Roof Garden Maintenance

Posted on June 8, 2017 in Gardening

The maintenance of green roofs is perceived to be one of the greatest barriers to their installation.

The maintenance schedule should be considered during the design process, when the demand for maintenance input can be anticipated.

There is no such thing as a ‘no’ maintenance roof, green or otherwise. All new commercial buildings are required to have roof and gutter checks twice a year and an extensive green roof can be designed to align with this requirement.

The maintenance required will depend on the outcome desired by the client; this may range from weekly checks during summer on an intensive roof garden, to quarterly or even twice yearly checks on the most extensive green roofs. However, it is strongly advised to include the cost of the post installation maintenance programme within the budget and tender documents.

Biodiverse roofs and those designed to be low-maintenance will still require visits once or twice a year to clear gutters and drains and remove any unwanted debris or litter. Extensive sedum roofs may require a more intensive maintenance regime, with some manufacturers recommending weeding three times a year and application of fertiliser once a year. Semi intensive roofs (unless a biodiverse type) and intensive green roofs designed with aesthetic appeal or the functionality of a roof garden, will necessarily dictate a more intensive maintenance regime, as would be required in most gardens.

Maintenance usually occurs in late winter or early spring. Where breeding birds are expected such works should be undertaken before the nesting season begins. Roofs near to deciduous trees also need maintaining in late autumn to clear leaves.
Many contractors will include, or at least suggest and offer, an agreed period of regular maintenance. This is especially important whilst the roof is establishing. Some extensive green roof system suppliers will have their own approved contractors who will monitor progress immediately following installation and after the first full growing season (usually between 12-18 months) before finally signing over maintenance duties to the building manager.

There are an increasing number of maintenance contractors who have received specialist training in green roof care from organisations such as GRO (The Green Roof Organisation) and BALI (British Association of Landscape Industries).