There are also no battens!! This is because the slates are so wide they span the 12″ rafters and are nailed with two nails into each rafter. As some of the slates are so wide, they are nailed into three rafters.
When stripping slates to patch, the underside is caked in the chinese clay which was produced locally and shipped out in the bay.
So we’ve applied the system to the roof, saved the client the cost of re-slating (the building and harour is grade II listed), issued our guarantee and saved another fabulous old roof.