"roof beams and trusses timber"

d² Dura Grating Mini Mesh, Dura Profile & Dura Platform 40 | Case StudyDura Composites was engaged by Premier Marinas to work with their engineering company to produce a composite floor structure around their travel hoist supported by large 305mm GRP Dura Profile beams between 6-10m in length. The team chose the GRP material over steel due to its superior performance in corrosive salt-water environments. Unique in the market, Dura Profiles exceed the higher performance E23 grade requirement of the BS EN 13706 standard.Also central to the efficient operation of the washdown and hoist are Dura Grating and Dura Platform 40 flooring made from moulded and pultruded high-performance GRP panels which are unique in design to Dura. The open mesh section utilises 55mm d2 Dura Grating Mini Mesh in dark grey, which facilitates drainage whilst maintaining strength and unrivalled anti-slip properties. The solid surface sections were created using patented d2 Dura Platform 40, which are crankable to create an in-built fall to aid water runoff.

FOAMGLAS® READY BOARD T4+Design Architects: Kohn, Pedersen, Fox Associates – KPF London, Marcus BlanesMain contractor: SkansaConstruction: 2011Application: Compact Roof - FOAMGLAS® Ready Board T4+Finish: Umicore VM ZincThe roof level 41 of the Heron Tower (with a height of 120m) is designed to the most exacting standards for sustainability and efficiency.The building received the BREEAM rating of 'Excellent', with FOAMGLAS® thermal insulation being part of a green and energy efficient building. The roof is composed with FOAMGLAS® READY BOARD insulation and Umicore VM Zinc roofing as a durable finish.FOAMGLAS® insulation has the ability to withstand high structural loads and has developed a special fixing system for metal roofing.Square metal fixing plates are inserted into the upper surface of the insulation and covered with a waterproofing and a separation sheet.This is the perfect system to fully support metal standing seam roofing which is screwed to the metal plates without thermal bridging between the metal roof sheet and the building structure.

Radii’s Pre-Construction Design Department worked closely with architects tp bennett to deliver a number of high-end bespoke solutions at this stunning location in St. James’, London.Working across 58 offices and meeting rooms, our elegant and slimline Parallel 50 and Parallel 84 systems (both Rw 45 dB) with Glide framed sliding doors were used on Level 4 with recessed head track detailing. Detailed manifestation finishes provided vision panels into the internal spaces.For 11 private spaces on Level 5, stunning smoked oak moulded timber doors were installed with PPC aluminium inlaid trim finished to match the glazing tracks. The timber portal door frames were designed to be as deep as the adjacent drywall nibs to create a flush and seamless finish.

Radii manufactured and installed Parallel 50 double glazed partitioning (45dB Rw) with adjoining Parallel 100 (50dB RW) for TS&W’s glazed fronts on the Ground floor and Level 1, including a number of stunning curved glazed elements. Linear 25 single glazed partitions (38dB RW) were used on Levels 2 to 5.Enhanced acoustic timber doors (40dB Rw) in veneered and painted finishes and with adjoining timber pilasters were utilised for the executive meeting rooms and offices.Auto-operated framed glazed pivoting doors, with visible overhead operators mounted on our top channels, were also installed to give easy access to ‘den’ and collaboration areas.Finally, a fire rated package comprising of structural Ei90 fire rated glazed screens was added on Level 5.

Broadleaves, in Boughton, near Ollerton, is the fourth ‘housing with care’ scheme to be opened by Newark and Sherwood District Council. The state-of-the-art scheme has been designed for people aged over 60.There are 30 spacious and accessible apartments designed to meet possible future needs, with features including a wet room and wider doorways.SMART Balustrades were contracted by NMCN to design, manufacture and install their stainless steel balustrade system with oak handrail to 4 stairs as well as 15 stainless steel Juliet balconies, 250m of timber corridor handrails, and a large external terrace with 1600mm high stainless steel balustrade.SMART’s timber balustrade system comes complete with a steel core rail to ensure the balustrades meets the required 0.74kN/m horizontal line load requirements.

Manchester Arena, managed and operated by SMG Europe, is one of the busiest venues in the world, and the largest indoor arena in Europe. A leaky roof, specifically in the area where the existing roof of the arena joined the railway station, was causing real concern and disruption. Following the roof survey, the Technical Team created a bespoke specification, including project specific detail drawings, tapered insulation plans and roof layouts, U-Value Calculations, Wind Uplift Calculations and Condensation Risk Analysis.

