Archive for category: Building News

_{Colin Hughes, Group Manager at WMC}

Wrexham Mineral Cables (WMC), a leading UK cable manufacturer, is calling for the establishment of a new fire-resistant cable standard to improve building safety and potentially save lives.

WMC’s call to action comes as the industry reflects on the 1,700-page Grenfell Inquiry report, which sets out how ‘decades of failure’ across government and the construction sector led to Grenfell Tower becoming a site of tragic loss of life.

The report makes 58 recommendations, including the establishment of a new construction regulator responsible for developing suitable methods for testing fire resistance in materials and products used in construction.

WMC says the industry reform must include a new standard that enables architects and specifiers to identify true fire survival cables, which are proven to perform to safety standards in real-world scenarios. The company warns the current regulatory framework allows for inferior cables to be used in safety-critical applications, putting lives and property at risk.

Currently, specifiers are presented with a choice between polymeric ‘soft skin’ cables and mineral insulated copper clad (MICC) cables. Due to the existing testing regime, both cable types are classed as fire-resistant, creating a misleading impression of equivalence. However, MICC cables have consistently demonstrated superior performance and are proven to perform to measurably higher safety standards in ‘real fire’ scenarios.

Colin Hughes, Group Manager at WMC, explains:

• “Fire-resistant cables are integral to maintaining a building’s critical electrical systems during a fire. For example, emergency lighting, sprinkler systems, emergency generators, smoke dampers and shutters, and fire alarms. If these systems fail, the consequences can be catastrophic.
• “Current testing standards create an unclear picture of cable performance; they treat polymeric and MICC cables as equivalent, despite their vastly different fire-survival capabilities. It’s all too easy for manufacturers to claim that products meet a required standard, even though the test methods themselves are not representative of ‘true fire’ scenarios.

“As the Grenfell report has made clear, everyone involved in construction is responsible for keeping people safe. However, architects and specifiers must be equipped to make informed choices. We need a new standard that allows specifiers to identify true fire survival cables – and potentially help save lives.”

WMC has long advocated for stricter testing standards and better fire-resistant cable specifications. In 2023, WMC published a white paper outlining how cables directly impact building safety. The paper advocates for the introduction of a higher classification of fire survival cable, which can continue to power critical circuits in the event of a fire.

Colin Hughes adds:

“Last year, the UK Government introduced stricter building regulations in England as part of new secondary legislation to implement the Building Safety Act. Unfortunately, recent events in London, such as fires at a residential block in Dagenham and at the historic Somerset House, serve as reminders that buildings of all types remain at a high risk of fire.

“This is why we continue to call on the government and industry to take action and improve building safety with the introduction of a new standard that subjects all fire-resistant cables, regardless of size or construction, to true fire scenario tests.”

CLICK HERE TO Download WMC’s white paper:

Expecting the unexpected:

specifying safety-critical circuit cables for fire survival

_{Image: UK Hempcrete}

It really doesn’t look like much, but hempcrete is the green building material that’s got eco-savvy homeowners and architects excited by its potential to be a sustainable alternative to environmentally expensive bricks and concrete.

It is made using a carefully calibrated mixture of hemp shiv – the dried inner core of the hemp plant – mixed with lime and water.

But although hempcrete seems like a very modern building material, it has a history stretching back over 1,500 years.

Hemp plaster from the sixth century still lines the walls of the UNESCO-designated Ellora Caves in India, and hemp mortar has been discovered in ancient Merovingian bridge abutments in France – which is fitting, as France was at the forefront of the 1980s drive to modernise hempcrete and introduce it to a new generation.

Back then, wet hempcrete was cast onsite, as concrete is today, but the challenge of getting the mixture right made it a tricky product for laypeople to use. Too much of any of the three ingredients could make the material runny and weak, while not enough could cause crumbling.

Its drying time also posed problems. In fair conditions, cast hempcrete can take between four and six weeks to cure. But a cold damp winter could slow the process to at least six months, restricting its mass use across northern Europe.

Impeccable environmental credentials

Despite the challenges, hempcrete’s undeniable environmental credentials have meant it was a case of when, rather than if, it would muscle its way into the mainstream building trade.

