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Extensive Green Roof System

Features and benefits:

  • Designed for extensive green roofs with a 100–150mm overall depth.
  • The vegetation can be grass, sedum blankets, sedum or wildflower mixes, or herbs.
  • Each layer of component is supplied separately in bag or roll form and installed separately as a “dry” build-up, allowing easy access to roof areas.
  • Suitable for large scale areas, unlevel or more complicated decks as it is flexible and “built into” the existing structure.

General information
Uniclass 2015
Ss_45_40_47_28 Extensive green roof systemsPrimary

Q37/130 Extensive green roof

Specification data - Extensive green roof systems
Product Reference

Extensive Green Roof System

Protection board

Not required


Geotextile filter fleece

Recycled polyester

300 g/m².

Drainage layer

Protecto-drain 20P

Growing medium -

Insert requirement, available 100–150 mm.


Not required



Plug planted extensive roof

Sedum blanket

Sedum/ wildflower mix

Standard product features

Drainage layer:

  • Protecto-drain 20P perforated drainage sheet.
  • Thickness: 20 mm.
  • Can be cut and shaped around particular details.

Geotextile filter fleece:

  • Weight: 100–1200 g/m² (generally 300 g/m² required for component green roof systems).
  • See clause 360 for product descriptions.
  • Laid above and below drainage layer.

Growing medium:

  • Crushed lecca / crushed brick / crushed concrete.
  • Green waste (up to 30%).
  • Locally sourced marine aggregate and grit.
  • Peat (10%).
  • Moisture retention polymer.
  • 12–14 month release fertilizer, if required.


- Plug planted extensive roof:

  • Requires 150 mm (maximum) substrate.
  • Plug planted vegetation installed on site.
  • Large variety of foliage available.
  • Very low lead times.
  • Can be installed at any time of year.
  • Can take up to 24 months to be fully established.
  • Less rainwater runoff (60% (maximum) retained).
  • Requires higher maintenance.
  • Saturated weight: Up to 150 kg/m², depending on vegetation.

- Sedum blanket:

  • Requires minimum 70 mm substrate.
  • Supplied in nine month old, established blanket, to give instant green roof.
  • Very low maintenance; weed clearance required once per year.
  • Drought resistant; little irrigation required.
  • Approximate saturated weight: 80 kg/m².

- Sedum/ wildflower blanket:

  • Requires minimum 70 mm substrate.
  • Plug planted mixture and established into thin layer of substrate.
  • Native, local plants can be used, including herbs, bulbs and heather.
  • Can take up to 24 months to be fully established.
  • Fairly low maintenance depending on vegetation.
  • Approximate saturated weight: 80 kg/m².

Maximum roof slope:


Product Options

Protection board:

  • Polymeric Protecto-Board.
  • Thickness: 3 mm.

Third party certifications
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