Box out light fixtures.
Insulation between roof trusses.
It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow.
A vent baffle should be installed between the insulation and the roof decking to maintain the ventilation channel.
Water is insulation s enemy.
Consider using high density r 30 batts which are as thick as r 25 batts but fit into 2x10 framing.
With a regular roof insulation isn t a problem.
Improving your home s energy efficiency rating.
Insulation between the joists keeps warmth in your living space below and creates a cold loft while insulation in the rafters allows you to keep warmth in the roof space as well.
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.
When it comes to pitched roofs however adding a thick layer of insulation to the rafters can result in a depth of roof construction that may not.
Convenience polyurethane or polystyrene spray foams can provide thorough coverage to roof rafters and attic walls in much less time than is needed for other materials.
To insulate the underside of the ceiling between rafters you ll want to add insulation to the exterior portion of the finished ceiling.
Increasing your home s value.
Uneven or sloppy application however can make the insulation ineffective and unsealed open cell insulation can absorb moisture causing the roof to rot or leak.
You can also add rigid foam insulation under the rafters which adds r value and eliminates thermal bridging through wood rafters.