Cast Stone - Smart Choice For Construction

Toby Marlow, Building & Construction Director from Haddonstone, outlines why cast stone is the smart choice for modern construction and historical renovation...

Natural stone, such as marble, slate and sandstone, has been a core construction material around the world for centuries; think the Taj Mahal, Palace of Westminster, the Palace of Versailles, and the Leaning Tower of Pisa, for example. Weather-resistance, beauty, durability, and low maintenance contribute to the appeal of natural stone yet today, natural stone’s drawbacks are apparent.

With sustainability at the heart of all modern building specifications and regulations, this material that requires time-consuming extraction methods, costly cutting and finishing processes, and where replenishment of stocks can be inefficient, is a great challenge.

Cast stone, first used to build a medieval fortification in Carcassone, France in 1138, is a versatile, cost-effective alternative which is also proven in some of the most iconic buildings of the world. It is a practical construction material which can be moulded into an array of intricate designs and, because each component, whether a coping, cornice or column, is created in moulds, it’s possible to create large quantities of each without compromising on quality and uniformity.

Cast stone, which can be reinforced with steel and cast with lifting sockets, boasts a consistency which is ideal for high-end developments where a cohesive, luxury aesthetic is demanded.

Key to the imaginative designer is the fact that the versatile stone can be produced in a number of coloured finishes meaning that replacing existing features when preserving or extending historic buildings is easily accommodated. The material is strong with a good freeze and thaw resistance compared to natural stone and, whether the restoration is structural or cosmetic, high specification cast stonework can help bring historical architecture back to life.

Turning to the environment and sustainability, using limestone aggregates from local quarries over heavy natural stone imported from more distant regions, lessens the environmental disruption and carbon footprint caused by the intense excavation and transportation of natural stone.  For further information, call 01604 770711 or visit  www.haddonstone.com

TDBL nonut® Follows Golden Thread For BSA Compliance

As illustrated by a recent commercial office project, cladding specialists are increasingly turning to SFS Group Fastening Technology’s innovative TDBL- nonut® fastener to ensure their installed systems achieve the objectives of the Building Safety Act, while at the same time, enabling fast and efficient installation.

Launched last year, TDBL- nonut® carries ETA-11/0191 approval, confirming that its patented thread shape, under-head locking detail and tri-lobular geometry together ensure that the fastener remains firmly in place and cannot be loosened. It represents a game-changing alternative to traditional nuts and bolts, allowing easy installation from one side of the structure: backed up by full testing and analysis.

The contract concerned a two-storey building where the architectural cladding specialist involved was seeking greater certainty over performance to discharge its obligations to the client and design team. The situation prompted its management to engage with SFS Group Fastening Technology as a trusted manufacturer serving the roofing and cladding industry.

A representative involved in the project explained: “It is essential for contractors to have a robust fastening between a curtain wall and the substrate – in this case, a steel frame system. The product selected over a traditional ‘tech screw’ was the TDBL-nonut®, which carries full ETA testing. As a result, nonut provides the robust data needed to support compliance with the Building Safety Act.”

Vincent Matthews, Head of UK Marketing for SFS comments: “The client was seeking a failsafe means of connecting their curtain wall system to the building’s structural steel frame which would offer them technical certainty, through the design process, back to the main contractor. The Building Safety Act is looking for everyone involved within a project to provide the Golden Thread: to offer a demonstration of the technical values, and how they all come together, and SFS TDBL- nonut® provides this set of data which can be used for a product and support the requirements of the Building Safety Act.

“Significantly, the TDBL- nonut® provides a tri-lobular start to the install procedure, which makes the operative’s life easier by reducing the torque load transmitted back into their hand and arm; the thread then becomes effective around the full 360^o as it connects with the components. Finally, the impact overdrives the TDBL- nonut® to ensure a reliable and secure connection that is warrantable under the ETA.”

The project team further highlighted the benefits of SFS’s support: “From the outset, SFS’s assistance proved invaluable. Their technical experts guided us through detailed calculations and product selection to ensure the right fastening solution was used. The TDBL-nonut® impressed us with its simplicity and reliability — drill, drive, tighten — making installation quick and consistent. It’s a robust, time-saving product supported by excellent technical expertise.”

