For large to mid scale applications, a two component mixture comes together at the tip of a gun, and forms an expanding foam that is sprayed onto concrete slabs, into wall cavities of an unfinished wall, against the interior side of sheathing, or through holes drilled in sheathing or drywall into the wall cavity of a finished wall.

Advantages

• Blocks airflow by expanding and sealing off leaks, gaps and penetrations.
• Can serve as a vapor barrier with a better permeability rating than plastic sheeting vapor barriers and consequently reduce the build up of moisture, which can cause mold growth.
• Can fill wall cavities in finished walls without tearing the walls apart (as required with batts).
• Works well in tight spaces.
• Provides acoustical insulation.
• Increases structural stability.
• Can be used in places where loose-fill cannot, such as between joists and rafters.
• Can be applied in small quantities.
• Cementitious foam is fireproof.