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Extensive Substrate in Bulk Bags

A free draining, low nutrient and moisture retentive growing medium made from 100% recycled material in line with

Supplied in 1m3 Bulk Bag

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(Excl. VAT £22.60)

Depth (mm)
Required Bulk Bag: 2

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Bulk Bag
Of CO2 Offset by
your roof per year

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Total: £113
SKU: SBS01BB Categories: ,
  • A specially blended mix of free draining organic material with clean and screened aggregates. Recycled from certifiable waste products in the building industry to provide a low nutrient water retentive growing medium.All testing of Sky Garden Ltd Substrate was completed by Sports Turf Research Institute under the BS8616:2019 Specification for Performance Parameters and Test Methods for Green Roof Substrates. A free draining substrate suitable for use on Extensive Roof Systems and all plant finishes.

    • Minimum recommended depth: 50 mm
    • Free draining when saturated
    • Allows root penetration
    • Recycled content
    • Organic material PAS100 certified.

    Features and benefits


    Recycled Materials


    UK Green Roof Code of Best Practise


    Organic Material

    Low Nutrient

    BS8616 standards by STRI Groups.

    Moisture retentive

    Growing Medium

  • Technical Properties Substrate Depth Recommend depth 80 – 150mm
    Technical Properties Compaction 15%
    Technical Properties Bulk Density when oven dried 0.80 g cm 3 (800 kg/m3
    Technical Properties Bulk Density at field capacity 1.10 g cm 3 (1100 kg/m3
    Technical Properties Calculated Bulk Density at Saturation 1.36 g cm 3 (1360 kg/m3
    Technical Properties Total porosity (%) 55.80%
    Technical Properties pH 7.8
    Technical Properties Electrical Conductivity (mS cm 1 2.22 mS cm 1
    Technical Properties phosphate (mgl 1 127 mgl 1
    Technical Properties Potassium (mg l 1 435 mgl 1
    Technical Properties Total nitrogen (%) 0.04%
  • All your materials arrive in one delivery from our UK farm and are simple to unload and install straight away.


  • Popular FAQs

    • Do I need planning permission?
      Most green roofs can be installed with no planning permission, however some do require it. This depends on the location, type of building, height etc and should be consulted before installation. Green roofs are increasingly mandatory for new developments. Planning consent can stipulate that the area must blend into the surrounding landscape or mimic the water runoff of nearby Greenfield sites. Green roofs can allow constructors to overcome these terms.
    • Can I choose what plants to have?
      Sky Garden’s seed and blanket mixes have been specifically designed to work well on green roofs. The thin, low nutrient substrate and exposure can make it hard for some plants to grow well. However we do offer bespoke plants and systems, especially on intensive green roofs. For a full quote and design brief for a bespoke system please contact our sales team.
    • Do I need to water my green roof?
      Sedum is used because it is drought resistant and very hardy. Under normal circumstances the roof should not need regular watering. However, live material must be irrigated immediately following installation. This irrigation must continue in the first few months following installation and again in especially hot and dry periods. Sky Garden recommends full saturation of the system once a week in these periods.
    • How much does a green roof cost?
      Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.
    • Does a green roof need maintaining?
      Yes. Green Roofs are 'Low-Maintenance' not 'No-Maintenance'. Green roof maintenance is generally a very simple process. They are designed so that they will not require endless hours spent on the roof in order to keep them looking at their best. Each type of green roof brings many different benefits to the occupants, the owners and the roof itself, so a little time maintaining the system is advantageous in the long run.
    • What access requirements are needed to install my green roof?
      The components of a green roof system can be delivered in m3 sacks, which is the best option for larger builds with crane access. However, on smaller installations with less access 25kg bags can be used and distributed by hand if the transporter cannot get close to the roof.
    • What are the different types of green roof?
      A green roof is any structure that is topped by live vegetation supported by a layer of substrate. Brown roofs are types of green roof that are not initially seeded or covered in pre-grown live material. They are left with the substrate exposed to allow self seeding of the local plants and attract the natural wildlife of the area. Biodiverse roofs can feature areas of seeded, pre-grown blanket or bare ground and are designed to increase biodiversity and create an environment that appeals to the native flora and fauna of the region. Their construction often features piles of logs, boulders or artificial habitats that are designed to replicate the environment preferred by birds, mammals, reptiles and amphibians.
    • What is BREEAM and how can I improve my rating?
      BREEAM stands for Building Research Establishment Environmental Assessment Method and essentially sets the standard for the best practice in design for large scale developments. It is used to assess the environmental performance of buildings and communities. The addition of a green roof can increase the building’s BREEAM rating by making the building more environmentally friendly. You can learn more about BREEAM and green roofs on our Downloads page.
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    Company Brochure

    A comprehensive guide to Sky Garden's green roof systems. Download for detailed information regarding each system available, as well as valuable guidance for maintaining your perfect green roof.


    Biodiversity Brochure

    Download Sky Garden's biodiversity brochure to build your knowledge on the benefits and systems involved in our biodiverse green roof systems.

    Download Company Brochure

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