Divine insulation – ADC

Castlehead Church, an imposing, 18th century, stone-built structure in Paisley, south west Scotland had lain empty since its closure in 2010. Historic records linked the church to both Robert Tannahill, a popular poet from Paisley and contemporary of Scotland’s National Poet Robert Burns, and former US President, Ronald Regan who, with his wife Nancy, visited the building in 1991 to view the grave of his great-great grandparents who are buried there.

Glasgow-based property developer, Cleveden Homes recognised the potential of the now empty building and in 2017, submitted plans to convert the site into luxury apartments. “The basic shell of the building was still in good shape despite being well over 200 years old,” says Alex McGurk of Cleveden Homes. “It’s a rectangular plan structure with rubble walls and ashlar dressings. The fenestration is impressive with an imposing door to the main gable, flanked by tall windows, as well as five tall windows to both of the side walls.”

Cold and draughty

In common with most buildings constructed centuries ago, the builders thought little of how to prevent heat loss through the walls and roof. McGurk continues, “Churches throughout the country have a reputation for being cold and draughty, and Castlehead was no different. Our top priorities were making the structure as airtight as possible, and ensuring high levels of thermal insulation”

Cleveden Homes brought in insulation specialists JSJ Foam Insulation of Eaglesham, Glasgow, for guidance. Jim Shearer of JSJ recommended insulating the entire inner surfaces of the building with H2Foam Lite, a breathable spray foam insulation system from Huntsman Building Solutions (HBS).

HBS H2Foam Lite, open-cell insulation

H2Foam Lite is a high-performance spray-applied foam insulation, originally developed in Canada to cope with severe winter conditions, and now manufactured at Huntsman’s facilities in Kings Lynn. According to Jim Shearer, the system is now widely used in Scotland and the rest of the UK in both commercial and residential buildings.

H2Foam Lite is a flexible ‘open cell’ material with an elastic, yielding texture. It provides outstanding levels of thermal insulation yet allows the building to breath naturally, resisting internal condensation and at the same time eliminating air leakage – more commonly known as draughts. “Up to 40 per cent of a building’s heat loss can be attributed to air leakage,” says Shearer, “so it’s vital that reducing air leakage is included in any programme of measures to improve a building’s thermal performance.”

H2Foam Lite is installed using a pressurised gun system. Foams are applied as a two-component mixture that come together and expand 100-fold within seconds, closing off all gaps, service holes and hard to get to spaces that conventional insulation materials may fail to reach.

Low environmental impact

Unlike the polyurethane foams of 20 years ago, modern spray foams, such as H2Foam Lite, use water as the blowing agent. This means that the reaction between the two components produces a small amount of CO2 which causes the foam to expand. foam cells burst and the CO2 is replaced by air. From an environmental perspective, H2 Foam Lite has a Global Warming Potential (GWP) of 1 and an Ozone Depletion Potential of 0 (Zero).

Insulation was applied to the inside of all the external walls as well as the roof structure. The walls were sprayed to a thickness of 165mm between timber studwork and to a thickness of 320mm within the pitched roof. Studwork dividing walls were also insulated to provide high levels of thermal and acoustic insulation.

Spray foam converts

Cleveden Homes has created a development of seven luxury one, two and three-bedroom apartments over four floors with ground floor parking and lift access to floors above. There is approximately 1000-square-metres of floor area in total.

Commenting on the use of spray foam insulation, Alex McGurk said, “Speed of installation and minimal waste were key factors in our decision to use spray foam. That, and the overall lower cost of spray foam, because we didn’t need to commit trades to the time-consuming process of cutting and fitting rigid board type insulation really clinched it. We are spray-foam converts!”

Cleveden Homes is progressing well with the Castlehead Church repurposing project and anticipate completion in Winter 2022. Thanks go to Cleveden Homes and JSJ Foam Insulation in the preparation of this article.

Contact Details

For more information, please visit the Huntsman Building Solutions website.