Pitched Green Roofs up to 25°

  • Pitched green roof
  • Pitched green roof

Pitched Green Roofs with Slopes up to 25° – How to Prevent Erosion and Transfer Shear Forces Safely

According to general regulations for roofs with waterproofing, flat roofs should have a fall of at least 2 %. Pitched roofs start with a slope of 10° (18 %). From 10° on, the green roof system build-up differs significantly from system build-ups below 10°. Shear forces increase with the roof slope and have to be transferred into stable beams. The substrate layer has to be protected against erosion. Plant selection and planting methods are to be adjusted to the relevant slope and exposure.

A professionally waterproofed roof surface, e.g. with bituminous or highpolymer membranes, is a precondition for a durable long-lasting green roof. The waterproofing should be root resistant and a protection mat with high water storage is needed. Floraset® FS 75, a multi-functional drainage element of expanded polystyrene is the perfect element for pitched green roofs.

It is very important to take the green roof upkeep and maintenance aspects into account at an early stage of planning. Skylights can be installed as access for the maintenance personnel.

Technical Data
Build-up height ca. 130–150 mm
Weight, saturated ca. 115–145 kg/m²
Water retention capacity ca. 38–44 l/m²

Systems for Pitched Green Roofs

General overview of various pitched green roof systems and the technology involved.

Number of pages
18 pages
System Specifications
System build-up



Grafik des Systemaufbaus
Plug Plants “Pitched Roof”
Jute Anti-Erosion Net JEG (> 15° slope)
System Substrate “Rockery Type Plants” ≥ 50 mm above element
Floraset® FS 75
Protection Mat BSM 64

Product Details

Plug Plants “Pitched Roof”

Jute Anti-Erosion Net JEG

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Large-meshed net of 100 % hessian, for the application as erosion protection on areas where humus has just been applied, e.g. on pitched roofs, banks, or slope areas.

System Substrate “Rockery Type Plants”

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Substrate consisting of Zincolit® (sorted high quality crushed brick), enriched with Zincohum (substrate compost enriched with fibre materials).

Floraset® FS 75

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Multi-functional drainage element of expanded polystyrene, applicable for extensive and semi-intensive green roofs on both flat and pitched roofs.

Protection Mat BSM 64

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Synthetic fibre mat with especially high water storage, for the application as a protection layer under extensive and intensive green roof build-ups.

No product information available


The system solution shown relates to the green roof build-up in particular. The roof construction itself is only shown schematically and must be planned and executed according to specialist rules for waterproofed roofs.

  • Dianthus carthusianorum
  • Phedimus hybridus
  • Thymus
  • Gypsophila repens
  • Phedimus floriferus
  • Sedum album
  • Helianthemum nummularium