Green Roof Systems

Blackdown Extensive

Blackdown Extensive green roofs are designed with shallow growing media to keep system depth and saturated weight to a minimum. They typically incorporate resilient, drought-tolerant species, resulting in a system that requires minimal ongoing maintenance. 

These roofs are often selected for the environmental benefits they provide, such as creating visual impact, supporting biodiversity, managing rainwater by slowing run-off, and contributing to improved building thermal performance. Extensive green roofs are not designed for regular foot traffic. 

The range includes drainage layers, substrates, planting, and ancillary components.

  • Lightweight system
  • Improves local biodiversity
  • Suitable for low pitch roofs
  • Improves air and water quality

Green roofs require early stage decisions about access, maintenance, and intended use to ensure the design meets project expectations. Alumasc works closely with designers and specifiers from the outset to ensure every aspect of the brief is achieved. 

Extensive green roofs rely on hardy, drought-tolerant sedum species that form the majority of the planting. Planting can be supplied as a pre-grown NatureMat® (providing approximately 95% coverage at installation), a pre-grown tray system (typically providing mature vegetation coverage at installation), or plug plants (providing around 5-10% coverage at installation).  

To support these planting types, a Blackdown Extensive substrate is required. The substrate is composed of carefully selected organic and inorganic materials, blended in precise proportions to enable rapid plant establishment and long-term performance.

  • Blackdown Extensive green roofs are compliant with the Green Roof Organisation (GRO) best practice standards.
  • Blackdown green roof components comply with FLL guidelines.

Warranties are available for the Alumasc waterproofing system used in the green roof build-up.

CAD Details

System Summaries

  • Extensive Sedum Pregrown Blanket WarmDownload
  • Extensive Sedum Pregrown Blanket InvertedDownload
  • Extensive Sedum Plug Plant WarmDownload
  • Extensive Sedum Plug Plant InvertedDownload
  • Extensive Wildflower Pregrown Blanket WarmDownload
  • Extensive Wildflower Pregrown Blanket InvertedDownload
  • Extensive Wildflower Plug Plant & Seed WarmDownload
  • Extensive Wildflower Plug Plant & Seed InvertedDownload
  • Extensive Lightweight WarmDownload

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