How long does foam spray last?

How long foam spray lasts depends on type and application, but generally spray foam insulation lasts very long, often lifetime of building, 20 to 80 years or more without significant degradation if properly installed and protected from UV light. Closed cell spray foam can last 30 to 50 years or longer, maintaining R-value and structural integrity, while open cell spray foam can last 20 to 30 years but may be more prone to moisture issues if not protected. Canned spray foam like Great Stuff used for sealing gaps lasts many years once cured, typically 10 to 20 years or more in protected interior locations, but will degrade if exposed to sunlight. Foam spray shelf life in can is typically 12 to 24 months unopened, after which propellant may fail. Once applied and cured, foam spray does not expire quickly but can degrade with UV exposure, physical damage, or moisture. Properly installed spray foam insulation in walls and attics is considered permanent insulation that does not need replacement under normal conditions.