Porous glass in plaster removes moisture in airtight homes

Researchers in Germany have found a way of regulating moisture in dwellings by incorporating porous glass into plaster. The simple, low cost addition could prove effective in maintaining humidity in airtight homes.

A team at the Fraunhofer Institute for Silicate Research ISC in Würzburg has been developing supplements for paint and plaster that can have a compensating effect on humidity. With Building Regulations stipulating that dwellings should be airtight to save energy, moisture from cooking and showering can easily build up, which is the main cause of mildew or mould.

The researchers have selected artificially-manufactured porous glass as an ideal additive because the inorganic material’s pore size, volume and particle form can be selectively controlled – something that naturally-occurring alternatives don’t offer. Glass particles in flake form have the ability to very quickly absorb, store, and then slowly release moisture. “Walls and ceilings offer large surfaces that could be used for moisture management – and by adding glass particles to plaster, stucco and paint, we can even out daily and seasonal humidity differences,” said Ferdinand Somorowksy, researcher at the Institute. “The result is a more comfortable living space. Up to now, between 95-98% of all available plasters have been without additives.”

Researchers demonstrated that the glass flake and plaster mixture can absorb considerably more moisture than alternatives such as zeolite or fibreboard, and then release it all again. “In a room with a volume of 30m3, the walls and ceiling offer approximately 40m2 of surface area that could be used for a moisture-regulating plaster. To reduce the humidity from 72 % to 47%, some 180 ml of water needs to be absorbed. And our glass flake plaster can actually absorb more than a half litre of water,” said Somorowsky. Mould spore inhibitive substances can be added to the plaster as well.

This article, including the image, has been adapted from an article published by Technology4Change.