Foil Faced Rigid Insulation Vs Unfaced

There are many types of insulation that are unfaced such as spray foam and loose fill fiberglass.

Foil faced rigid insulation vs unfaced.

Faced insulation is a little but not a lot more expensive than unfaced simply because of the extra material it includes. Unfaced insulation is a type of fiberglass batt insulation which is normally used over existing insulation. Faced insulation products not only use paper they can also use aluminum foil vinyl and even aluminum paper. As john clark correctly notes your wall must have a water resistive barrier wrb.

Unlike faced insulation unfaced insulation lacks a vapor barrier or retarder meaning it does not provide moisture control but it s more economical than its faced counterpart. The upside is you save money by not having to pay to add your own vapor barrier. It is important not to mix them nor use the wrong faced insulation product for each task. Air migrates from warmer spaces toward colder spaces and insulation is designed to help prevent or at least slow that migration.

Any type of rigid foam will work from a building science perspective. Mostly paper faced insulation is the best choice for neophytes in insulation installations. 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. Choosing the right thickness of exterior foam rigid foam must be thick enough to prevent condensation on the roof sheathing.

His method employs zip system sheathing for structure and air sealing 2 in. Kinds of insulation that don t involve facing of any sort include spray foam blown in insulation and rigid foam boards. When to use paper faced. Faced insulation has a vapor barrier or a vapor retarder the facing that helps prevent moisture from moving from one space to another.

Foil faced foam for exterior insulation and a felt paper weather resistive barrier behind a rain screen. It s required by code.