Typical extensive roof build up ~
grass/sedum
soil
filter layer or fleece
drainage layer*
waterproof membrane
insulation
vapour control layer
reinforced concrete
roof structure
* typically, expanded polystyrene with slots
147 kg/m^2 saturated weight x 9.81 = 1442 N/m^2 or 1.44 kN/m^2
Typical intensive roof build up ~
filter layer or fleece
drainage layer
water retention fleece
over waterproof membrane insulation
vapour control layer
reinforced concrete
roof structure
Depth to vcl, approximately 560 mm at about 750 kg/m^2
saturated weight. 750 kg/m^2 × 9.81 = 7358 N/m^2 or 7.36 kN/m^2.
plants, shrubs
and grasses
soil substrate
up to 450 mm
Component Weight (kg/m^2 ) Thickness (mm)
vcl 3 3
insulation 3 50
membrane 5 5
drainage layer 3 50
filter 3 3
soil 90 50
turf 40 20
------------- ---------
147 kg/m^2 181 mm
Green Roofs -- Types