The Business Today The only manufacturer of lime-based building products in Wales; The largest UK outlet for many of our insulation, paint and hydraulic lime products; Employ between people in a very rural part of Wales.
Lime – an ecological material?
How is lime produced? Calcium Carbonate CaCO 2 Quicklime Calcium Oxide CaO Slaked Lime Calcium Hydroxide Ca(OH) 2 Burnt in a Kiln at 900oC Carbon Dioxide Given Off Add to Water Carbonation Takes Place Carbon Dioxide Reabsorbed Water Given Off
Foresight Project Scientists at Bristol University have calculated that overall using blue lias hydraulic lime instead of cement for building has an energy saving of around 40%.
Lime Mortar vs Cement “…cement production is responsible for 1500 million tonnes of carbon dioxide each year (that’s 10% of worldwide CO2 production), the environmental argument for lime in new build is also a compelling one”. IJP, Countryside Building
Properties of Lime-based Materials they are porous and absorb moisture from the surrounding bricks or stones. Any salt or frost damage occurs in the lime, thus protecting the surrounding materials;
Properties Continued they allow walls to ‘breathe’ - moisture will evaporate as rapidly as it enters (unlike in most modern mortars and paints which hold moisture in the wall) thus helping to control damp and condensation.
Properties Continued they are relatively flexible and will accommodate some movement in a wall. If they crack, they will ‘self-heal’ when exposed to air;
Properties Continued they allow materials to be re- used – much of todays cement building and pointing is tomorrows land-fill.
Properties Continued they enable low energy sustainable materials such as straw, woodfibre board, reeds, coppiced timber to be used as construction materials as it breathes and keeps them dry.
The Idea Using crushed, recycled container glass instead of sand in our lime mortars and plasters.
Why Glass? Concern over the extraction of sand (around 200 million tonnes per annum in the UK); Glass makes up 8-10% of average household waste; 2 Million Tonnes of glass is used as packaging in the UK, in 2000, 25% of it was recycled in the UK, 3.5% in Wales - compared to Switzerland’s 95% and 55% as a European average.
Why Performance Assessment? Traditional Lime Mortars and Plasters made with sand have a proven track record of 2000 years or more, however, we noted a reluctance to using a glass substitute as it has no track record and the Construction Industry increasingly require product testing/certification for a product to be widely acceptable/useable. Another concern was the potential contamination of glass (as we were unable to secure a ‘washed’ aggregate source in Wales), e.g. from bottle-tops (aluminium metal) carbohydrates from contents of bottles etc.
Progressing Assessment However, when we looked at the technical implications and costs of undergoing the necessary tests (and the potential for escalating costs if the work programme had to be amended during testing), we decided not to proceed down that route! However, over a period of about 3 years, we had trialed the products at Ty-Mawr and were very encouraged by the results…we therefore started looking at testing and potentially certification again – as well as sources of financial assistance.
How we went about getting help? We met with the Wales Environment Trust who put us in touch with WRAP and the Welsh LEADER Plus Programme (GLASU) – we felt we were able to contribute to the objectives of both, and hence we were able to secure financial assistance; The Wales Environment Trust then helped us to source glass and complete application forms.
Progress Having secured financial assistance, we were then able to agree a programme of work and tests with the BRE in June 2003 Submitted a proposed Quality Plan in August 2003 Submitted samples to the BRE and testing commenced in November 2003 Results are due during the first 2 weeks of June - we hope that they reflect the findings of our own trials over the last 3 years.
Future Get results of a feasibility study to establish a ‘local’ crushing plant to meet the BRE requirements on June 9 th Test results and Feasibility Study permitting: –we would immediately start to encourage the specification of glass instead of sand in lime mortars and plasters starting with a formal launch of the product in Wales on the 18 th June –we can then begin manufacturing (already have the mechanisms and capacity). –consider full certification.