What is the difference between an extensive and intensive green roof?
This is the easiest way to remember the difference – an extensive green roof probably has a shallow layer of substrate that covers a large area, whereas an intensive green roof often has a deeper layer of substrate, confined to smaller areas.
What is an intensive green roof?
Intensive green roofs require the deepest soil and have the greatest impact on the structural design, but they also accommodate all types of plantings including large shrubs and trees. Intensive systems allow the designer to create a park-like setting so they are the best option for roof gardens that will be occupied.
What is extensive roof?
Extensive landscaped roofs are an ecological alternative to conventional surface protection or ballast layers such as gravel and pavers. They are lightweight and have a shallow build-up height. Suitable plants include various Sedum species, herbs and some grasses.
What are the 3 types of green roofs?
Green roofs are also known as vegetative or eco–roofs. They fall into three main categories—extensive, intensive, and semi–intensive.
How thick is an intensive green roof?
G-1 Extensive green roofs have a much shallower growing media layer that typically ranges from 3 to 6 inches thick. G-2 Intensive green roofs have a growing media layer that ranges from 6 to 48 inches thick.
How do you make a green roof intensive?
With the decking in place, here are the steps to installing a green roof:
- Install Waterproof Membrane. Install a monolithic type waterproof membrane (rubber or plastic) on top of the roof decking.
- Put Down Plastic Sheet.
- Add Foam Installation.
- Set Drainage Mat.
- Frame the Sides.
- Add Soil.
- Place Plants.
- Water.
What is intensive roof?
An Intensive Green Roof or Roof Garden includes unlimited plant and design varieties. Likewise in open space planning, which allows any form of vegetation. Intensive greening may consist of perennials, grasses, bulbs, summer flowers, shrubs and large trees.
How deep is an intensive green roof?
The soil depth of an intensive green roof typically ranges from 12–36+ in. An intensive green roof is the most expensive, but also has the highest capability to mitigate stormwater runoff and insulate a building.
What is semi intensive green roof?
Definition. A semi-intensive green roof system is characterized by small herbaceous plants, ground. covers, grasses and small shrubs, requiring moderate maintenance and occasional irrigation. A typical growing medium depth for a semi-intensive green roof is 15 to 30 cm.
What are the two types of green roof?
There are two primary forms of green roofing: intensive and extensive. These are differentiated by the amount of vegetation utilized. While extensive green roofs can support up to 25 pounds of vegetation per square foot, intensive green roofs can hold 150 pounds per square foot.
Can you walk on a green roof?
Yes, you can occasionally walk on a Sedum roof. For instance, when you fertilize the roof once a year, walking on the Sedum plants is not a problem. However, be careful if it freezes: it is not advisable to walk on the vegetation if the plants are frozen, you may damage them.
Do green roofs need drainage?
Water retention is essential for green roofs
It helps to make sure that the plants have enough water – but not too much. Sedums like good drainage but they do need some water to survive.
How thick are intensive green roofs?
What are the disadvantages of green roofs?
Disadvantages of green roofs
- A greater expense than traditional roofs. Unfortunately for green roofs, they do tend to be slightly more expensive than the traditional option.
- An increase in weight load.
- Require extra maintenance.
Do green roofs need to be watered?
Extensive green roofs typically don’t require built-in irrigation systems in most regions. However, during periods of prolonged drought, the extensive green roof should be watered to sustain plant health.
Do green roofs need maintenance?
An extensive green roof is almost maintenance free. But your roof garden will always need a little maintenance. This includes removing weeds carried by the wind and applying fertilizer several times a year. You will not damage the plants by walking on them when conducting this maintenance.
Do you mow green roof?
No, vegetation blankets are easy to maintain. If desired, vegetation blankets can be pruned, but this is not necessary.
What is one disadvantage of a green roof?
Disadvantages of a Green Roof
A green roof will be more expensive to install than a traditional flat roof, as the underlying structure may have to be strengthened to cope with the extra load. Green roofs offer so many benefits that you would be crazy not to consider an installation in an appropriate area.
How do you maintain an intensive green roof?
Annual maintenance
Inspect the green roof at least 5 times a year for weeds and seeds (carried by the wind) and remove these manually. Do this preferably in the spring, before the weeds begin to flower. To encourage biodiversity, we do not recommend the use of chemical pesticides.
How thick does a green roof need to be?
The effective depth of the drainage layer is generally 0.25 to 1.5 inches thick for extensive green roof system and increases for intensive designs.
What are two drawbacks of green roofs?
Although green roofs have advantages that speak for themselves, there are still a few drawbacks that you should keep in mind before investing in a green roof.
- A higher cost than traditional roofs.
- Weight load increase.
- Needs extra maintenance.
- Requires a tedious effort.
How often do green roofs need to be replaced?
A green roof can have an average lifespan of 50 to 75 years (or maybe even more—it’s not like they’ve been around for very long!). Given the potential longevity of a green roof, it’s of the utmost importance that you do extensive research and choose a design that you like.
Do green roofs require maintenance?
Maintaining your green roof. An extensive green roof is almost maintenance free, but your roof garden will always need a little maintenance. This includes removing weeds carried by the wind and applying fertilizer several times a year. The plants will not be damaged by walking on them when conducting this maintenance.
How do you maintain an extensive green roof?
A typical extensive sedum or meadow roof will only require limited maintenance. Once or twice a year to weed and feed should be sufficient. Keeping edges tidy and gutters clear will help stop damage to your roof and the underlying building.