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18 Mar 2019

Water runs deep at the Hill House

The images reveal the pattern of water penetration at the Hill House
Water runs deep at the Hill House
Infra-red thermographic images give an insight into how deeply moisture has penetrated the Hill House, underlining the need to act now to save the Mackintosh masterpiece.

A new survey has revealed just how severe water damage is at the Hill House, Helensburgh.

The infra-red thermographic imaging surveys were carried out with the help of Historic Environment Scotland. This technology records differences in surface temperature and that shows where moisture from decades of almost constant wet weather is retained within the building.

Damp has been a problem at the Hill House since it was built
Damp has been a problem at the Hill House since it was built.

A previous thermographic survey was carried out in 2003 and these fresh images have been combined with new 3D digital survey and microwave moisture readings. Together, these three surveys allow building conservators to pinpoint areas of damp, and further understand the declining condition of the property.

Since it was completed in 1904, years of wind and rain have caused significant issues with water ingress. In efforts to protect Mackintosh’s domestic masterpiece, the conservation charity is in the process of surrounding the building with an innovative mesh structure to protect it from the weather.

The Hill House Box will protect the building from the elements
The Hill House Box will protect the building from the elements.
“By combining the infra-red thermographic survey, the 3D scan and the microwave readings, we have a very powerful tool to aid our technical understanding of the complex problems at the Hill House.”
Richard Williams, General Manager, Glasgow & West
A man surveys the damage, using a thin cane to point out damp areas, above a window in the Hill House. The window is covered by curtains made from a light fabric featuring Mackintosh motifs.

Richard continued: ‘These surveys reinforce what we already knew about the house, which is that it is very damp and has considerable issues that need to be overcome. Due to the design of the Hill House, there are many ledges, wall heads and chimneys that have had a history of many attempts to remedy, yet this problem continues

‘We also now have additional areas of concern, such as large sections of harling that have become disengaged from the walls where damp is accumulating, and internal walls we hadn’t realised were so damp.

‘We have also been able to see the direction that the water is travelling in some of the rooms, in particular in the exhibition room, where there was already clear damage.

‘The works to create the Hill House Box are now well underway and we are grateful to the many individuals who have generously donated to help us to tackle these problems. The intention is that the structure will provide a temporary respite for the Hill House pending a long-term solution to the water ingress being found, in conjunction with our Mackintosh partners.’

The unique design and materials have contributed to the house's issues
The unique design and materials have contributed to the house’s issues.

Dr Ewan Hyslop, Head of Technical Research & Science at Historic Environment Scotland (HES), said: ‘We’re very pleased to offer our skills and expertise to support the National Trust for Scotland in this important project. The Hill House is a Mackintosh masterpiece, and this project is a great example of how we can use innovative technology to better understand the risks to historic sites such as this, and inform work to conserve and protect them.’

Work to build the Hill House Box is progressing well – the site is closed while construction’s underway. It’s all due to reopen later this spring.