With its team of experts in the polycarbonate and roof glazing fields, Twinfix works on developing the best, newest and most cost-effective roof glazing products. A family business, Twinfix has been involved in the polycarbonate roof glazing market for nearly 30 years. This year, Twinfix worked with Principal Contractor AmcoGiffen restoring Pembroke Dock Station. Twinfix supplied its non-fragile roofing system the Multi-Link-Panel to replace the old tired, discoloured glazing at Pembroke Dock Station.

A £40 million investment, 13 roof areas, eight different roof levels, and a steady stream of visiting students to keep happy throughout – the University of Reading (UoR) Library’s complete refurbishment was a large and challenging project spanning three years.Originally opened in 1964 and later extended in 1985, the library’s internal and external revamp was designed to increase space, improve facilities for individual study, provide better access and security across the building, and improve energy efficiency.In addition to a new-build Café extension, a new entrance canopy, a new ground-to-roof level lift and stair core extension – each featuring a new flat roof area – there were also 10 existing flat roof areas refurbished, coupled with the replacement of windows and re-cladding of the building’s exterior.Following a competitive tender based on an outline specification, Owlsworth Roofing, Sika Sarnafil single ply flat roofing specialists, impressed with the level of detail included in their quote and were awarded the contract by main contractor ISG.Roofing:Sika® Sarnafil G410-12 ELF.Sika® Sarnafi G410-12 EL.Sarnavap®-5000E SA.Sarnavap® HD SA.Primer 600.Sikatherm® PIR Insulation and Sarnacol®-2162.

The purpose:Taylor Wimpey’s Eclipse development was the final phase of the large-scale modernisation and renewal strategy for the London Borough of Walthamstow Forest, known as The Blackhorse Lane Action Plan. Eclipse would offer affordable social and private housing via 500 homes in two six-storey apartment blocks.To help satisfy one of the Plan’s objectives- “to ensure new developments incorporate the highest levels of sustainable design and their impact on climate change is minimised”- we installed green roofs on both blocks. As it was the final development phase, space was limited; time was also an influencing factor in facilitating the tight build programme,avoiding delays, and enabling the client to deliver much-needed new homes.Our solutionTo enable fulfilment of the brief, we recommended our HM-40 Paratech Hot Melt Roofing System as the inverted waterproofing base for the green roof. A fully-bonded system, HM-40 is a robust, durable, and highly flexible monolithic, self-healing hot-melt waterproofing system for protected roofs, green roofs, terraces, and podium decks with a 40-year durability statement. In addition, it is firerated for unrestricted use when covered with a green or ballast roof.Unlike other hot melt systems that use fleeces, the Paratech system incorporates a reinforcement mesh: this allows the system to be rolled out, making waterproofing installation faster, thereby enabling the contractor to lay the top roofing layer of artificial grass and landscaped green roofs. Unfortunately, an on-site compound to store the roofing components was unavailable. We worked closely with T&T Roofing and Taylor Wimpey to ensure deliveries arrived in build sequence for immediate use, but without adversely impacting residents who had already moved into their newhomes.“The features of the flat roof system provided a seamless, issue-free roof installation, with rapid installation time causing minimal disruption. Langley’s technical team was always on hand to provide assistance when necessary, working collaboratively to guarantee a consistent and highquality installation.”

