The reflectix site provides a great range of information about this and about how it differs from other types of insulation.
Fiberglass attic insulation vs reflective.
Find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces.
In a new house an installer typically drapes a rolled foil radiant barrier foil face down between the roof rafters to.
The sun heats up the roof and then the heat is transferred by radiant heat across the attic space until it hits the attic insulation.
Which is better will depend on the topography of the specific roof you re insulating.
Both types of heat are trying to enter your home on a hot summer day.
Fiberglass has been in use by builders since the later portions of the 1800 s.
Air migrates from warmer spaces toward colder spaces and insulation is designed to help prevent or at least slow that migration.
The reflective insulation trade association also offers installation tips.
Reflective insulation is significantly thinner than fiberglass insulation.
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.
Radiant barriers reflect radiant heat.
Fiberglas insulation has been the undisputed standard for buildings for many years but foil insulation is the new contender.
Remember traditional attic insulation has r value that works to slow conductive heat.
Next i compared adding an additional r 19 to my existing r 19 level of attic insulation vs installing radiant barrier and the results actually surprised me a little.
Fiberglass insulation comes in larger batted rolls but is also found as a blow insulation that is primarily used in attics.
The key to using reflectix properly is that you should take a little time to understand how reflective insulation works in the first place.
It s easier to incorporate radiant barriers into a new home but you can also install them in an existing home especially if it has an open attic.
What is the right insulation for an attic.