117m² Loft Strip-Out and 300mm Refill: Case Study

Back to loft insulation removal Loft insulation strip-out and 300mm refill in a 1,260 sq ft loft

Loft size: 1,260 sq ft (117m²)
The work: Full strip-out and refill
New insulation: Knauf Loft Roll 44 to 300mm
Layers: 100mm between joists, 200mm across
Disposal: Skip on site
Price: £4,199 all-in, no VAT

The Job

The customer wanted all of the old insulation taken out of a 1,260 sq ft (117m²) loft and new insulation laid to 300mm, deeper than the 270mm usually recommended. At that size, the amount of old insulation coming out shapes how the whole job is run, so disposal was planned before anything else.

Skip or Van Runs?

Old mineral wool weighs almost nothing but takes up a lot of room, even once it is bagged. From a loft this size the choice was a skip on site or several van runs to a waste transfer station, and the time spent driving back and forth would have cost more than the skip. The quote included a skip. Because insulation is so light, weight limits never come into it and the skip can be filled right up to the line.

Getting to 300mm

We used Knauf Loft Roll 44 glass mineral wool: 100mm between the joists, then a 200mm layer cross-laid over the top. That reaches 300mm in two passes instead of three, which saves most of a day's laying on a loft this size, and the top layer runs across the joists so the timbers are covered rather than left as cold strips. At 300mm it gives a thermal resistance of about 6.8 m²K/W.

What We Did

Stripped out all of the old insulation, bagging it in the loft and carrying it out to the skip.
Cleaned the loft back to the joists.
Laid 100mm of Knauf Loft Roll 44 between the joists.
Cross-laid 200mm over the top to reach 300mm.
Fitted ventilation baffles at the eaves so the deeper insulation does not block the airflow.
Insulated and draught-sealed the loft hatch, and lagged the cold water tank.
Left the loft clean and clear.

The Price

£4,199 all-in for the strip-out, skip, materials and labour, with no VAT to add: supplying and fitting insulation in a home is zero-rated for VAT until 31 March 2027. That works out at about £36 per square metre for removal and a 300mm refill together.

Removal-only clear-outs start from £499. Our loft insulation removal cost guide has typical prices by house size.

The Result

The loft was cleared back to the joists and refilled to 300mm in a single booking, with the eaves kept ventilated, the hatch sealed and the tank lagged. If your loft needs the same, send the loft size and a couple of photos through the quote form.