Aerogel plaster is sprayed onto walls of historic buildings. (Credit: Empa)
Renovating any historic structure is a project that comes with numerous challenges, one of which is how to insulate the interior without altering the appearance of the exterior. One group says that aerogel may be the key to solving this dilemma.
Researchers at the Swiss Federal Laboratories for Materials Science and Technology claims to have developed a high performance plaster using an aerogel. The material is said to insulate three times better than conventional insulating render, containing perlite or expanded polystyrene.
According to an Empa press release, the mineral basis of the material likens it to original historical building material, both visually and in application. It can be sprayed both on internal and external surfaces. The aerogel plaster is water repellent and permeable to water vapor. It can be used with conventional plastering machines.
“The porous structure of the aerogel makes the plaster permeable to water molecules, but for macroscopic water droplets the nano-pores are much too fine,” developer Thomas Stahl says.
The cost is expected to be between $50 and $100 per square meter above conventional materials, depending on how thickly it is sprayed on. The material will undergo field trials over the next year, and should be commercially available by 2013.
No information was provided about the composition of the aerogel or how the plaster is prepared without disturbing the aerogel’s brittle structure.
UPDATE: Thomas Stahl returned our requests for additional information about the material. He says the key component is silica aerogel. When asked how he combats the brittleness factor and handling problems normally associated with aerogels, Stahl claims this is not a problem because silica aerogel while in the plaster is extremely stable at hydrostatic pressure.
Stahl also notes that no special equipment is required to use the special plaster and that all of their tests were conducted using “common plaster machines.”
Additionally, here is a photo of silica aerogel in its “raw” state.