Green roofs can be traced back thousands of years, the modern version of sustainable roofing emerging in the 1960s. Over the past six decades, green roofs for both residential and commercial buildings have gained popularity in Europe and North America. Also known as living roofs, a green roof is a roofing system that partially or totally covers the surface area with grasses, plants, vegetables, and small shrubs. While there certainly are more advantages, there are some drawbacks to green roofs homeowners should be aware of before investing in this type of roofing system.
An eco-friendly roof helps protect the environment. The release of carbon dioxide into the atmosphere is the biggest contributing factor to global warming. When roofing materials are earth-friendly it means that they aren’t harmful when being produced or used and can be recycled once they’ve reached their lifespan, reducing pollutants released into the environment.
Improves Air Quality
Plants use carbon dioxide as part of photosynthesis. The byproduct of this process is the production of oxygen, which over the long term can improve air quality.
Reduces Energy Consumption
The vegetation on a green roof absorbs heat and sunlight. In summer, this process cools the roof, significantly reducing the amount of energy required to cool the inside of your home on a hot August afternoon. Because the “roofing shingles” are plants and ground cover, in winter this mini ecosystem functions as insulation and you won’t need as much energy to heat the house. It also provides year-round insulation, reducing your family’s carbon footprint.
Reduces Noise Pollution
Particularly if you live near an industrial park, a busy highway, a school, or in a neighbourhood with lots of children, an eco-friendly roof can absorb sounds that might be disruptive to a household.
Adds Value to Your Home
An earth-friendly roof can add value and enjoyment, providing another place to relax and enjoy the view while growing fresh herbs and salad greens for dinner. When it comes time to move, additional usable space will be attractive to potential buyers. And sustainability is a definite selling point – many homeowners look for ways to make the world a more habitable place through sustainable living practices.
Increases Curb Appeal
A green roof will be unique to your home, adding character and personality to your property. Even if other houses in the neighbourhood have living roofs, the chances of several homes having the same style, type of vegetation, and design are slim. Green roofs tend to blend in with the surrounding environs, even in an urban setting, creating harmony that is both appealing and welcoming.
Disadvantages of Green Roofing
While there are several advantages to installing a green roof on your home, there are also some drawbacks. These include:
- High cost – the initial expense of designing and installing a green roof is high
- Maintenance – a living roof needs to be well-maintained in order for the plants and native grasses to thrive and stay healthy
- Risk of damage and leaks – if plant roots penetrate the waterproof membrane roof leaks and structural damage can result
- Heavy – depending on the type of green roof, it can add significant weight to the rooftop
Decide If a Green Roof is Right for You
Choose the type of sustainable roof that best suits your home. The three kinds of living roofs are: extensive (thin or shallow layer of soil covering a large area), intensive (deep layer of soil covering a small area), and semi-intensive (a mix of both).
You can install a living roof if the slope of the roof is flat or not sloped more than 30 degrees.
Regardless of the type of sustainable roof you choose, have the house inspected to ensure its structure can support the weight of vegetation being rained on (wet soil).
You will still need gutters and downspouts to provide proper drainage for your living roof.
Green roofs require vigilant maintenance – be prepared to regularly inspect (DIY or a roofing contractor) the roof for leaks and potential problems.
This might sound like the ultimate do-it-your-self project but a lot could go wrong. Plan to hire a professional green roofer with at least seven years experience in designing and installing living roofs.
A green roof is attractive to wildlife – any creature from as small as an ant to as large as a raccoon. Ensure you select plants specific to your region to help minimize species that attract common pests.
Even in the planning stage, it would be useful to discuss pest control strategies so that you have some idea of what would be involved should you have a problem.
A green roof can be high maintenance. If you’re a gardener you know the drill, but if your gardening skills are limited to pulling weeds and mowing the yard be aware of the time commitment a living roof will require.