Green Roofs

 

"Living Roofs can deliver benefits throughout the city for
individuals and for society as a whole, by creating new
outdoor spaces and enhancing biodiversity. They can
also help us adapt to the challenge of climate change by
reducing flood risk (through absorbing heavy rainfall)
and providing cooling"

Mayor of London's website

 

 

Green roof systems provide many benefits, but with their exposed position and their shallow root zone, it is vital that they are irrigated.

Access have been supplying green roof solutions for over 20 years, and have considerable expertise in the design and supply of green roof watering systems. Access can provide advice to architects and contractors on the design and installation of systems, and produce a free downloadable 'Guide to Green Roof Irrigation'.

Extensive Green Roof Irrigation

Extensive green roofs have surged in popularity over recent years, and although the plants selected for green roofs are typically drought tolerant, some form of irrigation is still necessary. Without irrigation, the carefully selected biodiversity of the original planting will give way to a mono culture as the hardiest species will take over. Occasional feeding is normally also recommended, which can easily be performed using the irrigation system.

For extensive roofs, high quality commercial grade drip line is normally laid beneath the sedum or meadow grass mats, and connected to the water supply via a break tank to comply with the water regulations. Control can either be performed manually or using an automatic controller.

Intensive Green Roof Irrigation

Roof areas often provide an untapped resource, allowing a green space to be provided for the benefit of residents or workers. The benefits in terms of quality of life and biodiversity a clear, but any plants growing on a roof deck need a regular supply of water and nutrients.

Access Irrigation are able to provide watering solutions for lawn areas, hedges, planted borders and even trees on the roof deck.

Lawn watering

Lawn areas are normally watered using pop-up sprinklers, but with the very shallow soil depth available, this can often be difficult. Low rise pop-up sprinklers can be used for smaller areas, or for more extensive lawn areas either the underlying insulation layer can be 'dipped out' at the appropriate points to give more soil depth, or the sprinklers can be fitted in raised borders around the periphery of the lawn. An alternative solution is to water the lawn using specialist sub-surface drip lines.

Border watering

Borders and planters on a green roof deck are normally watered in the same way as their ground level counterparts, with drip lines used on the planters and beds and individual drippers to smaller planters and pots.

Control systems

Precise control is vitally important on green roof irrigation systems. Not only does account need to be taken of the aspect, with South facing areas requiring more water than North facing, but if sprinklers are used, the control system needs to take account of how exposed the area is. Irrigation controllers can be linked to wind speed sensors to ensure that irrigation does not take place during high winds.

Green roof guide

For more information on green roof irrigation, download a copy of our free PDF guide 'Access Irrigation Guide to Green Roof Irrigation'.

To download the guide, just complete the quick online registration process, then log in to the download area using your email address and password.