Brains plus balls

After spending 20-odd years plastering walls, all Glenn Melvin wanted was to get off the tools. But instead of helping him realise his vocational ambition as site manager, the HND course he took in building launched him on a quest to invent the world's most thermally efficient plaster.

And he did it! According to BRE tests, a 50mm external coat of his plaster can cut a household's energy consumption by 24%. Designed for solid-wall structures, the plaster achieves the same 0.055w/mK value as fibre insulating board at half the cost.

It was his HND's environmental sciences module that got Melvin interested in creating an energy-saving plaster. He was drawn to expanded polystyrene (EPS) because it's such a good insulator. But working out how to deliver it as a bona fide plaster took two years of experimentation. Melvin spent his evenings and weekends in his garage, with bags and bags of EPS, every render known to man and a huge array of gypsums, sands, additives and aggregates.

Mixing them together, he plastered the result on his garage's four walls, hacking it off several days later as each successive mix failed to make the grade.

New balls please
Why didn't he just give up and sit his site manager's exams? "There had to be some reason it wasn't working," Melvin says. Success came when he asked an EPS supplier to manufacture polystyrene in the smallest possible size it could manage. The tiny balls, combined with super-fine aggregates and a range of additives, produced a workable plaster that didn't crack or crumble.

Since then, he's put the plaster, called WallReform, through official testing regimes. There's a BBA certificate to say it does what it says on the bag, and BRE has calculated the energy savings. And having made sure he recorded every scoopful of material he ever used, Melvin can reproduce the mix exactly – as can the manufacturer set to make the product in commercial quantities.

He's even got a showcase project. Last summer social landlord Tyndale Housing tried out WallReform as a cost-effective way of upgrading five cold and damp prefabricated concrete bungalows in Hexham, Northumberland, without the disruption to tenants caused by internal insulation.

Melvin decided to take along his trowel and do the job himself. He had to fix lengths of EPS before painting a stabiliser onto the walls, plastering on 50mm of WallReform and finishing off with a yellow acrylic coat that matched the paint job.

The job was good enough for Tynedale, which intends to use WallReform again. Dave Tiffin, Tyndale's clerk of works, says the tenants will be monitoring their fuel bills to see how effective the insulation is. "I've already had comments from tenants about how much warmer their place is. They're like little igloos now." Rather alarmingly for the tenants he adds: "I hope we get a cold winter to see just how good they are."