This activity is about application of aerosol applied 1-part fire resisting foams for firestopping of linear joint seals. This includes checking information relating to application, adopting safe, healthy and environmentally responsible working practices, using materials, components, tools & equipment, and preparing and applying suitable products. The activity could be carried out during building construction, or during repenetration of compartments during installation of additional services or maintenance activities. Polyurethane (PU) based foam gap fillers are usually supplied in an aerosol can with a dispenser to guide and shape the resulting mix. The foam sets at room temperature to provide a seal that can fit around difficult to access constructions.