Clapham ParkBauder Total Green Roof System (BTGRS) with BauderSOLAR G LIGHTSynopsisThe regeneration at Clapham Park involved the demolition of old housing stock to make way for new affordable homes. The 5-storey building with 21 dwellings incorporating the latest rooftop technology which blends a biodiverse green roof and unified solar PV array. This approach met the planning requirements and maximised the limited roof space to generate energy for the residents. The development was certified BREEAM ‘Outstanding’ due to its environmental, economic and social sustainability attributes.Bauder Building BoardProject:Clapham ParkLocation:Clapham Park, Lambeth, LondonRoof Area:500m² green roof layered with 116m² of PVSpecifier:PJMA Architects​Approved Contractor:EJ Roberts Ltd​PV Installer:M & M Electrical LtdThe specification The BauderSOLAR G LIGHT system has National House Building Control (NHBC) approval and meets local authority building control (LABC) requirements. The system was installed on zero falls roof deck, making it a very cost-effective solution.The biodiverse green roof which includes 35 plant species recognised by the RHS as Perfect for Pollinators, covers the totality of the roof area and offers a large variety of vegetation. The building reduces its carbon impact with the highly efficient PIR insulation and generates approximatively 10% of the flats usage with a maximum possible output of 75kWp from the 70 PV modules. The solar PV mounting units are ballasted by the substrate and vegetation, removing the need for any penetrating products in the waterproofing.Products appliedBauder Total Green Roof SystemThis system features a reinforced bituminous waterproofing system offering a service life expectancy in excess of 40 years.BauderSOLAR G LIGHTThe integration of a green roof and photovoltaics into one system drawing the maximum potential from a flat roof.BauderGREEN Flora Seed MixesA blend of 49 British native species seed, to maximise diversity of vegetation on green roofs.Project challengesOne of the major challenges of the project was the roof area, which at only 500m² needed to include a green roof and a renewable energy system to meet the main objectives of sustainability and energy efficiency of the development highlighted by the planning committee. The roof contributed towards requirements under National Planning Policy Framework (NPPF) Chapter 11: Conserving and enhancing the natural environment and The London Plan 2011 Policy 5.2 – Minimising Carbon Dioxide Emissions, Policy 5.3 – Sustainable Design and Construction and Policy 5.7 – Renewable Energy. The green roof is layered with a raised PV array so that the entire roof qualifies as a green roof whilst also providing energy generation.System installedBauder Total Green Roof System (BTGRS)1 BauderPLANT EA torch-applied, root resistant capping sheet. The product features chemically treated bitumen to deliver superior root resistance which has been tested and approved by the FLL. The membrane is reinforced with 250g/m² spunbond polyester fleece to allow the finished product to cope with structural movement without fracture.2 BauderTEC KSA DUOA self-adhesive bitumen underlayer with “DUO” lap technology to ensure thorough sealing of lap joints, even in lower temperatures. 3 BauderPIR FA-TEFlatboard insulation used on the lantern roof area to help meet its U-value of 0.15W/m²K. 4 BauderTEC KSD FBSA self-adhesive SBS elastomeric bitumen air & vapour control layer, with a mica finished upper surface to allow easy bonding of insulation using the specified Bauder insulation adhesive.

When Guildford Crematorium was targeted by thieves in 2011 and completely stripped of its long strip standing seam roof, the City Council considered the options for a facility that didn't have 24-hour security. Instead they opted for Rhepanol fk roofing membrane finished with its copper roof paint.

Timber frame specialist Seven Oaks Modular Ltd was awarded the contract to construct wall panels in their factory for this development, followed by delivery and installation on-site with the need to ensure the client met the target U-value of 0.19W/m²K for the wall.

These meeting spaces at the KPMG site in Edinburgh called for our advanced acoustic knowledge and for Topakustik’s design oriented manufacturing. Using the Topakustik micro perforated technology, we were able to create the image of the founders of KPMG into timber acoustic panels.

High performance timber windows and doors from the award-winning Conservation™ range by Mumford & Wood have been specified for a unique collection of 10 private new homes in a charming village close to the vibrant county town of Ipswich.

