Spray Foam Insulation

Polyurethane foam applied as a liquid that expands and cures to form a rigid or flexible insulation layer, commonly used in roof spaces to insulate the underside of rafters. While effective at filling gaps and providing airtightness, spray foam applied directly to rafters can cause structural timber decay by trapping moisture, can make loft conversion or future re-roofing difficult, and can affect mortgage and insurance valuations.