Old tyres used in new roof studies

Russian scientists are using old tyres to cover roofs by grinding them into powder and mixing with common polyethylene.

"Initially the aim of the study was to solve the environmental problem of tyre recycling," said Olga Serenko from the Institute of Synthetic Polymeric Materials in Moscow. "We found the obtained composite is better than some common covering materials."

But the new application for old tyres is unlikely to reach the UK in the near future.

The Building Research Establishment (BRE) told CJ it is not undertaking any research into this area. "We are completing a project where old bitumen felt is recycled into roads and pavements. I was under the impression that polyethylene is a bit dodgy with regards to exposure to UV radiation," said Gerry Saunders, BRE's roofing expert.

"There is a new breed of polyolefin-based membranes (including polyethylene), but these are engineered from new materials. They are considered to be a replacement for PVC," he added.

"I would be very wary of rubber membranes. The first generation in the UK literally fell apart at the seams due to low bond strength. I am also reminded of a product manufactured many years ago that was full of various polymers and performed fantastically well in the lab, but 18 months on site saw it start to shrink. Also the new generation of polyolefins are proving more difficult to install because welding the seams needs more control," explained Saunders. "But it could be worth a trial."

Serenko pointed out that the rubber-LDPE composite has been perfected by adding a small portion of ethylene and vinyl acetate copolymer to improve the binding between rubber particles and the polymer. "Varying the quantity of polymer creates harder composites which can be used to manufacture roof slates," he said.