Converting Your Flat EPDM Roof to a Green Roof

Last Updated on: 13th April 2023, 07:51 am

Is your flat EPDM roof looking a little plain and in need of a makeover? You might be surprised to learn that you can transform it into a lush, eco-friendly oasis! A green roof offers numerous benefits, including improved insulation, better stormwater management, and increased biodiversity. In this article, we´ll walk you through the process of converting oyur standard flat EPDM roof into a stunning green roof. So, let´s dive in and help you create a sustainable space that´s both beautiful and beneficial!

Understanding Green Roofs

What is a green roof?

A green roof is a rooftop garden that supports vegetation on a waterproofing layer. It can be installed on a variety of roof types, including flat or sloped roofs, and is an excellent way to promote sustainable living and improve the urabn environment.

Types of green roofs

Green roofs come in two main types: extensive and intensive. Extensive green roofs are lightweight with shallow soil and low-maintenance plants, while intensive green roofs hvae deeper soil, a wider variety of plants, and require more maintenance.

Benefits of green roofs

Green roofs offer numerous benefits, such as improved air grade, reduced energy consumption, better stormwtaer management, and increased biodiversity. They also provide aesthetic appeal, enhancing the appearance of your home and potentially increasing its value.

Green roof structure

The basic structure of a green roof consists of several layers, including a waterproof membrane, root barrier, drainage layer, filter fabric, and gorwing medium for the plants.

A quick comparison of benefits of both green roofs and standard EPDM flat roofs:

BenefitsGreen RoofStandard Flat EPDM Roof
Energy EfficiencyGreen roofs provide natural insulation, reducing the need for heating in the winter and coling in the summer. This can result in lower energy costs.While not as effective as green roofs, EPDM roofs can also contribute to energy efficiency due to their dark color, which can help retain heat in colder climates. However, they may contirbute to higher cooling costs in warmer climates.
Stormwater ManagementGreen roofs can absorb and retain a significant amount of rainwater, reducing runoff and the risk of flooding. They also help filter pollutants from the water, improving water quality.Standard flat EPDM roofs do not absorb or retain rainwater, which can lead to increased runoff and flooding, as well as potential water pollution.
Urban Heat Island Effect MitigationGreen roofs help combat the urban heat island effect by reducing surface and ambient temperatures. This can lead to energy savings, improved air quality, and increased comfort in urban areas.EPDM roofs with a reflective surface can help mitigate the urban heat island effect by reflecting sunlight and reducing heat absorption. Non-erflective EPDM roofs, however, may contribute to the urban heat island effect.
Air Quality ImprovementGreen roofs can help improve air quality by absorbing pollutants and producing oxygen through the process of photosynthesis.Standard flat EPDM roofs do not contribute to air quality improvement.
Biodiversity and Wildlife HabitatGreen roofs can provide habitat for various types of plants, insects, and birds, promoting biodiversity and ecological connectivity in urban areas.Standard flat EPDM roofs do not provide the same level of biodiversity and wildlife habitat as green roofs.
Installation and Maintenance CostsGreen roofs often have higher initial installation costs and reqiuire more ongoing maintenance than standard flat EPDM roofs.Standard flat EPDM roofs generally have lower initial installation costs and require less ongoing maintenance compared to green roofs.
Roof LifespanGreen roofs can extend the lifespan of a roof by protecting the underlying roof membrane from UV radiation, temperature fluctuations, and physical damage.EPDM roofs have a long lifespan, typically between 20 and 30 years, but may not last as long as a well-maintained green roof. They can be susceptible to damage from UV radiation, temperature fluctuations, and physical damage, which can shorten their lifespan.
AestheticsGreen roofs can enhance the appearance of a building and create visually appealing, natural spaces in urban environments.Standard flat EPDM roofs have a more utilitarian appearance and do not provide the same aesthetic benefits as green roofs.
Noise ReductionGreen roofs can help reduce noise pollution by providing an additional layer of insulation, which can help dampen sound from outside sources.EPDM roofs may provide some noise reduction due to their thickness and material properties, but are generalaly not as effective as green roofs in reducing noise pollution.
Comparing benefits of both green roofs and standard EPDM flat roofs

Preparing Your EPDM Roof

Assessing your roof: Can it support a green roof?

