Types of Green Roofs

In simple words, a green roof is a layer of vegetation on the top of a flat or sloped platform, mostly roofs. Also known as vegetative or eco-roofs, they are installed over waterproof roofs. The vegetation is generally in the form of grass, small plants, flowers, and in some cases, even trees. Based on the thickness of the soil layers, green roofs are often categorized into extensive, intensive, and semi-intensive.

5 Types of Green Roofs

Types of Green Roof

In the wake of climate change, coupled with the requirement of adhering to a more sustainable and eco-friendly cooling alternative, the importance of green roofs is now being realized by people. Moreover, you may have noticed that, in general, people like more of a green environment to live in than concrete structures, and green roofs are one of the solutions to this problem.

Let’s have a look at the primary benefits of green roofs.

1. Intensive Green Roofs

This is the most expensive and the heaviest variant of the green roof. In this type of green roof, we use perennials, shrubs, and trees, and the depth of the substrate varies between 150 to 400 millimeters. Besides, it exerts an enormous weight on the surface, ranging between 180 to 500 kilogram per meter square.

2. Semi-Intensive Green Roofs

In this variant of green roof, we use grass, herbs, and shrubs to cover the roof of the building or the apartment. With periodic expenses associated with it, it is slightly more expensive than the extensive green roofs. Besides, the depth of the substrate varies from 120 to 250 millimeters. It exerts an additional weight of 120 to 200 kilogram per square meter.  

3. Extensive Green Roofs

To begin with, in extensive green roofs, we use moss, herbs, and grasses to cover the roof. Depending upon the area of the roof, the depth of the substrate is between 60 to 200 millimeters. Therefore, it is the cheapest green roof and is quite easy to maintain, and this type of green roof exerts only an additional weight of 60 to 150 kilogram per square meter. 

4. Blue-Green Roofs

In the case of conventional green roofs that use a standard drainage layer to provide lateral drainage and irrigation, blue roof technology works to increase both the amount of stored water and the amount of water that is released.

5. Bipolar Green Roofs

As the name implies, this combines green roofs along with solar panels. Depending on the area of the green roof, this technology is further developed to maximize biodiversity, enabling certain birds and insects to thrive well in an urban setup.

Benefits Of Green Roofs

Benefits of Green Roofs

In the wake of climate change, coupled with the requirement of adhering to a more sustainable and eco-friendly cooling alternative, the importance of green roofs is now being realized by people. Moreover, you may have noticed that, in general, people like more of a green environment to live in than concrete structures, and green roofs are one of the solutions to this problem.

Let’s have a look at the primary benefits of green roofs.

1. Air purification

The plants planted on the green roofs release oxygen and, in turn, absorb some carbon dioxide from their immediate surroundings. This, in turn, cleanses the air around itself. This is one of the primary benefits of installing a green roof. In today’s world, lack of vegetation, especially in the urban areas, is one of the biggest challenges, and this can be a little contribution to your immediate environment.

2. Saves Rainwater

Needless to say that rainwater which falls on our roof is wasted, as in most cases, we are unable to save that water. But if you install a green roof, the soil absorbs a lot of water used up by the plants and delays the rainwater from being wasted through the drainage system. This, in turn, reduces the chances of overflowing the drainage system, which is one of the major challenges of urban areas, and this reduces the propensity of flooding local areas.

3. Reduces The Temperature Of The Room/Building

A green roof absorbs most of the sunlight while the rest of the sunlight is reflected. This cools down the area’s temperature, and the temperature of the room is reduced to a great extent. Even having an air conditioner will save energy and electricity, as the room temperature will be much lesser. 

4. Increases The Lifespan Of The Roof

Although installing a green roof may be a little more time-consuming and comparatively expensive, it protects the materials used in the roofs from most of the external influences like the Sun, rain, and wind. Therefore, in the long run, the roof’s life span is much longer than the traditional roofs, which deteriorate earlier due to these factors.

5. Attracts Biodiversity

In its entirety, a green roof acts as the natural habitat for a host of insects and birds, and if you have a good collection of flowers, you will also find butterflies on your terrace. Of course, this increases the aesthetic appeal of your building, especially if you live in an urban area, but it also enables these birds, insects, and butterflies to thrive and prosper.

6. Reduces Noise Pollution And Makes Your Roof Fire-Resistant

Plants are excellent absorbers of any sound and this, in turn, reduces noise pollution in and around your house or apartment. Besides, with green roofs, there is a natural layer of soil, and the plants that grow on it have a lot of moisture. And both these factors combine to create a natural layer that is fire-resistant and can save your house from any potential fire hazards. 

What Are The Disadvantages Of Green Roofs?

Despite the advantages that have been discussed about green roofs, there are some disadvantages of the same. Let us have a look at them.

1. It’s more expensive

Green roofs are comparatively more expensive than traditional roofs. The major reason for this is the additional support that is required for handling the increased load on the roof. But, although there is a more initial expense, over the years, owing to the roof’s longevity, you will find that there are benefits to installing a green roof.

2. There Is More Load

Needless to say that a green roof is bound to be heavier than a traditional roof owing to the weight of the layers of soil and the plants which grow there. Moreover, there is substantial structural support, which adds to the weight of the same.

3. The Time-Consuming Process Of Maintenance

Apart from the regular activities of watering and weeding, you will also have to keep your green roof free from pests and unwanted insects. Besides, you will also have to continuously monitor the condition of your roof and ensure that your property is not becoming vulnerable to any damage from water leakage.

4. Requires Constant Maintenance

It requires continuous maintenance work to make a green roof thrive and prosper. A green roof is no less than a garden in itself, and it will require watering and weeding from time to time. If you are passionate about gardening, you may undertake the task of maintaining the green roof yourself. Otherwise, you may need to hire somebody to take care of your green roof, which can add to the expense of maintaining the same.

What To Keep In Mind While Green Roofing Your Home?

There are certain standards regarding the design of a green roof, and you should keep them in mind. Maintaining a few do’s and don’ts will ensure that your green roofs last for many years without any major issues or huge maintenance costs.

1. Wind Uplift

You don’t want your green roof to face the wrath of the wind uplift, which, apart from ruining your green roof, can also harm your home. If there is a lot of air pressure below the green roof, it can lead to a pressure shift, which may rip off the greenery from your roof. This will destroy the green roof of your house. 

2. Your Green Roof Can Catch Fire

While it is true that green roofs, in general, can reduce the chances of your home catching fire by forming a protective layer on the roof, there is still a risk of the vegetation catching fire. If there are lots of uncleaned dry twigs, the chances of fire are even more. Besides, natural events or occurrences can also make the green roof catch fire. There are established fire designs to deal with this problem, which you can use to keep your house safe.

3. Protect Your Home From The Roots Of The Plants

This is one of the most serious issues that you should consider while installing a green roof at the top of your house. The roots of the plants, especially that of the trees, can burrow deep through the roof of your house. As a result, they can tear up through the concrete and thus jeopardize the internal strength of your house. To deal with this problem, certain established procedures, like the VR-1 procedure, provide guidelines on checking the danger and their remedies. But it would be great if you also kept in mind that these remedies are for short-term effects and must not be used to study any long-term repercussions.

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About Jennifer Igra

Growing up in Brooklyn, New York City known for it’s green gardens. Jennifer, a 30 year old gardener and green living fanatic started Igra World to share her gardening journey and increase gardening awareness among masses. Follow Igra World to improve your gardening skills.

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