Insulation Slate Roof

The materials used to insulate under the roof include batts of mineral or glass wool insulation held in place by battens of wood attached to and across the rafters alternatively polystyrene.

Insulation slate roof.

A well ventilated roof space is good this stops your timbers rotting. If you create an air space under the roof sheathing boards as dana suggests there is no need to have any soffit vents or ridge vent. The underside of the roof sheathing will dry rapidly to the exterior through the slate due to ventilation drying and diffusion. It is vapor permeable and air leaky.

Where the felt is impervious any contact condensation will run down the felt and make the insulation damp. Ice water shield. Answered 14th jan 2013 like 2. Insulation is often laid in contact with the roofing felt.

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. Insulation laid so that it covers the eaves significantly reduces ventilation to the roof. If you want to insulate the sloping roof you definitely don t want to install spray foam against the back side of the slates. 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.

Read about how to install starter courses take a look at common contractor errors watch some video clips read about drip edges and cant strips if necessary look at some of the nuances that may be pertinent to your installation such as cleats on aprons cleats on.