Do Green Roofs Really Work?

completely finished green roof

Updating Your Roof

A green roof isn’t referring to the color of a roof anymore. It is a roof that has living plants thriving on top of it. They are common in Europe, where they learned the benefits that having a green roof provide not just the structure it’s on, but the surrounding area too. There are many possible reasons to consider a roof like this. For more information about a green roof for your Cincinnati, OH, give us a call at 513-342-8544.

What is the benefit of a green roof?

There are several green roof benefits, some directly to the building and others that affect the nearby area, like less footprint left behind.

  • Provide insulation for structures and reduces cool costs
  • Reduces urban heat effect
  • Improves air quality
  • Increase of native plant varieties
  • Provides a refuge for endangered birds
  • Improves marketability and property value
  • Green roof drainage minimizes storm water runoff and water retention
  • Improves efficiency of mechanical equipment
  • Extends roof lifespan
  • Provides pleasant environment view for occupant enjoyment and meetings 
  • Tax benefits

 If planting a green roof isn’t possible for your structure, another option for a green roof vs traditional roof is applying roof coatings. For a flat roof structure where a green roof of plantings isn’t possible, applying an EPDM, PVC, or rubber type coating is considered a version of green roof. 

How long does a green roof last? 

Having a green roof has been the standard in Europe since the 1960s.  A green roof will protect the original flat roof membrane, extending its life up to 50 years, with 40 years being the average.  Factors that come into play determine the life span of a green roof is the health of the original roof, how well the green roof is maintained, and the normal climate and environment concerns for any roof. Within the estimated forty years, a green roof can save the owner as much as $200,000 in energy expenses. 

green roofing with sitting area

Do green roofs leak?

When you compare a green roof to a traditional roof, it isn’t any more prone to leaking. It isn’t what is on top of the roof that determines if it will leak or not, but the structure’s design and integrity. To make sure a green roof doesn’t leak, it needs proper drainage and waterproofing membrane, just like a traditional roofing.

Studies have proven that a green roof will give a roof a longer lifespan than a traditional roof because it protects it from the sun’s ultraviolet rays. Not that a green roof doesn’t have its faults, though. 

The first downside to a green roof is the expense. When compared to the installation of a traditional roof, a green roof costs more, but it also has a higher ROI. Another downside to a green roof is the increase of weight on the structure. This is often part of the higher expense to install is having the structure reinforced. A green roof requires more maintenance than a green roof. A green roof requires feeding, watering, and weeding. With the right type of plants, you can minimize that maintenance. 

Do green roofs need maintenance?

A green roof is like any garden, there is some maintenance required. How much maintenance will depend on the type of green roof you plant. The more intensive the roof garden, the more maintenance it will require. The climate and environment will factor into the amount of maintenance needed.

How do you maintain a green roof?

There aren’t any simple instructions on green roof maintenance, but some basic green roof maintenance tips:  

  1. Weed the unwanted plants out, this is especially important the first season. If they are allowed to grow and run free, the plants will be crowded and kill them out.  
  2. Keep drainage free of debris and plants. If debris and plants cover the drainage, the garden roof can’t drain.
  3. Compost should be added biannually with nutrient-rich compost. Autumn and spring are the recommended time of the year.  
  4. Time to weed the unwanted plants out again! Birds and wind will blow seeds of other things on to a green roof, and not all of them are things you want. A monthly walk through your roof garden suffices to inspect and monitor your green roof and pull out the unwanted growth.  
  5. A green roof won’t need as much watering as a traditional garden, the biggest reason is the added weight that can add to the structure. Choose plants that are four to six inches of desert plants because they need the minimal water.
  6. During your monthly walk through your garden roof, watch for diseases and pests. A garden roof top will attract more insects.
  7. Keep a maintenance diary and log all the details such as when you feed, water, and weed.
completed green roof

Up On The Roof Top

If a green roof sounds like something that you’re interested in, have a structural check of the building to make certain it can support the weight. Even if you’re planning on planting and maintaining the garden yourself, have a professional roofer make sure the existing membrane is in good condition and get a quote to have them install a waterproof membrane if needed. Dial 513-342-8544 for even more information about a green roof in Cincinnati, OH.