Extensive Green Roof System

This is the substrate/growing medium in which plants grow. These specially formulated growing soils promote healthy sedum growth and minimise weeding. For extensive green roof systems these typically range from between 80mm to 150mm in thickness, depending on planting method and local environmental site conditions.

A Moy Filtration Fleece is a geotextile fleece layer which is laid over the drainage and reservoir board. This allows excellent vertical drainage capacity, whilst also filtering sediments and fine particles out of water flowing into the drainage layer.

The Moy Drainage & Reservoir Board Drainage & Reservoir layer is a drainage and water storing board. These layers come in a range of depths and provide excellent water storage, water flow capacity and a very high compressive strength.

Prior to the installation of the Green Roofing System, a Moy Protection & Water Storage Fleece must be installed to ensure adequate protection of the waterproofing layer.

Moy waterproofing system is installed as appropriate. Extensive Green Roofs can be installed over most warm roof systems, including Paralon Reinforced Bitumen membrane, FiberTite® Single Ply and Enkopur Liquid Waterproofing. They are also suitable for use over Inverted roofs.

Thermal insulation is an essential component within a warm roof system. Its purpose is to control and maintain the temperature of the building below. It’s important to ensure a sufficient thickness of insulation is installed in order to meet the requirements of the appropriate Building Regulations and local legislation. Other considerations are critical when selecting the type of material used as a thermal insulant due to the additional weight of a green roof, are the compressive strength and loading capacity of the insulation. Acoustic properties, fire performance and compatibility with the waterproofing system should also be checked.

The purpose of the air and vapour control layer is to reduce or control the passage of air and moisture vapour passing from within the building, up through the roofing system, potentially causing risk of interstitial condensation within layers of the roof construction or allowing increased levels of air leakage.

Where applicable, depending on the type of AVCL used, an appropriate primer may be necessary over the roof deck, prior to the application of the AVCL.

The structural roof deck spans the structural frame of the building to provide a continuous support for the roofing system and ultimately what the roof is attached to. This may be in the form of a profiled steel, profiled aluminium, concrete or timber deck. It is critical the deck is designed to accommodate the additional design loadings expected of this roof type.