A new Aerogel-based plaster has been developed that provides twice the insulation of the currently used insulating renders used to insulate old buildings. The product is expected to come onto the market next year.
In Switzerland, there are currently one and a half million old buildings, yet these old buildings are difficult to insulate and expensive to heat. The country’s energy consumption is increasing, according to the Federal Office of Energy. 4.5 million tonnes of light fuel oil and 3 million cubic metres of natural gas are imported every year, 43 percent of which is used for heating.
Cutting down on the heating necessary for old uninsulated buildings would go a long way towards reducing total fossil fuel use. But how do you insulate old historical buildings without ruining them?
‘Rendering’ is the most desirable way to maintain the look of an old house while increasing the insulation. The alternative, cutting and installing custom-shaped boards to line the winding staircases, round arches, and supporting walls of historic building isn’t cost-effective.
“An inner lining of insulating render is considerably quicker to apply,” says Empa building physicist Thomas Stahl. “The render also lies directly on the brickwork and does not leave gaps where moisture could condense.”
“Stahl and his colleague Severin Hartmeier from Fixit’s central laboratory made it their task to take the insulating properties of render to a new level, and to develop a render that provides as much insulation as a polystyrene board.”
And now, after years of research, their work has finally paid off: “The product has come through laboratory testing, and initial trials on buildings started in July 2012. If the new insulating render holds up to its promise, the material could come onto the market in the course of next year.”
The render devised was a new aerogel-based plaster, somewhat modified from previously used versions. Aerogel, also known as “frozen smoke” because of the way it looks, is composed of around 5 percent silica and 95% air. “Aerogel was used back in the 1960s for insulating space suits, and has 15 entries in the Guinness Book of Records, including ‘best insulator’ and ‘lightest solid.'”