George Abbott SchoolBauder Thermofol single ply waterproofing system with Bauder Euroglaze rooflightsSynopsisLocated in Guildford, George Abbot School is a secondary education school which provides education for 2000 people aged 11 to 18. The school had a history of leaks in the DT rooms above which a profiled sheet metal roof was installed.Following many attempted repairs, Bauder was commissioned to carry out a roof survey on the 228m² profiled sheet metal roof. The report identified issues with not only the gutter area, which was originally believed to be the problematic area, but also with the adjoining profiled roof and also with the large rooflight unit.Bauder Building BoardProject: George Abbott SchoolLocation: Guildford, SurreyRoof Area: 228m²Specifier: Baily GarnerApproved Contractor: Inspire Contract ServicesThe specification Bauder submitted a proposal to refurbish all areas of the failing roof:The gutter area needing standing water to be removed for which Bauder tapered insulation was proposed to create effective drainage falls.The adjoining profiled sheet metal roof requiring a new waterproofing system. The Bauder Profiled Roof Overlay system was determined to be the best solution, using bespoke profiled insulation boards specifically designed to fit the shape of the roof. The Thermofol U15 Fleece Back membrane was then specified as the waterproofing layer providing a robust yet lightweight waterproofing system to the roof.The existing rooflight unit, being one of the problematic areas of the rooftop, was also replaced with Bauder Euroglaze rooflights. Products appliedInsulation infill systemIntended for refurbishing profiled sheet metal roofs or increasing the thermal performance of existing insulated cladding systems.Bauder Euroglaze rooflightsModular rooflight designed to provide high standards of illumination, insulation and ventilation to the interior of flat roofed buildings. These are made to order and the size can therefore be tailor made to fit any roof aperture. The resultBauder approved contractor, Inspire Contracts, installed the roof system and rooflights. Bauder’s expert site technicians carried out over 10 site visits during the 4 months of works on the site. Following a final site visit and a leak test Bauder was able to issue a 20 year product and workmanship guarantee to the client.The choice to use Bauder, a single source of manufacturing for the roof systems and the rooflight, proved beneficial as it enabled Bauder’s flat roof technician team to design out a number of the detailing issues responsible for the historic leak problems and it also eased the installation process for the client and the approved contractor, as Bauder provided its integral service from the roof survey to the final site visit and the issue of the guarantee.System installed Bauder Thermofol PVC single ply waterproofing system 1 Bauder THERMOFOL U15 FRA 1.5mm thick, reinforced PVC waterproofing membrane. Stated within BBA certificate 06/4354, the Thermofol PVC waterproofing membranes have a service life in excess of 35 years. 2 Bauder PIR MTissue-faced flat board insulation, benefitting from a zero ODP and a Green guide rating of ‘A’.3 DeckProfiled sheet metal

When regional housebuilder, Galion Ltd was looking for a way to speed up the construction process without compromising on using traditional masonry materials for its Jarmany Hill site, it turned to H+H’s Celcon Vertical Wall Panels.Celcon Vertical Wall Panels are storey-high panels of aircrete that are craned into place for a fast build with the reassuring characteristics of a high-performance, durable, masonry structure.Galion Ltd is building five large, detached houses with uninterrupted views over the Somerset countryside towards Glastonbury Tor. With a reputation for building individual properties to a high specification, the quality of the build is a strong focus for the company.Tim Barnes, Managing Director of Galion Ltd explains why H+H Vertical Wall Panels were chosen for the site: “One of the unique features of our houses is that we use local, natural stone walling for the external envelope of the properties. These are slow to build, especially when we’re using a traditional masonry build method as we are restricted to a maximum of six courses before laying the masonry to the same height.“With the traditional method it was taking 8 to 12 weeks to get to the point where we could put the roof on a house. The joy of using H+H Vertical Wall Panels is that we can get the roof on in around 8 days – it’s a huge advantage for us.”Constructing the watertight external shell of a house so quickly allows the internal trades to start work much earlier, reducing the build schedule significantly. When building large homes like the 2,800 square foot houses on the Jarmany Hill site, this time saving is particularly pertinent.Galion Ltd is working with Acorn Innovation Build Ltd whose carpenters were trained by H+H to install the Vertical Wall Panels. It was a fairly straightforward transition for them as they already use a crane to install timber floor cassettes and roof joists.Matt Shuttleworth, Director, Acorn Innovation Build commented: “H+H Celcon Vertical Wall Panels is a new system for us but as a company we are always interested in different methods of construction. I have to say, so far we are very impressed with this one.”Tim Barnes is equally impressed, saying: “I’m struggling to see a downside to the system. Everyone who has seen it has been impressed and I think once other companies see contractors building with it they’ll wonder why they’re not using it too. We’re already planning to use the system at another site that will be breaking ground soon.”

