Designing and building a green roof is like planning and conceiving a baby. It’s exciting, fun, and can be a little nerve-racking, but it’s nothing like actually raising the baby once its been born. Maintenance is the regular, hard work that is key to a successful green roof.
According to the Green Roof Manual, “Green roofs can be designed to be relatively low maintenance, especially after the establishment period, but with rare exceptions ignoring maintenance or giving it short shrift is inviting problems.” Homeowners should set aside a reasonable amount of their green roof project’s budget towards maintenance. However, choosing a simple design and picking plants that are proven to grow well can reduce costs and labour.
Maintenance tips
- Green roofs require the most maintenance in the first two years, so spend the extra time caring for your roof during this time. Don’t get put off by having to haul your lawnmower up to the roof every week; this time will eventually pass. Do the necessary maintenance and it will pay off since green roofs have double the life expectancy of a conventional roof.
- Hand weed as often as is needed to remove invasive, non-specified plants. A good rule of thumb, according to Green Roof Technology, is every few months in the first year, three to four times in the second year and twice a year following that. Avoid using digging tools, weed cutters or other machinery that could rip the waterproof membrane or damage the green roof system.
- Although the point of a green roof is to conserve energy and water, to help establish growth on your green roof, water it for the first year. After having done so, the plants, if chosen correctly, will grow without needing water. Since roofs are open to direct sunlight (particularly south-facing sloped roofs) they have their own microclimate. Even after planting drought-resistant plants, plants can still get stressed out from periods of intense heat and dry weather in the first year as they are getting acclimatized. Remember to perform regular moisture checks during this time.
- As with any roof, clean gutters and drains regularly and make sure they drain properly.
- Green roof installers generally provide maintenance checklists. Inspect your roof on a regular basis using one of these lists for damage such as roots that penetrate the membrane and other issues: debris that blows onto the roof, diseases, pests and overgrowth.
