Extensive Substrate to Green Up Your Roof

Roof Substrate "interroof-extensiv"

According to FLL Directive

The roof substrate interroof-extensiv is a ready-to-use, blowable substrate for multilayer construction according to FLL consisting of pumice, lava and compost.

Extensive roof greening is mainly used for roof areas that cannot be used. Due to these locations, undemanding plant species should be used, such as sedum plants.

extensive substrate for green roofs

Field of Application

  • natural roof greening with medium maintenance
  • for sedum sprouts, succulents, herbs and flat-ball plants
  • suitable for flat roofs and garages

Product Description

  • components: pumice, lava and compost
  • structurally stable mineral / organic roof substrate
  • pressure-resistant, segregation-proof
  • optimum tread resistance
  • good structural stability
  • little subsidence
  • provides for hard-wearing green areas
  • good root development
  • good water permeability
  • good water storage capacity
  • better air supply 
  • prevents waterlogging
  • supplies the roots with sufficient nutrients and water
  • buffers the nutrients and promotes growth
  • pH-stable, low salt, long-term stable
  • weed-free
  • suitable for silo trucks, transportable up to 150 m
  • can be processed even in wet conditions and light frost

iNTERBiMS GmbH stands for careful sorting and preparation as well as for the production and supply of high-quality products with a quality management system that meets the requirements of ISO 9001:2015 according to the certificate of TÜV SÜD.


Grain size 0-12 mm

Loose bulk density DIN EN 1097-3

approx. 950-1.000 kg/m³

Paving compaction

approx. 15-20 %

Weight when saturated

approx. 1.400-1.500 kg/m³

Max. water capacity

approx. 35-45 Vol.-%

PH value (CaCI2)

approx. 6,5-7,5

Salt content

approx. 0,1-0,5 g/l

Delivery Form

 ✓   Truck 

 ✓   Big Bag at 1.00 m³ / 1.50 m³

 ✓   Bag of 25 litres / 40 litres

 ✓   Silo truck

Additional external substrates for green roofs

Extensive Substrate Light
Extensive Substrate Light
Extensive Substrate Extra Light
Extensive Substrate Extra Light

About Extensive Substrates for Green Roofs

extensive substrate for green roofs

A green roof looks good and makes a significant ecological contribution to the immediate surroundings and the environment as a whole. A green roof also offers many advantages in terms of construction technology.


For example, a green roof is now often a component of ecological construction. Green roofs compensate for precipitation, as they absorb water like a sponge and rerelease it later. Also, such roofs serve as a settlement biotope for flora and fauna and therefore offer local climatic enrichment.


A green roof with an extensive roof substrate thus shows the following advantages:

  • good microclimate,
  • improved sound and heat insulation,
  • optimal drainage effect,
  • water buffer storage,
  • reduced UV radiation and extended service life of the roof


An essential prerequisite for a green roof is the load-bearing capacity of the roof, as the additional load caused by the greening must be taken into account. For existing buildings, the load-bearing size must be determined beforehand. In the case of new buildings, the greening can be taken into account directly in the planning phase.


Most building owners prefer extensive greening. The roof substrate height is between 5 and a maximum of 15 cm and is suitable as an ecological compensation area. The weight of extensive green roofs is, therefore, up to 150 kilograms per square meter. With intensive greening, the roof substrate heights are much higher and thus lead to significantly higher roof loads.


Green roofs are generally subject to approval. For this, a construction plan must be drawn up, and static calculations must be made. Cities or municipalities can subsidise green roofs. You can find out more about this from the responsible building authority.


Plants of extensive green roofs must be very undemanding. Therefore, mixed cultures of herbs and grasses and other rather low-growing plants should be used here, as they are better adapted to changing site conditions. Thus, undemanding plants such as succulents, greens, herbs or even mosses can be used. Thus one achieves a natural appearance without much care.


With low substrate thicknesses of 2 to 6 cm, moss-sedum plantings are the right choice. These have a high resistance to drought. 

Project Example

Extensive Substrates for Green Roofs
Extensive Substrates for Green Roofs