Foil Faced Rigid Insulation Vs Unfaced

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 rigid insulation vs unfaced.

As john clark correctly notes your wall must have a water resistive barrier wrb. Foil faced polyiso is easy to tape. Mostly paper faced insulation is the best choice for neophytes in insulation installations. It is important not to mix them nor use the wrong faced insulation product for each task.

When to use paper faced. 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. Kinds of insulation that don t involve facing of any sort include spray foam blown in insulation and rigid foam boards.

Air migrates from warmer spaces toward colder spaces and insulation is designed to help prevent or at least slow that migration. 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. It s required by code. Any type of rigid foam will work from a building science perspective.

What is the right insulation for an attic. There are many types of insulation that are unfaced such as spray foam and loose fill fiberglass. Faced insulation is a little but not a lot more expensive than unfaced simply because of the extra material it includes. Choosing the right thickness of exterior foam rigid foam must be thick enough to prevent condensation on the roof sheathing.

Foil faced foam for exterior insulation and a felt paper weather resistive barrier behind a rain screen. 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.