Cities are known as concrete jungles for a reason: there is more gray than green. This raises important questions about cities' environmental impact and how to combat the effect of dwindling green space. One creative solution is green roofs, which come in various sizes and styles and offer countless benefits, including sustainability, energy savings, and water management.
Here is what you need to know about green roofs and the different types to consider.
What Are Green Roofs?
Green roofs are also often called living or vegetative roofs. As the name implies, they are roofs with vegetation growing on them. Multiple layers support this vegetative layer, including drainage, waterproofing, and root barriers. These roofs are designed to provide various environmental, economic, and aesthetic benefits, including reducing urban heat levels, stormwater management, and increased energy efficiency.
There are a few different types of green roofs, but they generally are made up of the same layers:
Vegetation Layer: The vegetation layer is at the top, where the plants grow.
Growing Medium: The plants are planted in soil or another growing medium, which provides the necessary nutrients to keep the plants healthy and help them grow.
Drainage Layer: The drainage layer helps ensure any excess water is diverted away from the roof
Root Barrier: This layer helps prevent plant roots from penetrating the building's structure, which could lead to severe damage.
Waterproofing Membrane: The base of a green roof is the waterproofing membrane, which protects the roof from moisture penetration.
Types of Green Roofs
There are three main types of green roofs, each varying in weight, maintenance requirements, and the type of vegetation they support. These types include extensive, intensive, and semi-intensive. Understanding each type and its differences is important so that you can choose the green roof best suited for your needs.
Extensive Green Roofs
An extensive green roof is the lightest and most low-maintenance of the green roof systems. It is meant for drought-resistant plants, such as sedums and grasses, which can survive with less soil, requiring only about 2 to 6 inches. This makes extensive green roofs ideal for buildings that have weight restrictions or for retrofitting existing rooftops.
Benefits of extensive green roofs include:
Stormwater Management: They help reduce stormwater runoff by absorbing rainwater and delaying its release into the drainage system.
Improved Energy Efficiency: The vegetative layer of an extensive green roof acts as insulation, helping to reduce heat transfer and improving the building's energy efficiency.
Supports Biodiversity: An extensive green roof also provides a habitat for various insects, birds, and other forms of wildlife, contributing to urban biodiversity and conservation efforts.
Intensive Green Roofs
The next type of green roof option is the intensive green roof. These roofs have a greater soil depth and can support various plant species, including trees and shrubs. However, they require more maintenance and are better suited for roofs with higher load capacities, such as commercial buildings and institutional structures.
Benefits of intensive green roofs include:
More Usable Space: Intensive green roofs can have various uses, including rooftop gardens and recreational areas, creating a space for relaxation, socializing, and gardening.
Better Air Quality: Green roofs help to filter pollutants from the area, improving and enhancing the overall air quality in the surrounding area.
Noise Reduction: The various layers of an intensive green roof act as a noise barrier, effectively reducing exterior noise.
Semi-Intensive Green Roofs
The last of the primary types of green roofs are semi-intensive green roofs, which fall somewhere between extensive and intensive systems in terms of soil depth and maintenance. Soil is generally between 4 to 8 inches in depth, allowing for a wider variety of plant options without the more significant weight or maintenance requirements of intensive roof systems.
Benefits of semi-intensive green roof systems include:
Versatility: Semi-intensive roof systems work with a broader range of plants but require less maintenance, making it a happy medium between extensive and intensive systems.
Visual Appeal: With many more plant options, you can create a more appealing visual display that enhances aesthetics.
Microclimate Regulation: The plans for semi-intensive roofs can help moderate temperature fluctuations, reducing the urban heat island effect and creating a more comfortable and consistent microclimate.
Besides these three main types of green roof systems, there are other types to consider:
Modular Green Roofs
Modular systems are the next of the types of green roof systems that are easy to install and low maintenance. They can contain a wide variety of plants and offer many advantages:
Easy Installation: These systems are easy to install; individual modules can be easily placed and secured to the roof.
Flexibility and Scaling: The modular aspect of these systems makes it easy to expand and modify these types of green roofs, adapting them to fit your needs or the roof's conditions.
Less Maintenance: Pre-grown modules require less time and effort, meaning less maintenance is necessary compared to other systems.
Built-In Solar
As the name implies, built-in solar green roofs offer the benefits of these green roofs and solar energy by integrating photovoltaic panels. Benefits include:
Solar Energy Production: The integrated solar panels allow sustainable, renewable electricity production.
Energy Efficiency: Combining solar panels and a green roof system offers greater energy efficiency, reducing energy consumption through insulation, temperature regulation, and an alternative to traditional electricity.
Aesthetics: The combination also creates an aesthetically pleasing rooftop.
Biodiverse Green Roofs
Another of the types of green roof systems are biodiverse green roofs, which use a wide range of native plants, creating habitats for various organisms and contributing to biodiversity conservation. Benefits include:
Habitat creation: A biodiverse green roof supports an array of plant species that attract a variety of birds, insects, and other wildlife that rely on these urban habitats.
Pollinator support: The wide variety of plants can also include nectar-rich flowers, attracting pollinators and promoting more pollination in urban environments.
Blue-green Roofs
A blue-green roof combines elements of a green roof and a water management system, incorporating features that capture, store, and treat rainwater before it is released into the environment. Benefits include:
Stormwater management: Blue-green roofs help with stormwater management by storing the rainwater in a retention layer that releases it slowly over time, reducing the strain on drainage systems.
Improves water quality: The system's filtration process removes pollutants from water before they are discharged into a water source.
Increased urban resilience: These systems also help enhance a city's resilience to climate change by mitigating flood risks and promoting more sustainable water management.
Using Brava Roofing Tile for a Green Roof
While there are many different types of green roofs, all with different characteristics and varying benefits, one thing that is generally always the same is the need for a durable, waterproof layer to act as the system's base. While there are membranes for this, having a waterproof roof adds extra security. Brava Roofing Tile, a synthetic tile made from recycled plastics, provides the perfect solution with many benefits:
Strength and Durability
Intensive and semi-intensive green roofs require a strong base to support the system's weight. Brava tiles are a lightweight material that offers exceptional strength and durability and can handle the weight of a green roof's various layers without issue.
Energy Efficiency and Insulation
Brava tiles are extremely energy efficient. Their high thermal performance and insulating properties help maintain consistent indoor temperatures. Combined with a green roof, which provides additional insulation and thermal regulation, buildings can significantly reduce heating and cooling costs.
Water Resistance
Again, as stated multiple times, the most important part of a green roof is the waterproofing layers, which protect the roof material and the structure from potential water damage, which could lead to serious issues. You will never have to worry about damage to the tiles caused by rainfall, as the tiles are moisture-resistant and will never rot, mold, or grow mildew.
Sustainability
Brava tiles are made using 100% recycled plastics, keeping waste out of landfills and fitting in with the sustainability of a green roof. The tiles are also recyclable at the end of their lifespan, reducing potential waste and negative environmental impact.
Brava Roofing Tile is the perfect companion to all types of green roofs. These tiles provide aesthetics with styles like cedar shakes, slate, and Spanish barrel tiles while also providing durability and water resistance, two characteristics vital for supporting a green roof. Moreover, the tiles will only enhance a green roof system's sustainability, water management, and energy efficiency.
Contact Brava today to learn more about using these tiles on a green roof.
