SWD250 Spray Rigid Polyurethane Foam was developed by SWD Urethane Co. USA in the 1970s. It has been widely applied for building wall heat insulation in the US and be certified as Energy Star by the USEPA. SWD250 polyurethane foam is a dense structural microporous foam material with low absorption rate, good permeability resistance, above 95% of closed cell content. Applied with direct spray technology, no seams among foam layers that a complete impermeable layer is formed on the substrate. It creates a protection layer avoiding water absorption and perfectly resolves the building walls water-leaking problems and heat insulation issues.