Green Roofs and Rooftop Gardens

A green roof, also known as climate roof or rooftop garden, is the roof or deck onto which vegetation is intentionally grown or habitats for wildlife are established. Green roofs contribute to restoring vegetation in the urban environment and could mitigate increased urban temperatures. Green roofs can therefore make a significant contribution and present practical solution in the quest for sustainability, increased biodiversity and quality of life.  

Why Go Green? Benefits of Choosing a Green Roof

Green roofs offer specific benefits for end users, residents, owners and the general public. These range from economic and environmental to social and aesthetic reasons. Just to name a few:

  • Protecting and prolonging the life of the waterproofing membrane
  • Reducing heat-island effect in cities
  • Improve thermal performance of the building
  • Slows down storm water flow by retaining up to 75% of rainwater, thus alleviating the pressure on storm water and drainage infrastructure
  • A natural environment on the roof with natural CO2 absorption

Green Roof Systems

There are essentially two types of green roofs, extensive green roofs and intensive green roofs. Both have their own advantages. Depending on the requirements of your project and your individual needs, one or the other is more suitable.

If you would like to know more details about how green roofs work , you can do that here.

Extensive green roofs are lightweight and require less plant maintenance. With only a few centimetres of soil, extensive green roofs typically support plants that drought-tolerant such as grasses and windflowers since they are shallow-rooted and use little water. Extensive roofs are often used in areas that will not be subject to regular traffic.

Sika buildup illustration rendering showing extensive green roof layers

Intensive green roofs are heavier, and hense require far more maintenance. They are designed to include a deeper soil that can accommodate trees, shrubs, bushes and vegetable gardens.  

Sika buildup illustration rendering showing intensive green roof layers

Why Choose a Sika Green Roof?

Green Roofs with Sarnafil and Sikaplan PVC Single Ply Membrane Systems

Sika has proven a track record of over 30 years with green roof construction. All of the Sarnafil and Sikaplan single ply roofing membranes used in these systems are:

  • Resistant against biological and micro-organisms
  • Fully resistant to root penetration
  • Sarnafil and Sikaplan can be installed in most weather conditions, even in minus temperatures. This gives a unique flexibility to contractors, their clients and designers
  • Soil with a minimum weight of 80 kg/m2 provides the necessary wind uplift resistance, eliminating the need for any additional mechanical fastening
  • Sika’s experts provide assistance in your project milestones if needed, including design assistance to architects and specifiers and authorised applicator training

Green Roofs with Sikalastic Liquid Applied Membrane System

The two component spray applied Sikalastic® are also ideally suited to green roof systems:

  • These systems have full surface adhesion to the substrate, eliminating the risk of lateral water flow under the waterproofing system, so that any potential leaks from future damage can't spread along the roof surface and therefore they can easily be identified and re-sealed
  • Fast machine application and curing with 2-component PU material
  • All Sika's liquid membranes used in green roof construction have excellent root and micro-organism resistance
  • The products can be applied directly on to prepared concrete decks and so they are ideal for inverted roof build-ups
  • Sika’s experts provide assistance in your project milestones if needed, including design assistance to architects and specifiers and authorized applicator training


Green Roofs with SikaBit Bituminous Membrane System

SikaShield® P55 PE RT 4 mm is made up of distilled bitumen modified by  elastoplastomeric polymers in order to increase the durability and the resistance to high and low temperatures.

  • Torch applied waterproofing membrane with an anti root additive specially designed to protecting roof gardens, sunken works and gravel covered roofs
  • Resistant to chemical effects of humid acids and fertilizers, allowing the membrane to be in direct contact with the soil or where there is risk of the system being attacked by roots