TDBL- nonut® is a case hardened, thread forming fastener available in a diameter of 8.6 mm with a length of 16 mm and in a diameter of 10.6 mm - with lengths of 23, 30 and 50 mm as well as a new lower profile flatter head version of each. Further installation details and design values can be found within the assembly instructions, ETA and product literature.

For further information, call 0330 0555888 or visit https://uk.sfs.com/

Timber Treading Lightly On The Landscape - The Future For Carbon Negative Building Materials

It was back in 2012 in its Living Planet Report when the World Wildlife Fund asserted that, if the Western developed nations continued with their pattern of consumption, we would need three planet’s worth of resources by 2050. During the years since then, consumerism and population have expanded across regions like Africa and parts of Asia, with supposedly sustainable activities such as sourcing the minerals required for electrical vehicles steadily scarring once pristine landscapes.

Meanwhile, the extra 1.1 billion people added to the population over that time not only have to be fed but also accommodated which means the need to access sufficient environmentally-friendly, and ideally carbon negative, building materials has become just as important a goal as maximising the cultivation of drought resistant plants. Undoubtedly, the UK is by no means the only country where housebuilding is failing to keep up with the crisis in demand.  

MMC solutions require material advancements

The past quarter century has seen significant increases in the use of Offsite technology or Modern Methods of Construction (MMC), with engineered timber being the most popular primary material across the sector in most of Europe; with producers of competing materials also embracing sustainability goals. 

Carbon negative materials are defined as those which sequester more carbon than they emit during their life cycle with other examples including hempcrete and recycled steel, aluminium or concrete.  All of them, though particularly the trio of metals, constitute a precarious balance involving embodied energy, the depletion of natural resources and the time required for their replacement.  Significantly, however, the formation of ores and other mineral deposits are defined by geological epochs rather decades. 

As an increasingly important and costly factor, the amount of energy which goes into producing common building materials is well understood, with recycled steel requiring 74% less energy for its manufacture than the virgin product, a figure which rises to 95% for recycled aluminium which is popular for secondary structural elements like curtain walling.

Recycled steel is also now being utilised for a minor proportion of the rebar required to take the tensile forces within reinforced concrete, while recycled aggregates and waste products, like pulverised fuel ash and ground granulated blast furnace slag, are routinely specified to offset the use of energy intense cement. Ironically though, the supply of PFA and GGBS is rapidly reducing as coal-fired power plants and steel foundries are razed to the ground in the fight to counter Climate Change, making the construction industry’s quest for “ConcreteZero” ever more difficult. 

The harsh reality, then, is that the heavyside construction methodologies which shaped so much of the infrastructure which surrounds us is desperately scrabbling to reach the level of sustainability which for timber can quite literally come naturally.  This fact does not, of course, mean that timber-based building systems are automatically virtuous, and due diligence has to be employed to ensure that their specification will be good for the planet.  

As the recent COP 30 in Brazil reminded us, forests are the lungs of the Earth, a resource we squander at our peril which is why chain of custody and whole life strategies for the use of wood are crucial. Indeed, the need for constant vigilance was highlighted last year by the organisation Earthsight when it produced the video entitled “Blood stained Birch” which exposed how since the start of the war in Ukraine, more than €1 billion of Russian plywood has been wrongly given FSC- accreditation by China and sold into Europe. 

Once fully implemented, the European Union’s Deforestation Regulation (EUDR) will offer a substantial bulwark against illegal and unsustainable cropping of timber, but responsible manufacturers have already made significant strides to ensure their own operations are as well managed and transparent as possible.

With a high proportion of the company’s supplies of raw materials coming from properly-managed forests within the British Isles, and huge investment having been made in areas like production, transport and cutting waste, coupled with the use of biomass for the drying processes and a policy of only buying power from guaranteed renewable sources, the entire product range of West Fraser in the UK has now achieved Carbon Negative status.

This ensures its own customer network can be assured that the panel products they are using to produce structural insulated panels (SIPs) and other offsite systems like floor cassettes, as well as for sheathing, decking and other applications, all fully meet the spirit as well as the regulations which will expand the use of carbon negative building materials.

https://uk.westfraser.com