The two key elements that contribute to weight are the density of the different layers that make up the green roof and how heavy it becomes as a result of rain absorption.
Minimum weight of green roof.
Weight loading kg m 2 low herbaceous succulents and grasses 10 2.
Sedum vegetation blanket instantly providing at least 90 coverage on an extensive green roof.
Substrate roll is a lightweight green roof substrate manufactured from long mineral wool fibres.
It is a good growing medium and ensures good water absorption and tenacity.
An interesting example of an intensive green roof is manaton the award winning private house on dartmoor that uses local meadow grass to blend the family home into the landscape.
Structural loads weight of green rooftops.
The thickness of the drainage layer will depend on the roof structure and the water storage capacity required depending on the.
Green roof vegetation type.
2 al40 edge trim frames and retains the xf301 system.
The type of green roof in question is engineered to be light and doesn t have typical soil with plants see link above.
Shrubs up to 3 m.
Perennials and low shrubs up to 1 5 m.
There are two types of green roof.
Green roof system weights columbia green technologies 79 se taylor st.
Medium trees up to 10 m.
For example a traditional intensive green roof system for plants and grass featuring at least six layers including soil filter fleece drainage layer and vegetation is.
Saturated with water the weight can increase by as much as 35 to around 100 to 110 pounds per cubic foot.
The company s website lists weights from about 18 psf to a little over 45 50 psf or so.
What contributes to green roof weight.
One cubic foot of dry agricultural dirt or loam typically used for a green roof weighs between 75 and 81 pounds.
Large trees up to 15 m.
Small trees up to 6 m.
Green roof vegetation weight loadings.
3 drainage including filterfleece 11 20 mm.
When it comes to estimating the weight of an existing roof field verification of the in place construction is necessary.
A built up roof for example will typically include the built up membrane itself with or without gravel as well as some kind of insulation and cover board which will vary in thickness from roof to roof.
Intensive green roofs are essentially roof gardens and may also need to allow for the additional weight of paving and terracing furniture and even trees.