Roof is the original slate from 1930 on boards.
Slate roof no insulation.
If you want to insulate the sloping roof you definitely don t want to install spray foam against the back side of the slates.
I am left with from the outside inwards slates nailed onto planks about a foot wide and half inch thick nailed onto the rafters which are about 10 inches by 3 inches.
Check the depth between your trusses and the slates then install the correct thickness of kingspan in the gaps allowing for a 25mm air gap between the kingspan and the slates.
Duct work is r4 2 flex off of insulated main fixed duct.
Looking to build a curved or pitched timber structure with slate roofing.
Wet heating coil is fed from a basement boiler.
A well ventilated roof space is good this stops your timbers rotting.
The space between the rafters is a bit haphazard because of the age and shape of the roof.
Rafters have no insulation under slate.
You would first have to create a vent channel under the slates by installing 1x1 sticks at the top of each rafter bay followed by stiff material like rigid foam or plywood.
Foamglas offers complete safety and peace of mind.
Duct work sitting on the floor.
Gable windows at at each end summer open winter closed.
The cellular glass is incompressible 100 fire safe and water resistant.
I was considering spray foam but i ve done some research and it seems the underside of the slate tiles need to breathe to get rid of moisture that would otherwise accumulate in the rafters and cause rot.
Similar system on first floor in the basement.
Then you will require insulation that is safe from the elements.
There s no insulation under there currently just the rafters and wood plank sheathing.