Slate Roof No Insulation

Rafters have no insulation under slate.

Slate roof no insulation.

Looking to build a curved or pitched timber structure with slate roofing. It had no insulation whatsoever between the plaster and the outside roof. Roof is the original slate from 1930 on boards. 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.

Duct work is r4 2 flex off of insulated main fixed duct. The cellular glass is incompressible 100 fire safe and water resistant. 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. Answered 14th jan 2013 like 2.

Then you will require insulation that is safe from the elements. A well ventilated roof space is good this stops your timbers rotting. Foamglas offers complete safety and peace of mind. Wet heating coil is fed from a basement boiler.

Roofing felt was introduced primarily to act as a secondary barrier against wind driven snow and rain but its use also causes a reduction in air movement within the roof space particularly if the roofing felt is impervious and this effect is often compounded by the introduction of insulation. The space between the rafters is a bit haphazard because of the age and shape of the roof. Gable windows at at each end summer open winter closed. Duct work sitting on the floor.

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.