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Green Roof Substrates

Building a green roof

Green Roof Substrates are specifically engineered for different types of roof greening, both for domestic and commercial projects

Our growing media mixtures have been carefully designed to contain various properties essential for their purpose. For green roof substrates this includes;

Low bulk density
Ability to retain sufficient water for plant growth
Ability to be free draining to prevent saturation
Low nutrient content to prevent excessive plant growth
Sufficient porosity (ensuring good aeration within the growing medium)

All our green roof substrates contain recycled secondary aggregates (like crushed brick) and an organic component (soil / compost), which are blended together in different ratios for various green roof substrate blends.

Extensive Green Roof Substrates are for use on shallow green roof systems (<200mm depth) and are often associated with Sedum mat, Sedum plug plant or wildflower planting.
Intensive Green Roof Substrates are engineered to suit larger vegetation, such as shrubs and trees. Intensive green roofs can be considered “roof gardens”.
Semi Intensive Green Roof substrates have a range of hydraulic conductivity values, allowing them to be utilized in a range of climatic areas
Podium Green Roof Substrates are designed for landscaping projects where weight loading is not an issue. Its high sand content provides a stable growing medium for a wide range of plants.
Extra Light Green Roof Substrates provide an ideal growing media for green roofs where weight loading is an issue.

Our green roof substrate blends are modified to suit the majority of Green roof applications so please get in touch with us for the best substrate for your project.

Our green roof soil substrates have been comprehensively developed and analysed for their chemical and physical properties by STRI. Each substrate blend has been modified for different building requirements and green roof planting schemes. In order to pick the most suitable substrate and installation depth for your project please get in contact with us. Custom substrate mixtures are also available to cater for specific project design criteria.

All our substrates are based on the German FLL and GRO UK green roof guidelines to ensure that all essential properties have been considered and tested. Boughton Loam has supplied substrate for many successful green roof projects all over the country – see our case studies section for more information.