If your attic has a lot of nooks and crannies your best bet may be to use loose fill insulation made of fiberglass or cellulose.
Fiberglass attic insulation vs reflective.
Air migrates from warmer spaces toward colder spaces and insulation is designed to help prevent or at least slow that migration.
The key to using reflectix properly is that you should take a little time to understand how reflective insulation works in the first place.
Reflective insulation is significantly thinner than fiberglass insulation.
Radiant barriers and reflective systems.
Both types of heat are trying to enter your home on a hot summer day.
The radiant barrier resulted in roughly 4 times more savings than the added insulation.
Remember traditional attic insulation has r value that works to slow conductive heat.
What is the right insulation for an attic.
Which is better will depend on the topography of the specific roof you re insulating.
Radiant barriers reflect radiant heat.