Loft Insulation Case Study — SuperFOIL Upgrade Around a Gable Window and Central Walkway, Oxford

The problem

Tom contacted us because the loft was used for routine access but became uncomfortably cold in winter. The rooms below were reasonably insulated at ceiling level, yet the roof space itself experienced large temperature changes.

The gable window provided natural light, but the exposed rafters meant the loft followed outdoor temperatures closely. Tom wanted to retain the window and walkway while improving the roof envelope.

Our assessment

The loft floor measured approximately 37m² and the pitched roof measured approximately 48m². The existing 300mm Knauf floor insulation and central walkway could remain. We recommended SF19 SuperFOIL across both roof slopes, with careful detailing around the gable window, ridge, eaves and timber cross members.

The installation

The floor insulation and walkway were inspected before temporary protection was installed. A long work light was positioned near the hatch and then moved along the walkway.

SuperFOIL sheets were installed from the lower roof slopes towards the ridge. Joints were overlapped and taped, and the material was cut neatly around the window reveal and timber frame without restricting access or daylight.

The opposite roof slope was completed in the same way. The eaves ventilation routes remained open and the walkway was cleaned before the final inspection.

The result

The loft kept its natural light, central walkway and existing floor insulation while gaining a continuous SuperFOIL roof-pitch layer. The finished space felt brighter, less draughty and more stable in temperature throughout the day.