This is foxes shute garage roof conversion. All work is in line with planning. The old roof was concrete fiber sheets. The original timber was rotten as was the wall plate so we had to replace them. We then insulated inside and out. 
We battened over the insulation and the felted the roof. This was then crossed battened. Due to the low pitch off the roof we had to use specialist slates which interlocked so that when the wind hit them they would not lift and break. The Chimney stack was built up through the roof  to the specification of planning.