A vent baffle should be installed between the insulation and the roof decking to maintain the ventilation channel.
Insulation under the roof.
The insulation boards are best fitted under the roof structure whilst the mineral wool can be inserted between the beams of the roof.
The quest for greater energy efficiency in buildings has led to increasing interest and need for insulation improvements in hvac equipment more airtight construction new materials and assemblies.
The material is compressible and is thus easy to fit and is less likely to cause cracks.
Arguably the most popular pitched roof solution installing insulation between and under the rafters uses the depth of the structural timbers to best effect.
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.
Water is insulation s enemy.
An efficient room in a roof in a new build property where over rafter insulation is not desirable.
Look for water stains on the roof sheathing or damp or moldy spots on attic joists and existing insulation as a clue to where leaks might be.
You can also add rigid foam insulation under the rafters which adds r value and eliminates thermal bridging through wood rafters.
Its versatility is the key to its popularity whether being used to achieve.