Green Roof Weight Per Square Foot

Green roof vegetation type.

Green roof weight per square foot. Medium trees up to 10 m. 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. Weight loading kg m 2 low herbaceous succulents and grasses 10 2. In addition the weight also depends on the water buffering capacity of the drainage layer.

The weight of roofing constructions above the truss rafter may be estimated with the calculator below. Installing a green roof starts at around 10 per square foot for simpler extensive roofing and 25 per square foot for. Extensive green roofs are relatively light at 15 50 pounds 7 23 kilograms per square foot. Thus the saturated weight of a 3 inch deep system is about 20 pounds per square foot including a mature plant cover.

For extensive green roofs up to 150mm 6 in depth no additional structural is usually required. Let s crunch some numbers. 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. None asphalt roll roofing 1 1 lb m ft 2 5 4 kg m 2 asphalt shingle or asphalt fiberglass composite shingle 2 7 lb m ft 2 13 2 kg m 2.

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. Green roofs are usually held in place just by the weight of the grow medium. Extensive green roofs usually exist solely for their environmental benefits and don t function as accessible rooftop gardens. Tray systems are not a viable option for intensive roofs due to the weight.

When fully saturated and with mature plant cover a thin extensive green roof can weigh about 13 pounds per square foot. Weight loads start at 17 lbs. A more typical extensive roof with 3 to 4 inches of growing medium weighs 17 to 18 pounds per square foot and a deeper intensive system can weigh 35 pounds or more per square foot. Small trees up to 6 m.

If necessary this weight can be reduced to approximately 40 kg m for roofs that can only bear a lightweight green roof system. Intensive green roofs weigh from 35 pounds to beyond 100 pounds per square foot when dry it is all a matter of the soil depth which is affected by the amount of mounding that is used. The roof must also be capable of bearing the weight of a garden. Therefor a significant amount of attention must be paid to the various waterproofing and root barrier details.

Ft saturated and increase with the depth of the grow media. Perennials and low shrubs up to 1 5 m. Large trees up to 15 m. Weight of standard sedum roof a standard sedum roof has a saturated weight of about 80 kg m.