Whether your green roof needs irrigation or not depends on the type of roof.  Irrigation is optional for brown and extensive green roofs, periodical for semi-intensive green roofs and regular for intensive green roofs.  It also depends on the location’s climate and immediate conditions (shady, full sun, windy etc) and the planting design.  Different plants require different levels of water, and for example, if your roof was in a windy location, the plants and soil would tend to dry out quicker, therefore requiring more water.

Most living roofs require maintenance, however the frequency and intensity can vary quite a bit.  Let’s take a look at the requirements for the four main green roof types:

Brown or Biodiverse roofs

Biodiverse roofs tend to require minimal maintenance.  As they are left to naturally seed (natural colonisation) and have the purpose of improving biodiversity, they reap the most benefits being left alone most of the time.  With any green roof type however, clearing gutters and debris is always recommended to maintain roof (and plant!) health.

Extensive green roof

Usually planted with hardy plants such as sedum varieties, extensive green roofs require low maintenance, simply clearing gutters of debris and clearing any leaves off the roof.  There are other optional maintenance tasks to carry out, such as hand weeding and removing any unwanted seedlings, feeding the roof with an organic phosphate and potassium feed, and keeping any stone perimeters clear of dead and live plants.  The GrufeKit is a good example of a simple extensive green roof system which requires limited maintenance.

Semi-intensive green roof

Semi-intensive green roofs require periodical maintenance, and we’d advice that you have a programme in place to ensure it is carried out.  As semi-intensive roofs tend to be designed with a greater variety of plant species, these will need tending to.  The frequency of the maintenance depends on the design of the roof, but at a minimum you’d need to schedule 3-4 visits per year.

Intensive green roof

Intensive green roofs require high maintenance, and as they are often designed for recreational use, or as a park-like garden, tend to involve a large variety of plants, including grasses, perennials, shrubs and trees.  Like a garden, they tend to require similar type and frequency of maintenance.

As the types of green roof vary so much, the costs can too.  If we’re looking at the broad spectrum of living roofs, brown/biodiverse and extensive green roofs tend to involve lower costs, and as you move towards intensive green roofs, you’re looking at a higher-cost investment.  However, it is all relative to the design and expectations.  It’s always worth discussing what could be done within your budget with a consultant.

For more information on costs, please get in touch with us and we can advise.

A green roof can weigh anywhere between 65kg to 500kg per m2, it’s all dependant on the system you choose and the design.  For example, an extensive green roof can weigh between 60-150kg/m2 whereas an intensive roof tends to range from 180-500kg/m2.  A lot of the weight is dependent on the type and depth of the substrate and the planting design (for example are you including trees?  Or is it low-level, light weight planting?), rather than the system itself.

Maintenance costs for green roofs is dependant on who is carrying out the maintenance.  If you’re planning on tending to the roof yourself (only advised if you’re experienced or your roof is a simpler brown or extensive system), you’ll need to factor in costs for any feeds, watering, and your time.

If you will be sub-contracting the maintenance of your roof, you’ll need to get costs from your chosen partner.  Feel free to email us at enquiries@ans.global and we can share some budget costs for the maintenance of your roof.

Your location and aspect of the roof isn’t such a big factor affecting your green roof choice as you might think.  Sedum is a very hardy plant that is resilient to most climates, and wildflowers come and go as they please and need no maintenance.  As long as the area where you will be installing the GrufeTiles receives some light during the day, it will be fine.  For example, we wouldn't recommend a green roof if the roof is under dense tree canopy.

The main factors that should affect your decision are the purpose of the roof, and the aesthetic you’re aiming for.

If you're wondering whether your location is suitable or not, send us a photo!  You can reach us at enquiries@ans.global.

Maintenance is usually minimal for our green roofs.  We detail how to care for your green roof in our maintenance guide here.  This involves clearing the gutters or drainage outlets, feeding the roof when necessary and weeding or strimming the wildflowers as you move into Autumn.

If you've experienced an unusually dry or cold few weeks and your green roof is suffering, we recommend lightly irrigating the roof regularly for a few weeks and feeding it with fish, blood and bone (which can be found in most garden supply stores).  Otherwise, your green roof is mostly self-sufficient and requires only one full maintenance session a year.

As you can imagine, maintenance costs vary depending on the plant design, location, access, and other factors.  However, typically the cost of maintaining a living wall is approximately 10-12% per year of the original cost of the living wall.  If you’d like to get a more accurate figure, please get in touch and we’d be happy to advise!