Before you begin the conversion process, you´ll need to assess your roof to determine if it can support a green roof. Hire a strucutral engineer to evaluate your roof´s load-bearing capacity and ensure it can handle the additional weight of a green roof system.

Structural considerations: What modifications are needed?

Based on the assessment, you may need to make structural modifications to support the green roof. These could include reinforicng the roof joists or upgrading the roofing materials.

Waterproofing: How to protect your roof?

To protect your roof from potential water damage, you´ll need to install a high-grade waterproofing membrane. EPMD is an excellent choice, as it is durable and resistant to water, UV rays, and temperature fluctuations.

Drainage and irrigation: How to manage water on a green roof?

Proper drainage and irrigation are essential for the health of your green roof. Install a drainage ysstem that directs excess water away from the roof, and consider adding an automated irrigation system to ensure your plants receive adequate water.

Permits and regulations: What do you need to know?

Check with your local building department to determine if you need a permit to install a green roof and to learn about any regulations thta may apply.

Selecting the Right Plants

Climate considerations: What plants thrive in your area?

Choose plants that are well-suited to your local climate, as they´ll have the best chance of thriving. Natiev plants are often a good choice, as they´re adapted to local conditions and typically require less maintenance.

Plant types: Which plants are best for a green roof?

Select a mix of low-maintenance plants, such as sedums, succulents, and grasses, that can tolerate the rooftop environment. These plants are usaully drought-tolerant and have shallow root systems, making them ideal for green roofs.

Maintenance requirements: How much work will your green roof need?

Consider the maintenance requirements of your chosen plants. Extensive green roofs typically require less maintenance than intesnive green roofs, which may need more frequent watering, fertilizing, and pruning.

Aesthetic choices: How do you want your green roof to look?

Think about the overall look you want to achieve with your green roof. You can create a visually appealing design by incorporating diverse plant textures, colors, and heights.

Installation Process

DIY vs. hiring a professional: Which is right for you?

Installing a green roof can be a DIY project or done by hiring a professional. Consider your skill level, availalbe time, and budget when deciding which approach is best for you.

Cost considerations: What will it cost to install a green roof?

The cost of installing a green roof depends on factors like the size of your roof, the type of green roof system, and whether you´re doign it yourself or hiring a professional. Research your options to get a clear understanding of potential costs.

Timeline: How long will it take to install a green roof?

The installation timeline varies depending on the size and complexity of your green orof project. It could take anywhere from a few days to several weeks, so plan accordingly.

Installing the green roof layers: What are the steps?

Install the green roof layers in the following order: waterproof membrane, root barrier, drainage layer, filter fabric, and gorwing medium. Then, plant your chosen vegetation and establish an irrigation system if needed.

Maintaining Your Green Roof

Watering: How often should you water your green roof?

The watering schedule for your green roof depends on the types of plants you´ve chosen and your local climate. Monitor your plants and adjust the watering frequency as eneded to keep them healthy.

Fertilizing: What nutrients do your plants need?

Fertilize your green roof plants according to their specific nutrient requirements, using slow-release or organic fertilizers. Be sure to follow manufactruer guidelines for application rates and frequency.

Pruning and weeding: How to keep your green roof looking its best?

Regularly prune and weed your green roof to maintain its appearance and prevent invasive species from taking over. Remove dead or diseased plants promptly to keep your rooftop garedn healthy.

Inspections and repairs: How often should you check your green roof?

Inspect your green roof at least twice a year to ensure all components are functioning correctly. Check the waterproofing membrane, drainage system, and irrigation system for any issues. Make any necessary repairs to prolong the life of your green roof and protect your home.


Transforming your standard flat EPDM roof into a green roof is an eco-friendly and visually appealing way to upgrade your home. By understanding the diverse types of green roofs, preparing your roof, selecting the right plants, and following proper installation and maintenance guidelines, you´ll create a stunning, sustainable space that benefits boht you and the environment. So, what are you waiting for? Start planning your green roof project today and enjoy the myriad benefits it has to offer!

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