SCIENTISTS have developed new techniques that could protect historic buildings like York Minster from erosion.
The latest findings from Karen Wilson, formerly of the University of York, may reduce the impact of atmospheric pollution that causes stone to decay.
If her technique is found to be successful in the long term, her research could help better protect against natural weathering.
The limestone walls of the Minster have undergone periodic restoration over the years, though some of this is thought to have accelerated erosion.
Previous techniques that attempted to reduce the rate of decay involved coating walls in a special hydrophobic – or water-repellent – layer.
The formula, however, stifled the walls and prevented the natural expulsion of salt from within the limestone, creating a salt build-up which is damaging for limestone.
To combat this, the new technique developed by Ms Wilson combines fatty acids and chemical compounds in order to generate hydrophobic and super-hydrophobic surface coatings.
These coats allow the Minster walls to “breathe” – keeping the atmospheric pollution out and allowing salt to be expelled naturally.
Ms Wilson was a senior lecturer at the University of York before moving to Cardiff University, where she was appointed a readership in physical chemistry.
She said: “It’s long-term work. The next step is carrying out field studies by testing the Minster walls on site over the next few years.
“We’ve got the proof of our principle, our work with the Minster wall samples was a great success, now we just wait and see.”
The research, which has been funded by the EPSRC/AHRC Science and Heritage Programme, could also be used to promote the conservation of other historic buildings which are made from limestone.