Comprising of nine shops and several residential flats, properties 29-47 High Street Polegate required a full roof refurbishment after complaints of water ingress into the residential buildings. Proteus Waterproofing conducted a thorough survey which revealed that the existing roof build up, made up of a timber deck and 2-layer felt, had been previously repaired but was now at the end of its serviceable life.Being a residential building with a combustible deck, protecting individual properties from internal fire spread was a key consideration. Compartment walls were identified allowing Proteus Waterproofing to provide a solution that would meet regulatory guidance relating to the junction of compartment walls and roofs in Approved Document B whilst meeting the needs of the client.Proteus Waterproofing specified their robust reinforced bitumen membrane range of Proteus Pro-Felt®, including a bespoke hybrid insulation approach, where instead of a full replacement consisting of entirely non-combustible insulation, a scheme was designed to meet the requirements above and either side of the compartment walls, offering the client the most cost-effective solution possible that would also mitigate any unnecessary increase of weight loading elsewhere on the roof.High Performance WaterproofingThe waterproofing and existing deck were stripped back and re- decked with 18mm plywood. When removing the existing waterproofing, our approved contractor, carefully recorded the exact location of the party walls as no drawings of the upper story flats were available.Proteus Pro-Felt® SA AVCL was used as a vapour control layer to allow for the application of the hybrid combination of 150mm Proteus Pro-Therm PIR insulation and 150mm Proteus Pro-Therm Mineral Wool insulation. A thermal calculation was undertaken to ensure that the final result met the requirements of Part L of the National Building Regulations. These were both adhered with Proteus Pro-Bond Foaming Adhesive. Proteus Pro-Felt® SA Underlay Plain was laid and finished with Proteus Pro-Felt® Ultima Plus Fireguard Mineral Capsheet, providing the client with a fully waterproofed Part B and Part L compliant roof, guaranteed for 20 years.Proteus Waterproofing worked closely with the Proteus Approved Contractor, to ensure the project was delivered to a high standard.Health & SafetyWhen working on occupied buildings, safety is always of utmost importance, as well as keeping disruptions to a minimum. The Proteus Pro-Felt® range have been tested to the highest European Classification of BROOF(t4), making it the ideal system to use on all buildings, as the risks to residents, property and members of the public are greatly reduced. All Proteus Waterproofing specifications promote fire safe installation methods conforming to the industry lead Safe2Torch guidelines. Proteus also have a range of cold liquid applied membranes which are also BROOF(t4) certified.Long Term PerformanceProteus Pro-Felt® offers high-performance bituminous membrane systems, tested to perform in extreme temperatures and weather conditions, while offering clients a robust and cost-effective waterproofing solution. Proteus Pro-Felt® Ultima Plus range retains its high polymer performance. Its class leading, high quality modified bitumen content allows this flexible membrane to move with the building and ensure long term durability and performance with third party BBA accreditation and guarantees available up to 30 years.

The project was to refurbish the roof and improve the drainage and insulation and bring it up to current building control standards. A thermographic survey of the roof was carried out by IKO, which confirmed that it was sound enough to have an overlay of IKO UXPL bituminous membrane rather than stripping it back and rebuilding. IKO UPXL was primarily chosen by the client for the 30 year guarantee. One section of the roof to be repaired was on top of dormers. Flame-free IKO UPXL membranes were used because of the potential fire risk of the abutting pitched tiled roof.

Part of the Co-op Academies Trust since 2018, Portland School in Birkenhead is a primary school for children aged 3-11. Attended by Everton and England footballing legend of the 1920s and 30s, Dixie Dean, the main school building has had many additions over time, resulting in a roof with 24 roof areas at varying levels and with various roof build-ups. The whole of this 1600 m² roof was in need of refurbishment as part of a programme of maintenance and upgrades following the school’s transition to academy status.

The Brief Our client, architect Scott Brownrigg, wanted glazed roof lights for properties within The Glasshouse, an exclusive new housing development in Putney, London to provide natural daylight and allow residents safe and easy access onto their roof terraces. The solution Surespan worked closely with Scott Brownrigg to design the roof lights to ensure they were in keeping with the style of the contemporary building. They were set to automatically open with the touch of a button so residents could easily and safely step out onto their roof terrace.

The timber finishes brings a natural warmth to the interior and exterior design. The Topakustik system will also allow the Gravetye Manor customers to dine in an area that has had the reverberation lowered, allowing great speech intelligibility whilst lowering the sound pressure levels.

ASSA ABLOY UK Specification has helped the UK’s first integrated dental hospital and school for nearly 40 years with 500 timber door sets, door furniture and architectural ironmongery for the prestigious project... Click on the link below to read more.

