There are very few green building projects that are "set it and forget it." Once the installation is complete, the building owner will be required to monitor all aspects of the project throughout its lifespan. For a green roof, upkeep is especially important to maintain plant life. During the Pre-Design phase, designers and owners should have a mutual understanding of any limitations that the owner has in regards to maintenance. There is no such thing as a maintenance-free green roof (or any roof for that matter).
The Establishment Period
Green roofs have what is called an establishment period, which is the time it takes to cultivate vegetation to a point where the roof is properly covered. The establishment period is normally over when plants cover about 80% of the area they were designed to inhabit. It normally lasts around three years on average, depending on plant selection and climate. During this time, maintenance will be more time consuming and costly, since plants typically require more water, fertilizer, and protection from weeds during the first stages of their life. This time is critical for the long-term success of a green roof. If you've installed a modular system, you'll have a greater chance of success, since they are designed to protect plants and retain water best. In many cases, maintenance during the establishment period can be done by the contractor that installed the system and therefore included in the budget for the project.
Successful green roof maintenance plans require extensive documentation. Your contractor should visit regularly to either ensure that proper maintenance is taking place or to do the maintenance themselves. When they do visit, they should document the following: the date, maintenance performed, testing performed, fertilizers or pesticides applied, weather conditions, and photographs of the roof's condition. In addition to regular documentation, your maintenance plan should have a to-do list. If you've opted to provide maintenance yourself, this checklist can often be provided to you by the designer or the contractor that installed the roof. Keep all the documentation well organized and easy to access. If vegetation is wilting or you aren't seeing the benefits promised by your contractor, you can use the documentation to help you request that something is done.
Depending on your goals established in the Pre-Design phase, you may wish to perform tests that measure your success. For example, you may wish to test the soil quality or absorption rate of the plants. If anything, you can test and document the energy you will save, or the air quality surrounding the roof. Testing will give you the data you need to make improvements or justify more projects in the future.
In addition to testing performance, you may need to test for other things that might plaque your project or cause costly damage. Although green roofs last twice as long as traditional ones, you may still fall victim to irrigation leaks, moisture infiltration, membrane damage, or drainage issues. Identifying and repairing these quickly can save you money and ensure warranties are kept. One of the biggest reasons for a green roof failing is lack of surveillance and inadequate record keeping.
It is critical to understand the expectations of maintaining a green roof, or any green building project. even renewable energy technology needs regular maintenance and testing to make sure you're getting the biggest bang for your buck. Even though it may seem like the hard work is over, it takes just a little more to make sure you reach your sustainability goals.