Slate Roof No Insulation

A well ventilated roof space is good this stops your timbers rotting.

Slate roof no insulation.

Duct work sitting on the floor. Rafters have no insulation under slate. Duct work is r4 2 flex off of insulated main fixed duct. 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.

There s no insulation under there currently just the rafters and wood plank sheathing. 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. Foamglas offers complete safety and peace of mind. Answered 14th jan 2013 like 2.

Looking to build a curved or pitched timber structure with slate roofing. If you want to insulate the sloping roof you definitely don t want to install spray foam against the back side of the slates. The cellular glass is incompressible 100 fire safe and water resistant. 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.

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. Wet heating coil is fed from a basement boiler. 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.