What is Spray Foam Insulation?
Spray foam insulation is a liquid plastic made of polyurethane and isocyanate that is sprayed into place, where it expands and hardens to create a continuous insulating and air-sealing barrier. It can be used in walls, roofs, and other surfaces to resist heat transfer, reduce air infiltration, and create an air and moisture barrier.
Open Cell or Closed Cell?
There are two main types: open-cell, which is less dense and often used for soundproofing, and closed-cell, which is denser and provides a higher R-value per inch and a vapor barrier.
Types of spray foam insulation
Open-cell foam:
Characteristics: Less expensive, lower R-value per inch, permeable to moisture, and good for soundproofing.
Best for: Situations where soundproofing is the priority and moisture is not a concern, such as for interior walls or in warmer climates.
Closed-cell foam:
Characteristics: Higher R-value per inch, a more rigid structure, and creates a vapor and air barrier.
Best for: Colder climates or areas where a vapor barrier is needed, such as in exterior walls or in attics to keep heat inside.
Benefits & Considerations
Benefits: Improves energy efficiency, provides an air and moisture barrier, and can be applied to complex or hard-to-reach areas.
Considerations: Can be more expensive than other types of insulation, and improperly installed foam in a roof assembly can trap moisture, potentially leading to rot.