At The Sash Window Workshop we have been replacing and renovating timber windows and doors for various properties across London and the South for over 25 years.We were approached by an interior contracting company who were looking to replace the timber windows and doors for a property in South West London.The company requested new windows and doors which fitted the following specification:New traditional windows to match the existing style and be period appropriate;The highest possible thermal and acoustic performance;The maximum amount of light transmission possible through the glass;Bespoke window ironmongery;Painted internally to meet the customer’s specific paint colour requirements.Upon receiving the request for a quotation, one of our trained surveyors met with the architect for the project to discuss their requirements and advise how we could help. In total they required over 20 new sash windows and timber casement windows, and 4 new external wooden doors.As all of the new windows and doors that we manufacture are bespoke, we were able to ensure that their replacement windows and doors exactly matched the original designs, meaning that they fitted in with the surrounding properties and retained the aesthetic look and feel of the property.Due to the location of the property, all the new windows had to be carried up through the property by our experienced installers to be fitted.Both the customer and contractors were very happy with the work carried out, which helped transform the property into a beautiful home.

Boughton supplied IN1 Green Roof Substrate for the development of luxury roof gardens in Lillie Square, South East London.

The Ascent Aluminium Roof Access Walkway was specified to meet the clients requirement to create a level anti-slip route across the roof for maintenance personnel. The Ascent Aluminium walkway is tested for use on the aluminium standing seam roof and is secured back to the roof sheet using a proprietary support clamp. The Ascent aluminium walkway is designed in accordance with BS EN 516:2006 Prefabricated accessories for roofing, BS 4592, Industrial Type Flooring and stair treads, BS EN ISO 14122-3 Stairs, stepladders and Guardaril, BS 7976-2:2002+A1:2013 Pendulum slip resistance. And is manufactured under ISO 9001 and CE 1090 factory production control procedures, creating a walkway that is CE / UKCA compliant.

The Ascent Aluminium Roof Access Walkway was specified to meet the clients requirement to create a level anti-slip route across the roof for maintenance personnel. The Ascent Aluminium walkway is tested for use on the metal profiled roof sheet and is secured back to the roof sheet using a proprietary fixing. The Ascent aluminium walkway is designed in accordance with BS EN 516:2006 Prefabricated accessories for roofing, BS 4592, Industrial Type Flooring and stair treads, BS EN ISO 14122-3 Stairs, stepladders and Guardrail, BS 7976-2:2002+A1:2013 Pendulum slip resistance. And is manufactured under ISO 9001 and CE 1090 factory production control procedures, creating a walkway that is CE / UKCA compliant.

Also the largest public cultural space in Europe, the new 35,000m² Library of Birmingham replaces the old Central Library and is seen by Birmingham City Council as a flagship project for the redevelopment of the city.Designed by architects Mecanoo, working with multi-discipline engineers Buro Happold and main contractor Carillion, the multi-tiered roof of the library features two garden terraces which have both contributed to the BREEAM Excellent rating.Radmat Approved Contractor Prater delivered a roofing solution that is BBA Certified to last ‘the life of the building’. Consisting of Radmat PermaQuik PQ6100 Hot Melt Monolithic waterproofing membrane, root resistant Cap Sheet and ProTherm inverted roof insulation, the entire roof was electronically tested for integrity prior to the installation of aluminum powder coated cappings to the perimeter roof upstands.Once the installation of the 7,500m. of PermaQuik PQ6100 roofing system on the roof and ground level podium deck was signed off by a Radmat Technical Adviser, Prater brought in specialist green roof contractor Frost Landscapes. They then carried out the installation of the complex intensive green roofs, at levels 3 and 7, which were created to attract local wildlife and to offer visitors a pleasant environment to enjoy all year round.Combining durability and flexibility with independent verification of life expectancy and a market leading guarantee the PermaQuik PQ6100 Hot Melt Monolithic waterproofing system is set to deliver exceptional performance befitting of the uniquely designed structure which has set a remarkably high standard for library design.With Radmat’s high performance roofing solution providing weathertight protection for years to come, the Library of Birmingham looks set to not only form the catalyst for further regeneration within the city but also how future libraries are designed and perceived by the user.

The Fixfast living roof retention system has been used as part of a stunning Sky Garden green roof installation in Hertfordshire, which featured on Grand Designs. 175m of 100mm EdgeGuard aluminium retention angles surround the perimeter of the living roof, preserving its unique appearance, and maintaining the integrity of the gravel fire breaks.

Welsh Slate has supplied roofing slates from both its Penrhyn and Ffestiniog quarries to provide a like-for-like replacement for an old 19th century roof at London’s famous St Martin-in-the-Fields church complex through roofing contractors NDM Leadsheet Specialists Ltd working for main contractor Costain Ltd.