Shire Green Roof Substrates Ltd

Shire Ultralite Substrate

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Substrate Description

Lightweight substrate made from secondary aggregates and green waste compost.

Substrate Application

General purpose green roof growing media for green roofs where weight is a concern.

  • Substrate for sedum mat
  • All kinds of extensive green roof, e.g. NBS Q37 Clause 390
  • Simple intensive green roofs, e.g. NBS Q37 Clause 380
  • Small domestic green roofs
Technical Information (Typical)
Size: Sieve Size (mm) % passing Shire minerals ultralite substrate for green roofs 
Photo Courtesy: The Office Group Holdings Ltd
13 96
5 40
pH value: 8.5
Total pore volume: 52 - 60%
Soil Organic Matter (SOM): 6%
Maximum water holding capacity: 43.4% vol.
Driest days in Summer
FLL Maximum
water capacity
Design maximum
m3 490 924 1014
1 sq m @ 100mm 49 92.4 101.4
1 sq m @ 25mm 12.3 23.1 25.35
Packaging: Supplied by bulk tipper load, in multi trip 1 m3 big bags and 25kg sacks

The above information is issued in good faith and without warranty and is intended as a guide only. The information comprises typical data and does not constitute a specification. Specification values are available separately upon request.

The Manufacturing Process

The manufacture of aircrete blocks generates a percentage that do not meet the rigorous quality standards required for house building, for instance because of cracks or other damage and are scrapped. These cannot easily be reprocessed and they are set aside and crushed for use in other applications, e.g. as lightweight aggregates, including use as green roof growing media.

In this substrate the aircrete is blended with lightweight expanded clay aggregate.

Green Compost

Where the growing media incorporates compost it is derived from a sustainable source, normally green waste compost to PAS 100, derived from horticultural wastes collected during municipal works, e.g. hedge trimming, etc.

Shire ultralite substrate used as part of a vegetated roof garden in Bristol

Photo Courtesy: Nicole Gordon, The Office Group Holdings Ltd