Overview of Green Roof Systems

MRC Group’s Green Roof Systems can be used with our aluminium metal roofing systems or our flat roofing waterproofing systems, thus providing with a complete solution all backed with the ‘Guardian’ System Warranty.

Green roof systems – also referred to as eco-roofs or living roofs – are an innovative way of increasing energy efficiency and drastically decreasing costs, by either partially or completely covering a rooftop with vegetation. While green roofs offer ample rooftop protection, they can also double – or even triple the longevity of a roof proving great long-term economic benefits which far out way the initial costs.

Making use of this otherwise wasted space can protect your roof from harsh South African weather conditions and the sun’s harmful UV rays. Studies show that a green roof can contribute to a reduction of water run-off by up to 75%. All this while increasing thermal performance and reducing all indoor heating and cooling requirements. Green roofing systems are favoured for use in cities due to the substantial reduction they cause in the heat-island effect, while minimum maintenance is required.

This aesthetically pleasing rooftop garden look is popular within the “concrete jungle” environment, creating a safe haven of peace and tranquillity for all onlookers, while also maintaining an eco-system for wildlife to flourish, and promoting environmentalism in a responsible and cost effective way with minimal effort.

Key Features of Green Roof Systems

  • Dramatically improve the life expectancy of your roof system
  • Filters pollutants from the air and reduces heat loss in winter
  • Increases agricultural space and provides sound insulation
  • Low maintenance and suitable for flat or pitched roofing systems
  • Promotes environmentalism with minimal effort and creates a natural habitat for wildlife
  • Reduces the heat-island effect, energy costs and Increases thermal performance
  • Reduces water run off by 75% during rainstorms and sewer overflow
  • Improves the acoustic performance of the roof system
  • Backed with the up to 20 year ‘Guardian’ System Warranty

Applications of Green Roof Systems

Green Roof Systems have been used throughout the world for centuries providing improved shelter from the elements. In the 21st century Green Roof System usage is growing dramatically as a positive solution to managing energy and rainwater management.

MRC Group brings to the African construction market over 20 years of combined experience in installing Green Roofs on both flat & pitched roof systems.

Anyone with the need to reduce energy usage and increase thermal performance can benefit from installing a green roofing system. Green roofing is a great way to promote environmentalism responsibility with minimal costs and effort – while also creating a visually pleasing environment.

  • Domestic households, Apartment Buildings
  • Hotels, Stadiums, Shopping Centres, Airports
  • Museums, Exhibition centres, Conference halls, parking garage
  • Schools, Universities, other educational facilities
  • Science and Research facilities, Hospitals, Rehabilitation Centres

Technical Data of Green Roof Systems


Roof Protection with a Green Roof

A green roofing system offers added protection through the absorption of rain water – decreasing water run-off by up to 70%. It is planted over the waterproofing membrane which extends the life of the roof by protecting it from harmful UV rays and physical damage. Installation may also include additional layers such as a root barrier, drainage and irrigation system.

Green Roof Systems Increase thermal performance

Creates thermal resistance value simply by adding mass to a rooftop – insulating the building from extreme temperatures and minimizing heat gain. Studies have shown that even an extensive green roof of 150mm can reduce summer energy requirements by up to 70%.

Green Roof Systems significantly reduce the effect of the urban heat island

A collection of green roofs specific to a single area can decrease city temperatures during the summer months due to the increased thermal effects of a green roofing system.

Green Roofs Cleans the water and air

A green roof acts as a natural filter removing carbon dioxide and pollutants from the air and impurities and heavy metals from rainwater – lowering the rate of illness and disease.

Green Roofs improve acoustic performance

The various layers of plants and soil act as an insulated sound barrier, either absorbing, reflecting or deflecting sounds waves. A vegetated roof can decrease sound levels by 8db than that of a conventional roofing system.

Reduces stress levels with a Green Roof System

These visually pleasing rooftop gardens provide a relaxing environment, and a peaceful retreat in which to relax, enjoy the wildlife and find calm during times of stress and frustration.

Intensive Green Roof Systems

These green roofing systems have a complex support structure which includes layers such as, irrigation, drainage and root protection. These can sustain larger plants, shrubs, trees and pathways due to their complexity, requiring 36 – 68kgs per square foot of growing medium.

Extensive Green Roof Systems

These are relatively light green roofing systems weighing 7 – 23kgs per square foot of low maintenance native ground cover from the region. The benefit of an extensive green roof is purely environmental, and it does not function as an accessible rooftop garden.

Guarantees & Warranties of an Over-Roofing System

MRC Groups up to 20 year ‘Guardian’ System Warranty cuts through the myth & mystic of product guarantees and workmanship warranties issued by the construction industry.

Traditionally a product guarantee would be issued by the manufacturer and the workmanship warranty would be issued by the installer of the Green Roof System. Two separate pieces of paper, with differing length of terms and when put along side each other, never answered the question of who will pay for the materials and works such the over-roofing system fail.

‘Guardian’ System Warranty is an unrivalled new era of warranty that covers Design, Materials, Workmanship & Maintenance. The length of term for each element matches and is issued as a single source, transferrable warranty for the life of the guarantee of the Green Roof System.

MRC Group challenges the construction industry to ensure that the workmanship warranty issued by contractors matches the length of term of the supplied Green Roof system, thereby ensuring high quality installations.