Expanding foam is a type of insulation material that comes in a can and expands when sprayed. It is commonly made from polyurethane and is used to fill gaps, cracks, and cavities in buildings. This foam hardens quickly, creating an airtight seal that helps improve energy efficiency and reduce noise. In addition to insulation, expanding foam is also used in construction and DIY projects. It can be applied around windows, doors, and pipes to prevent drafts and moisture infiltration. Its versatility makes it a popular choice for both professional contractors and homeowners looking to enhance their spaces.