This article has been written to clarify the many different terms associated with green roofs.
A Biodiverse roof is designed to support many different wildlife species on the roof.
The existence of a wide variety of plant and animal species in their natural environments, which is the aim of conservationists concerned about the indiscriminate destruction of rain forests and other habitats
Brown roofs are designed to support many different species of wildlife on the roof.
BBA accreditation is an accreditation linked to waterproof membranes
A change in global or regional climate patterns, in particular a change apparent from the mid to late 20th century onwards and attributed largely to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels
Drainage Layers/ boards
Drainage layers are usually part of the standard green roof systems. The boards or rolls come in different sizes for different green roof types. The drainage layer helps excess water leave the roof comfortably.
DIN Standards are German Ratings given to products that meet the requirements. DIN’s are placed on waterproof membranes.
Ecological or Environmental
Extensive Green Roof
Extensive green roofs are a low nutrient, low maintenance green roofing solution. These types are generally lightweight.
Filter fleeces are a non-woven geo-textile that holds the fines within the system, but allow water to pass through. This layer goes underneath the substrate (growing medium) and stops the substrate draining out of the system.
The FLL guidelines are the European parameters for green roofs
A green roof is simply vegetation intentionally grown on a roof.
Green Roof System
The Green Roof system is the build-up of layers that create the green roof.
Growing Medium / Substrate
Growing medium is a scientifically engineered soil replacement designed to support the vegetation layer. The growing medium is designed to be free draining and also aerate the system.
The Green Roof Organisation. This is an industry based forum that is dedicated to high standards and the development of green roof materials.
Hydro-seeding is a blend of cuttings, seeds and growing medium that is sprayed onto the roof.
Intensive Green Roof
An intensive roof is usually a ‘roof garden’ it requires a continual maintenance and irrigation.
Plug plants are small saplings planted on the roof. Usually planted at 20 pr meter square.
A Reservoir board holds some water in cups as storage for when the plants need it.
A root barrier is a layer that goes on top of the waterproof layer it stops any roots damaging the waterproof membrane.
Sedum is a type of planting used in green roofs. It is the most common type at present.
Semi-intensive Green Roof
Semi-intensive green roofs supports shrubs and lawns it is in between an extensive green roof and an intensive green roof.
Substrate/ Growing Medium
Substrate is a scientifically engineered soil replacement designed to support the vegetation layer. The growing medium is designed to be free draining and also aerate the system.
Sustainable Urban Drainage systems – A sustainable urban drainage system is designed to reduce the potential impact of new and existing developments with respect to surface water drainage discharges.
Waterproof membranes make the roof watertight before the green roof system is installed.