What Is a Green Roof?
A green roof is also known as a living roof. It’s a roof of a building that is partially or completely covered with vegetation such as plants. They are planted over a waterproof membrane. A green roof is not something we necessarily do — yet, but we are interested in the concept and wanted to share it with you.
Environmental Benefits of a Green Roof
- Green roofs have a variety of environmental benefits. Some of the following are:
- Makes it cooler by 50 to 90%.
- Absorbs heat and acts as an insulator for buildings, reducing energy needed to provide cooling and heating.
- Reduces air pollution and green gas emissions. Because it lowers air conditioning demand, green roofs decrease production of air pollution and greenhouse gases. The vegetation can also remove air pollutants and greenhouse gas emissions through dry deposition and carbon sequestration and storage.
- Filters pollutants and heavy metals out of rainwater.
- Helps to insulate a building for sound. The soil helps to block lower frequencies and the plants block higher frequencies.
Other Benefits of a Green Roof
- Last longer than standard roofs.
- Create an additional outdoor space if the roof is flat.
- Take care of rain water, acting as a highly effective drainage system.
- Protects the building from the elements.
- Requires very little maintenance.
- Improves air quality.
- Enhances the beauty of the space.
Types of green roofs
Green roofs fall into two distinct categories: extensive and intensive. Intensive green roofs are akin to elevated parks. They contain shrubs, trees, walkways, benches and have a complex structural support. They also have irrigation, drainage and root protection layers. This can create a load of up to 150 lbs per square foot. Extensive green roofs, on the other hand, are relatively light. They only add 15-50 lbs per square foot. They support native ground cover and require only a little maintenance. Extensive green roofs exist for environmental benefits. They are not functioning as accessible rooftop gardens.
Green roofs initially cost double to install than a normal roof installation due to the necessary structures that need to be put in place to support the vegetation plus the cost of the vegetation itself. Maintenance costs depend upon the type of plants you have on your green roof and can be minimal to fairly extensive.
A green roof is best found on a flat surface so not a lot of homes or other buildings can support a green roof. However, those that can can help reduce the heat of the urban landscape and make air conditioning less necessary for themselves and their neighbors.
Green roofs have many benefits but they are not for everybody.
If you want to talk more about the type of roof that will work best for your building, call us at 21st Century Painting & Roofing at 512-219-0342.