Eco Surface Solutions

Internal Cork Wall Insulation

Thin internal wall insulation cuts heat loss by 30% in 1890s stone cottage

An 1890s solid-stone Yorkshire cottage with cold walls, condensation and mould was thermally upgraded with just 6 mm of SprayCork — independently U-value tested under ISO 9869-1:2014, delivering a 30.4% reduction in heat loss through the wall.

Thin internal wall insulation cuts heat loss by 30% in 1890s stone cottage — Halifax, West Yorkshire
Location
Halifax, West Yorkshire
Property
1890s solid-stone detached cottage
Area
Full external walls
Duration
2 days
Completed
Mar 2021

The challenge

The 300 mm solid-stone external walls had no insulation — only plasterboard dot-and-dabbed straight onto the stone. Cold dabs caused dramatic cold-bridging visible on infrared imaging, leading to mould and condensation around corners and window reveals. The small gas boiler struggled to heat the property in winter and heating bills were high.

Our solution

Two layers of CorkSol SprayCork — totalling just 5–6 mm — applied seamlessly across the internal face of the external walls and around window reveals, straight over the existing plasterboard. Finished the same day with a 2 mm gypsum plaster skim. The breathable, vapour-open system preserves the traditional wall's ability to manage moisture.

Learn about Internal Cork Wall Insulation →

Results

  • U-value improved from 1.58 to 1.10 W/m²K — a 30.4% reduction in heat loss (ISO 9869-1:2014 verified)
  • Cold bridges from plasterboard dabs visibly eliminated on post-install IR imaging
  • Internal wall surface temperature lifted — controlling condensation and mould risk
  • Thin 6 mm build-up means no room-size loss, no relocation of sockets, radiators or services

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