The Gannochy Trust Cottages
Thermal Improvements to Interwar Period Properties
The Gannochy Trust was founded in 1937 by Arthur Kinmond Bell, known as A K Bell, for charitable and public purposes as a direct result of his family’s successful distilling business. A K Bell’s first project built the Gannochy Housing Estate between 1925 and 1932 to provide rented accommodation for the people of Perth.
The Trust contacted us to assist with their programme of thermal improvements, and we have now successfully insulated the exterior perimeter walls with Icynene to a number of their properties as part of a rolling programme of works incorporating a number of thermal upgrades.
The measures installed were part of the suite of thermal interventions for traditional and historic buildings developed by Historic Scotland. The success of this project was recognised by The Green Organisation with a Green Apple Award in summer 2015.
The scope of works varied from house to house; mostly the walls only were treated, with some underfloor insulation sprayed to the underside of the floorboards (whilst maintaining airflow across the solum) if space allowed…the minimum requirement being a clear 5009mm below the underside of the joists.
If the underfloor is left unsealed, it is necessary to seal the perimeter area with material in order to contain the injected foam. In some cases it was necessary to remove some skirting boards and extract debris which otherwise might cause cold bridging, although in most properties these areas were found to be clear after borescope inspection.
As part of the upgrade project the Trust replaced all the kitchens, giving the ideal opportunity to gain access to the walls behind to ensure complete coverage. Where removal of kitchen units is not practical the material is injected through the backs of cupboards and drawers after appliances are removed.
Where it was decided to remove or replace shelving units in the press cupboards, the material was sprayed directly to the stud framing and trimmed ready for the installation of plasterboard.
The Sprayfoam injection process helps to ensure that any lath and plaster does not blow out, however special care is to be taken around weakened areas which have been repaired with plasterboard, or where dwangs or noggins have been placed and may restrict the expansion of the material.
The fully open-cell structure of Icynene ensures that the introduction of insulation does not affect the hygrothermal properties of the wall construction, allowing bi-directional breathability whilst eliminating the convective heat losses.
Kishorn Insulations have successfully insulated many properties of this type in Scotland, and continue to offer cost effective, bespoke solutions for historic and listed properties where other systems may be deemed inappropriate or impractical.
You can download the full Historic Scotland report below...