A green roof is a living roof system where plants grow on top of a waterproof membrane, providing natural insulation and stormwater management. The lifespan of a green roof depends heavily on the quality of the waterproofing layer beneath it, the type of plants used, and the maintenance it receives. Typically, the waterproof membrane beneath a green roof lasts around 20 to 30 years, similar to traditional roofing materials. The plants themselves can thrive for many years if properly cared for, but they require regular watering, weeding, and occasional replanting. Without maintenance, plants can die off, and roots can cause damage to the membrane, shortening the roof’s life. Green roofs are also exposed to the same weather extremes as traditional roofs, including sun, wind, and rain, which can affect both the vegetation and the underlying structure.
To check the health of a green roof yourself, start by inspecting the plants for signs of sickness such as yellowing leaves or bare patches, which might suggest issues with drainage or soil. Also, look for pooling water or leaks inside the building, which could indicate damage to the waterproof layer. It’s important to avoid walking on the plants excessively to prevent injury to the roof system. If you notice cracks in the membranes during visible inspections or persistent leaks indoors, it’s time to call a professional roofer familiar with green roof systems. When meeting a contractor, ask “What type of waterproof membrane do you use, and what is its expected lifespan under a green roof?” and “How do you recommend maintaining the vegetation to avoid damage to the roof structure?” These questions help ensure your green roof will remain healthy and protected for years to come.