Green roof vs. traditional roof
When you hear the term “green roof” you might get several definitions, from using roof coatings to preserve a roof, which reduces the amount of roofing material being thrown away, to actual vegetation installed on a roof as a source for energy efficiency, improved air quality, and better management for water runoff.
For the most part, when talking about green roofs here, we’re thinking of roofs with vegetation grown on the top layer. While much more common in Europe, interest is increasing over green roofs in the U.S. for both residential and commercial roofs as environmentally friendly alternative to traditional roofing systems like shingles or tile.
When it comes to comparing green roofs vs. traditional roofs, green roofs offer quite a few advantages, especially if you are interested in making your home or business more environmentally friendly.
Because of their unique design, green roofs manage water runoff better than traditional roofs because the plants on a green roof will absorb the water. Green roofs also tend to be more energy efficient than traditional roofs, serving as a source of heat absorption. These roofs are also known to improve air quality both inside and outside of the home or office.
On the other hand, depending on the system, green roofs tend to cost more to install than many traditional roof systems, especially asphalt shingles. But, these initial costs are offset by long-term cost savings, not only through energy savings but for lower maintenance costs as well.
Some newer innovations in traditional roofing such as synthetic shingles offer environmentally friendly aspects, especially when it comes to longevity and the ability to recycle the material used in the roofing system.
Are green roofs cost effective?
Once installed, green roofs can prove very cost-effective. In fact, depending on system you install, the initial installation of a green roof is usually one of the most costly aspects of a green roof.
These initial costs are often offset by the long-term benefits. Depending on the size of the system, green roofs are generally low maintenance. You basically have a garden on your roof, so some of your primary expenses will be the same as upkeep for a garden.
One big advantage to green roofs, according to recent studies, is that they can improve the lifespan of the roofing membrane, almost doubling it compared to a traditional roof. Green roofs protect the roofing membrane the stress caused by high temperatures and reduce daily temperature fluctuations.
Do green roofs need drainage?
While much of the water from precipitation will be absorbed by the plants on a green roof, the roof still needs a drainage system to drain off the excess water. Excess water has to be drained to keep the plants from becoming waterlogged and oxygen-depleted, and to protect the roof’s structure.
Do green roofs provide insulation?
Green roofs are known for their energy efficiency. While technically green roofs have little or no actual insulating effect on the roof’s R-value, or the measurement of how well a material resists the flow of heat, green roofs do effectively absorb heat, creating a buffer against temperature fluctuations. Their surface temperature usually stays the same as the outside air temperature. They also provide shading to help with cooling. It’s these aspects that make green roofs valued for their energy efficiency.
How do green roofs work?
You have two main types of green roofs, extensive and intensive. An extensive roof uses a thinner layer of soil than an intensive roof and usually houses plants like mosses, while intensive roofs allow for larger plants, including trees. These types of roofs work best for low sloped roofs. Both kinds, however, work essentially the same.
Like a regular roof, a waterproof roofing membrane is installed, and occasionally insulation is installed. A layer of soil for the plants is added over the roofing membrane and acts similarly as shingles might for a traditional roof. The plants on a green work in part to help absorb water, although excess water will require a drainage system to drain off. The green layer also aids in heat absorption and reducing the home’s heating and cooling needs.
How are green roofs energy-efficient?
As above, green roofs help maintain energy efficiency primarily through heat absorption, shading and regulating temperature fluctuations. One study indicates that even small green roofs can reduce energy demands in the summer by 75%.
While green roofs are built for both residential and commercial roofs, you may want to consider a green roof for your business.
Here are some reasons you might consider green commercial roofing:
- Energy efficiency: Green roofs help reduce heat and cooling costs through heat absorption and temperature regulation.
- Improved air quality: Dust and pollutants are removed from the air and oxygen are increased.
- Preserves roof: The roofing membrane is protected from the heat and UV radiation and the roof’s life is extended. It’s also protected from reduced wear from drainage.
- Visual appeal: Can provide a more positive space for employees
Green commercial building ideas
Besides green roofs, commercial buildings can become more eco-friendly in other ways, including going solar, one of the best sources for clean and low-cost energy. Roof coatings specifically designed to cool your roof can help reduce energy costs. You can also opt for other roofing systems that are much more environmentally friendly like synthetic shingles or even single-ply roofing like PVC membranes that are recyclable. Using recyclable materials in your building is another way to be eco-friendly.
When considering environmentally friendly building options, you may also want to look into the health and well-being of your employees. One way to do this is by installing a water softener for clearer, healthier water.
Green roof and sustainability
Besides all the benefits mentioned above, green roofs also benefit the environment, especially in dense urban areas by reducing the Urban Heat Island Effect. Urban areas tend to trap heat more than rural areas and green roofs help reduce this by absorbing the heat.
Interested in green roof installation in Raleigh, NC? See what Roofwise can do for you to make your roofing system eco-friendly. Give us a call at 919-823-6253.