phenolic foam

Phenolic foam is a synthetic polymer insulating material which is inserted or layered into wall or roof cavities as an air-propelled spray. It can contribute to air sealing and acoustic insulation, and it can be inserted into spaces where other forms of insulation (such as fiberglass or cellulose) are present.

The definition concerns foam inserted or sprayed in place. Rigid phenolic insulation boards have a separate panel form.

The foam can occupy cavities alongside other insulation materials. Some phenolic foams shrink after curing, which can affect contact with the surrounding surfaces.