Loft Insulation Case Study — Combined Loft Upgrade Around a Central Chimney Breast, Birmingham

The problem

Hannah contacted us because the bedrooms beneath the loft were difficult to keep warm during colder evenings. The heating brought the rooms up to temperature, but the warmth disappeared quickly once the system switched off.

The loft survey showed that the floor insulation varied in depth and had been disturbed around the chimney and hatch. The roof pitch had no insulation at all, so the loft itself became extremely cold in winter and very warm during sunny periods.

Our assessment

The loft floor measured approximately 41m² and the pitched roof area measured approximately 57m². We recommended topping the floor insulation up to a consistent 300mm using Knauf glass mineral wool, fitting SF19 SuperFOIL across the roof pitch and extending the raised boarded area to 12m². The chimney breast, hatch frame, eaves and structural timbers all required individual detailing.

The installation

Loose debris and compressed insulation were removed before the existing material was redistributed. A 100mm layer was fitted between the ceiling joists where required, followed by a 200mm cross-laid layer to create a consistent 300mm floor build-up.

SF19 SuperFOIL was then installed across both roof slopes. The material was fixed across the rafters, cut neatly around the chimney breast and roof timbers, and overlapped and taped to form a continuous layer. Ventilation paths were preserved at the eaves.

A 12m² raised boarding platform was completed around the hatch, leaving a stable route through the loft without compressing the new mineral wool.

The result

The completed loft had full-depth insulation at ceiling level, a continuous reflective layer across the roof pitch and a practical boarded area around the hatch. The upstairs rooms retained warmth for longer, while the loft felt less affected by rapid outdoor temperature changes.