The recycling of used tyres as an insulation material in cavity walls in a Mediterranean climate

Abstract

This paper evaluates the potential of recycling used tyres in three different states: whole, shredded & pulverised. The study looks into the best use of the material as a form of insulation in cavity walls in Malta, with a typical Mediterranean marine (island) climate, where a greater concern for cooling has always exceeded that for heating - albeit until recently. The Maltese building industry still depends on a robust building technology, relying heavily on traditional quarried stone for load-bearing cavity walls. An energy-awareness is also maturing towards curtailing carbon emissions, even if initially dominated by cost concerns, especially in view of the ever-soaring price of crude oil on international markets. Malta has also adopted the EU Directive on energy performance in buildings, thus making energy efficiency governed by national law. In consideration of today’s large amount of tyres being used and disposed of, the purpose of this study is to investigate the possibility of utilising recycled rubber as a building material, namely as insulation in cavity walls. This could replace new insulating materials, typically having a higher embodied energy content. The study evaluates the success/failure of such passive design strategies.