To make the shed in my garden (built by the previous owner) a usable space in cold weather, I decided to insulate it. The construction of it is a stud timber frame of 2x4” with a corrugated metal exterior and lined inside with OSB board. The construction has created voids in the floor, walls and roof, providing a convenient space to add insulation.
I considered using natural wool insulation, as opposed to rigid insulation board, but felt that it would difficult to secure it in place in a consistent way, as well as ensuring an air gap remains between the external cladding. I decided on using Celotex rigid insulation board and used 12 sheets of 75mm thick standard 2400 mm x 1200 mm size, and two boards of the same size at 50 mm for the back wall. In total, the insulation cost £512.74 (including VAT). To prevent draughts as much as possible, I decided to tape the gaps between the boards and shed timbers. I bought about 8 rolls of foil tape to do this.
The insulation board turned out to be easy to work with, easy to cut with a panel saw and fitting snugly in the gaps and leaving plenty of space for ventilation. I found the dust created by sawing the board irritating to my eyes and breathing so as much as possible wore eye protection and a mask (although hard to do getting hot in the small space). Working overhead on the roof was the worst part as it was difficult to avoid falling dust on my face. The whole job took three days to complete and has made a substantial difference to the stability of the temperature in the space.