Image: UKHempcrete

Liam Donohoe, chief operating officer at UK Hempcrete – a Derbyshire-based company designing and supplying materials to building projects using hempcrete – tells Euronews Culture that sustainability plays a part in every area of the product’s development.

“Hemp, unlike conventional crops, doesn’t require a lot of fertilisers or pesticides to protect it as it grows. The type of fibrous hemp usually used in construction is a tall plant that grows quickly and so can be cropped and planted quite close together, naturally suppressing weeds,” he says.

“I’m not saying it takes no energy to produce hempcrete, it does. But when you compare it to man-made insulation and wall infills, it has an unlimited life span and the primary ingredient is a renewable crop that costs a lot less energy and carbon to produce.”

Research and development changed everything

Experiments in France and at Belgium’s University of Leuven in the early 2000s saw researchers begin tackling the barriers preventing hempcrete from realising its full potential as a mainstream building product.

The eureka moment was the development of the hempcrete block or ‘green brick’, which took the specialist skill and guesswork out of using the material.

The lightweight fibrous block opened up a new world of possibilities for the material without diminishing any of its eco-credentials. It is free from volatile organic compounds (VOC) and indefinitely retains its acoustic, moisture absorption and thermal conductivity properties – in sharp contrast to synthetic insulation that decompresses over time to become less effective.

It is now a consistent, lightweight and reliable product that can be easily transported to sites and used by jobbing builders without extensive training.

Hempcrete versus concrete

Despite its versatility, experts are quick to dismiss comparisons between hempcrete and concrete. Concrete is a reinforced, structural building material that can support its own weight, while hempcrete is used around a frame of wood, steel or concrete. Think of it as insulation that doesn’t cost the Earth.

“When hempcrete is made into blocks, it’s strong enough to support itself, so can be used to build multi-storey buildings. There are a number of examples in the Netherlands, South Africa and France, so it’s not that you can’t build high or strong structures with it, but you need to use it around a frame,” Donohoe says.

“Researchers are working on developing a structural application for hempcrete, but that currently means usually tweaking the recipe. The sweet spot is finding something that’s very consistent, that goes onto the building site just like any other building product, without compromising too much on the carbon inputs to the recipe by using ingredients that are less sustainably produced.”

Hempcrete’s time has come

Europe is setting the pace in hempcrete use

Image: IsoHemp

The major players in the hempcrete world hail from Europe. In the Netherlands, France, Belgium, Germany and Italy, hempcrete is routinely used to retrofit old buildings and form the core of new builds.

One of the biggest producers is Belgian company Isohemp. The Fernelmont-based business has been trading since 2011 and operates in five countries.

It produces more than a million hempcrete blocks a year and claims that the projects it has worked on have saved 18,000 tonnes of C02 from the environment – that’s equivalent to the emissions produced by a patrol car circumnavigating the planet 32,000 times.

Although the UK is a few steps behind the pack, the gap is closing fast. UK Hempcrete knows of 300 to 400 houses in the UK that have been built with hempcrete and sees a bright future for the product.

“The future of hempcrete will be in prefabrication using modular methods of construction. We already have timber-framed houses largely assembled in factories, brought to the site and constructed there. There’s no reason why hempcrete houses can’t be similarly prefabricated,” Donohue says.

“In Britain, companies are building conventional family homes with hempcrete that look just like estate homes anywhere in the country, but with vastly superior eco-performance benefits.

“A focus for us is retrofitting pre-1940s housing stock. We are working with community housing cooperatives around the country who have old houses that are cold and leaky. The biggest opportunity is developing that market alongside the growing newbuild market.”

But perhaps the full potential of hemp and hempcrete has yet to be realised. BMW currently use a weight-saving hemp polymer in the door panels of its i3 electric car, while in southern Italian earthquake zones hempcrete is used as a flexible building material that can cope with Earth movement, rather than rigid, brittle concrete.

The future of hempcrete as a green building material looks assured. But with researchers working on ever more innovative ways to use it, perhaps we’ve only seen a tantalising glimpse of the difference it can make.

Source: The Phoenix Newspaper