Last year when I was driving to a friend’s house I noticed this beautiful roof off in the distance. It had beautiful flowers and greenery growing on it… so smart.  The idea of using living materials for a roof is not a new one. Applying it to modern buildings, however, is relatively new. How is the ancient art of a living roof compatible with modern building methods? And why would anyone choose a living roof for his or her home?

The Living Roof – What Is It?

A living roof, also known as a green roof, can be constructed on an existing roof or incorporated into a new structure. It can be used on commercial or private buildings. A corrugated, aluminum sheet is placed on the roof, followed by a waterproof membrane. Some builders will then apply a sheet of foam and another waterproof membrane. Drains are incorporated into the design.

 

 

Over all of the weatherproofing layers, about 4 inches of soil is placed and various greenery is planted. Many green roof builders like to focus on native plants for their rooftop “garden.”

So what are the main advantages and disadvantages of having a living roof? Read on to find out.

Advantages of a Living Roof

* Less Reflective Heat – The sunlight and heat that are reflected off of urban buildings’ roofs can greatly increase the temperature within a city. Green roofs eliminate the reflective factor, absorbing and utilizing the sun’s light.

* Insulation – Earth is a good insulator, and having four or more inches of it on your roof will keep your building cooler in summer and warmer in winter.

* Protection – The soil and plants on a living roof protect the roof structure beneath from the elements, thus preventing the wear and tear (and the subsequent leaks) that can result from exposure to the weather.

* Wildlife – Green roofs provide wildlife habitat, especially if native species are planted. Particularly in urban areas, living roofs can act as an oasis to wildlife.

* Clean air – Plants clean the air, soaking up carbon dioxide and emitting oxygen. The air around your structure will be cleaner as a result, and the more living roofs that are planted, the cleaner the air over a wider area.

* Absorption of rainwater – This helps control storm run-off, which can cause problems when it is excessive. It can also be a source of pollution.

Disadvantages of a Living Roof

* Initial expense – Living roofs can be expensive to construct. Some of the cost can be offset, though, in the savings on heating and cooling, or if you grow your own food on the living roof.

* Maintenance – Like a garden, a living roof will need some maintenance. It might need watering during a dry spell, or fertilizer may be necessary. Choosing native plant species will reduce the amount of maintenance.

* Weight – Soil is heavy, and some roof structures cannot support it.

Living roofs are beautiful, green structures that combine the necessities of building with the beauty of a garden.