Typical Green Roof Assembly
Six Layer Diagram
A green roof system begins above the roof membrane. Since roofing systems vary on individual assembly, we have provided detail of assemblies dependent on the roof membrane system. Not all membranes are resistant to root penetration; some are designed to shed water while drying and some are soluble over time with constant contact with water. Select a roofing system suitable for a green roof.
The six layers of a typical roof assembly from plant palette to the roof membrane are:
- Plant Palette: Plants that are suitable for growing in available media depth
- Growing Media: A lightweight media designed for green roof systems
- System Filter: A separation fabric that allows over 120 gpm of flow during storm events
- Drainage Layer: The part of the system that channels excess water away from the roof system
- Protection Material: A fabric layer that protects the membrane
- Root Barrier: An impermeable barrier to root growth
- Roof Membrane
Not all assemblies will require components 5 or 6–it will depend on your membrane type.
Assembly
The attached system assemblies are drawn over suitable green roofing membranes. The details illustrate how to assemble a “built-up” green roof system and the best practices in dealing with roofing penetrations, terminations, and roof drains. The drawings are to assist you in the understanding of the Extensive green roof assembly only.
Each drawing will contain an Extensive system design over a generic roofing membrane type. The depth of the example green roof system is not to suggest a profile requirement. Media depth is determined by roof weight load capacity and plant root system requirements.
Please access drawings by clicking here and you will be able to register/login to download.
Please contact us if you have any questions, or need additional assistance planning for an Extensive, Semi-Intensive or Intensive Roof System.