How Much Does A Green Roof Weigh

Biodiverse green roofs are low maintenance roofs designed to create or replace natural habitats.

How much does a green roof weigh. The weight of biodiverse green roofs varies according to the needs of the plant species required. How much does a green roof cost. Holds up to 9 litres of water per square metre so saturated weight is 9kg m2. Weight of standard sedum roof a standard sedum roof has a saturated weight of about 80 kg m.

As a guide prices can vary from 50 m for a sedum roof to 200 m for a fully planted intensive roof the cost of any reinforcement needed to the roof and or wall structures is additional to this. Thus the saturated weight of a 3 inch deep system is about 20 pounds per square foot including a mature plant cover. 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. The cost will vary with the green roof system and the particular situation.

Typically a basic lightweight green roof will weigh between 60 to 150 kg per square metre which will increase when saturated with rain or snow. Check that there are no areas of damp rotting wood. They can be specified to meet local biodiversity action plans or to support specific flora and fauna including bats bees butterflies birds and so on. When saturated with water in the summertime when the plants are at their biggest and heaviest the mats weigh 40 45kg m2.

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. So in dry state 50 m2 traditional green roof weighs around 5 tons while a similar sized urbanscape roof weighs just 1 ton scale this up and a 1 000 m2 traditional green roof space requires 100 tons of material to be brought on the roof and the urbanscape version only 20 tons and can be called a light weight green roof. For example roofmeadow green roofs engineered to be both lightweight and efficient generally weigh about 6 75 pounds per square foot for each inch of media depth. A flat roof built using the enviromat green roof system will weigh the following.

Let s crunch some numbers. On average an extensive green roof weighs between 10 30 lbs per square foot. And an intensive green roof weighs between 50 300 lbs per square foot.