edge and were screwed down to the top timber grid underneath. Expanding foam tape was then used to seal the slate at the top edge. Perps were made weathertight with a narrow slate slip or cover slate.

Phil Duerden of Mather & Ellis said: “Access was fairly easy, through an old gate opening onto St Domingo Road, but the project was very challenging to complete. The roof is an unusually low pitch and the slates are unusually large, plus the jointing pattern is unusual in that the perp joints all line up, rather than being staggered as per a traditional roof.

“The roof system required hundreds of hours of labour to get up on and installed perfectly level. The slates themselves weighed over 100kg each and each one had to be physically manhandled into position, up a pitched roof, without breaking any of the extremely large slate pieces.

“But the large slate sheets matched the dimensions of the originals exactly, and also the colour and consistency of the nave roof done in a previous phase of work. The new roof panels should ensure the roof remains watertight for many years to come.”

Conservation-accredited architect and managing director of the Finlason Partnership, Alex Finlason, said: “With first-class early cooperation, prior to the start on site by Mather & Ellis, appropriately-sized and quality blocks of slate were selected in the Penrhyn quarry ready for cutting to size to create the wonderfully textured Heather Blue hand-riven 22mm slate panels that characterise this beautiful roof.

“This extremely challenging project was completed on budget and within the time constraints. As conservation-accredited architects, we are expert in the use of Welsh slate and cast iron in buildings but the support given by Welsh Slate on this project proved invaluable to reconstructing these unique roofs for future generations.”

He added: “The only unfortunate thing is that, located at the highest point in a 50-mile radius, only the seagulls get to see the new roof of this fine historic building. That is apart from the church wardens who retrieve the many footballs that come to rest on the roofs from over-enthusiastic locals. Even this aspect was considered, by the ‘doubling-up’ of the supporting structure to prevent the cracking of slate panels under foot.”

FPL maintains that while St George’s is widely acclaimed as the world’s first ‘iron’ church it would be more fitting to be known as the ‘Iron AND Slate’ church as it is not only an influential and important piece of architecture due to its use of cast iron but integral to this was the widespread use of slate in this composite construction.

“The work at St George’s Church is considered an exemplary project which has expanded the industry’s knowledge on historic roofing techniques and is a template for the training of slate roof professionals,” said Alex.

Work outstanding includes repairs to the lead on the tower roof, masonry, further stone repairs to the window surrounds/tracery and to the stained-glass.

Welsh Slate products help strike the balance between design and crime

September 2019

Architectural products feature on the new HQ of an international crime agency.

Natural slate walling and decorative aggregates from Welsh Slate are bringing a soothing calm to the new headquarters of an international crime agency.

The manufacturer’s Cwt-y-Bugail blue/grey pillared and rustic walling and Cwt-y-Bugail blue/grey pillared and rustic blocks in various sizes, have been used for and around a 232m2 feature waterfall at the new €105 million offices of Eurojust, which combats serious cross-border crime and organised crime within the EU.

The walling and decorative aggregates are part of Welsh Slate’s architectural portfolio of products that also includes flooring and paving.

The new building enables the agency’s Netherlands personnel to relocate from two locations to just the one, in The Hague’s World Forum/International Zone area.

Developed by the Central Government’s Real Estate Agency, the Ministry of Justice and Security, and the municipality, the stringent security measures and complexity of the location required a carefully integrated design solution.

Mecanoo architects have designed a headquarters building that is an elegant composition of two volumes – a high-rise tower and a low-rise plinth on the park side – in which the rhythm of pure white composite façade elements gives the building a timeless, classic beauty. Windows are subtly tilted horizontally or vertically, reflecting both the sky and the surrounding landscape.

Mecanoo designed the landscape as one of undulating dunes with grassy vegetation and wild flowers, in collaboration with landscape architects DS Landschaparchitecten. By incorporating the security requirements within the landscape design, the building has retained an open character.

Inside, visitors are welcomed into a spacious, double-height lobby from which there is a gradual transition from open spaces to more private areas. A wide staircase, overlooking the dune landscape, descends to the conference centre. Higher levels feature contemporary office environments to encourage cooperation.

Eliano Felicio, marketing communications manager for Mecanoo architects, said: “We’re positive about the stone as it delivers the intended atmosphere and most of all responds to the security requirements that such a complex building demands.”

Frans Rombouts, manager for main contractor Heijmans who partnered with de Enk Groen & Golf on the landscaping element, said: “The contract was awarded on the basis of economically most advantageous tender, with the construction quality being a major contributing factor.”

The Welsh Slate walling and decorative aggregates were specified by Heijmans, supplied through Lei Import in The Netherlands, and installed by Roys Maatwerk.

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