Pre-grown, low maintenance biodiverse green roofs

Watch our How to Install video.

Component green roofs consist of a drainage layer, filter layer, substrate and sedum blankets or plugs, all installed separately.  Once installed the green roofs need irrigation and regular maintenance to aid establishment for 6-9 months after installation, requiring access and a permanent water supply to the roof.  In contrast, extensive sedum or brown modular roofs are pre-grown for 12-16 months prior to installation, and therefore do not require intensive aftercare or irrigation once installed.  This mitigates the risk of failure.  Modular systems are typically easier to install in most applications.

We recommend these few tools to help you install your GrufeKit (some are only necessary if you need to cut the modules to fit):

• Hacksaw
• Pliers
• Handsaw
• Tape measure
• Scissors
• Gloves
• Utility knife

Extensive: the simplest family of green roofs, these are covered with low growing plants such as evergreen sedums.  From a distance an extensive sedum roof can be mistaken for a grass field.  Besides the visual impact of an extensive green roof, they also provide a natural habitat for birds and insects.

The main difference with a ANS GrufeKit extensive roof is that it comes in kit-form and is quick and easy to install, not to mention the fact that it is pre-grown and therefore green from the start and does not require irrigation.

Semi-intensive: a slightly more diverse green roof with more soil, allowing for small shrubs as well as the low-growing sedums and wildflowers found on extensive roofs.  A semi-intensive roof can give rise to a richer ecology; however, this depends on the purpose (for human use or biodiversity).

Intensive: usually a deeper substrate depth which allows for taller growing species such a shrubs or trees.  These typically require intensive maintenance and irrigation and are used recreationally which reduces their biodiversity value.  It’s hard to believe that you are on a roof with some of the designs for intensive green roofs!

There are a number of reasons to consider including stone areas on a green roof, including factors like the roof's exposure to wind, the regulations you are following in the area where you are installing, and whether the aesthetics were a reason behind the installation of you or your client's green roof. 

 Let's go into more detail:

 Access: as plants such as Sedum are not intended to support frequent foot traffic it would be a good idea to consider stone paths if frequent access is required for maintenance or leisure

Aesthetic: some roof designs use stone areas to create artistic patterns or even a simple border might add character in some situations

Fire break: the FLL Guidelines and the GRO Green Roof Code include requirements for the provision of fire breaks within green roof design

Wind resistance: in particularly blustery areas a stone border can be used to prevent the chance of wind uplift pressures on the green roof

Prevent debris: a stone border can effectively stop wind-borne plant parts and debris reaching the edge of the roof and gutters

Meet regulations: some councils stipulate the inclusion of stone areas for a number of reasons (usually to act as a fire-break)

So while not all green roofs require stone areas it is often a wise consideration based on the reasoning above. If you are looking to include stone in your green roof we have some quality Scottish pebbles for this purpose, and for roofs needing a stone border where there is no parapet or upstand, you might consider using a GrufeGuard too.