Unfaced insulation is a type of fiberglass batt insulation which is normally used over existing insulation.
Foil faced rigid insulation vs unfaced.
From a green building perspective as dana dorsett correctly notes either eps or polyiso is preferable to xps.
It is important not to mix them nor use the wrong faced insulation product for each task.
Faced insulation products not only use paper they can also use aluminum foil vinyl and even aluminum paper.
Any type of rigid foam will work from a building science perspective.
As john clark correctly notes your wall must have a water resistive barrier wrb.
Faced insulation is a little but not a lot more expensive than unfaced simply because of the extra material it includes.
The upside is you save money by not having to pay to add your own vapor barrier.
When it s batts or rolls of unfaced insulation it s meant to be used to add r rating values but should be installed behind the faced insulation.
His method employs zip system sheathing for structure and air sealing 2 in.
Foil faced foam for exterior insulation and a felt paper weather resistive barrier behind a rain screen.
When to use paper faced.
Kinds of insulation that don t involve facing of any sort include spray foam blown in insulation and rigid foam boards.
It s required by code.
Faced insulation has a vapor barrier or a vapor retarder the facing that helps prevent moisture from moving from one space to another.
What is the right insulation for an attic.
Foil faced polyiso is easy to tape.
Mostly paper faced insulation is the best choice for neophytes in insulation installations.
There are many types of insulation that are unfaced such as spray foam and loose fill fiberglass.