Cob Blog

Tradical® Hemcrete®, the innovative lime and hemp based renewable and highly thermally efficient alternative to conventional masonry cavity walls, has achieved British Board of Agrément (BBA) accreditation. With approval from the UK’s major authority on construction products, specifiers of Tradical® Hemcrete® can have total confidence in the product’s performance.

Developed in Europe by Lhoist and manufactured and distributed in the UK by Lime Technology, Tradical® Hemcrete® is produced from UK sourced hemp and a lime based binder (Tradical® HB). The product is carbon negative, as the hemp absorbs CO2 during its growth – and as such has 130kg less embodied CO2/m² than conventional brick and block in a normal wall section.

Alongside its environmentally beneficial production, Tradical® Hemcrete® offers superb insulation properties. The low U-value of walls built with the renewable system make it an ideal material for meeting the higher levels of the Code for Sustainable Homes.

Homes built with Tradical® Hemcrete®, also have excellent thermal inertia, meaning that they buffer temperature variations efficiently. This ensures heating or cooling needs are lower than in lighter weight buildings of the same U-value.

Highly vapour permeable and used in conjunction with lime based renders and plasters, it ensures a healthy internal environment. Tradical® Hemcrete® also has high fire resistance, making it a safe choice for any construction.

The accreditation comes as part of Lime Technology’s commitment to provide designers with the ability to specify a lime based, BBA approved, building solution for the construction industry that they can have complete confidence in.

“With BBA accreditation, our clients are now fully assured that Tradical® Hemcrete® has been rigorously and independently assessed for its performance as a walling system for use in all building types,” said Mike Eberlin, Managing Director of Lime Technology. He added, “It’s another step towards ensuring Tradical® Hemcrete® is seen as a commercially viable material for the mainstream construction market.”

The developer of Tradical® Hemcrete®, Lhoist, is the world’s leading industrial lime manufacturer. First formulated in France, Lhoist brought the technology to the UK in conjunction with Lime Technology with a view to providing this sustainable technology to the mainstream construction market. BBA accreditation was seen as an essential part of the process and Lhoist UK has worked with Lime Technology to provide the required assessment information to BBA that has resulted in the successful awarding of the Agrément Certificate.

BBA accreditation is highly trusted by construction professionals as providing a rigorous, independent assessment of construction materials and systems. This initial certification is the first of its kind awarded to a hemp lime construction system anywhere in the world.

Francois Bardout, Vice President & General Manager Lhoist UK, commented. “We are delighted by the award of this BBA accreditation because this paves the way for this highly sustainable construction system to be adopted more readily by designers and clients as part of their environmental strategy to help tackle climate change.”

The presentation of the BBA certificate was made at Ecobuild, the world’s largest eco-construction exhibition event, on 2nd March 2010, by Greg Cooper the Chief Executive of BBA. Where I also spent three days. On my feet. The whole time. Owch!!!

An article in the New Scientist (26th Feb 2010) asks how much further can we push the planetary life support systems that keep us safe?? Apparently more than you’d think.

The demands of the nearly 7 billion humans on the planet are stretching the Earth to breaking point. The obvious threats are climate change and pollution but what effect do other environmental influences have, such as acidifying oceans, mass extinctions, dead zones in the sea, etc. A team of researchers from Sweden identified 9 ‘life support systems’ that are vital for our survival.

Acid Oceans – The oceans have absorbed 75 – 80% of the CO2 that they can before it is expected that widespread death and dissolution of corals. This might not sound that important until you consider that they are at the bottom of the food chain and therefore support a massive proportion of sea life. It is expected that we will reach 100% by the middle of next century.

Ozone depletion – The hole in the ozone layer that formed in the 1970′s was a classic example of an environmental tipping point. Ozone depleteing chemicals built up in the upper atmosphere until suddenly they caused a large hole to appear in the ozone layer. Fortunately most of these chemicals are now banned and the hole has all but healed. Diagnosis – safe and improving!!

Fresh water use and Land use for agriculture are another two areas that were looked at and showed that although we hadn’t reached the estimated limits we are fast approaching them. Agriculture is exacerbating climate change by destroying ecosystems and damaging the fresh water cycle. The over use of water is causing huge changes in wetlands and destroying fisheries and in some areas causing them to become more arid. One of the main users of fresh water are cotton and biofuels.

The other boundaries are Biodiversity loss, Nitrogen and phosphorous cycles (the amount of nitrogen and phosphorous being put into the earth), Climate Change (amount of warming gases entering the atmosphere), Aerosol Loading (the amount of aerosols being put into the atmosphere) and Chemical Pollution.

When you look at these areas you see that we have exceeded one third of them (climate change, biodiversity and nitrogen fixation), we are on the boundaries of another third (fresh water and land use and ocean acidification) and two of the final three we do not understand what the limit could be. On the positive side we have brought the ozone layer back from the brink and it is still getting better.

We can make a difference to the other eight areas but we must strongly and urgently take action.