By: Jörg Breuning
Recently we have been receiving more and more calls regarding performance issues on extensive green roofs. Most of these roofs have been installed between 2-5 years ago by various green roof companies or supplied by different manufactures. Common complaints include dying plants, drainage system failure, growing media erosion and waterproofing leaks. Especially pre-vegetated systems (planters, trays, modules) mostly don’t meet expectations or even minimum requirements for green roofs. More often than not, green roof failures are the result of simple design or maintenance mistakes.
Many failures start within the design. A poor design leads to a snowballing effect of problems, growing and gaining velocity with every movement forward. Failures also occur during the construction phase when inexperienced installers claim a certain expertise because of a prior job, a way-back education or simply because they once watched a green roof installation.
But problems can arise even sooner. We also noticed that many initial design and construction decisions are made ‘democratically’ or as a team consensus because no one person wants to carry the full responsibility on their own shoulders. Often these decisions are wrong and unrealistic. Physics, biology and chemistry are natural laws and cannot be compromised, even if done democratically.
Engineers must work within the parameters of reality and the best course of action is to always to use common sense.
In most cases things could be so easy if people would just use their own common sense and experience instead of believing all the nonsense they find on the internet.
Our commitment is to common sense, never nonsense.