Although most roofs can last several decades, almost all roofs will need to eventually be replaced. But, the good news is that there are several options for your roof that are eco-friendly and are better for the environment. The greenhouse effect occurs when the atmosphere warms the planet’s surface. Roofs can actually add to the greenhouse effect as because reflect the sun and create heat that is reflected back into the atmosphere.

Although heat and warming cycles are a normal part of the earth’s process, we are experiencing global warming which is detrimental to our planet and its natural eco-systems. A green roof is a roof that is partially or fully covered with plants and vegetation over a waterproof membrane.  There are several reasons why you should own a green roof and these include: they can add value to your property; are good for the environment; and can reduce energy costs for your home. If you need to replace your roof or simply want to create the rooftop garden or landscaping of your dreams, here are your best roofing options.

Green roof installation

Green roofs can be classified as either intensive or extensive depending on their medium and maintenance required. Before we go into your options, it is important to note that green roofs need to have proper water proofing membranes and drainage systems. There are also certain governmental requirements depending on where you live in addition to the weather conditions of where you live such as wind, snow, and rain.

Options for green roofing

Green roofs consist of a few key components in their construction: waterproofing membranes, a root barrier, filter membrane, drainage layer, growing medium, and of course the vegetation. The various membranes offer the most choices and options for green roofs as technology has created several types to choose from.

There are several types of water proofing membranes that are optimized for different types of roofs and decks. Around the world, polyvinyl chloride otherwise known as PVC and polymer modified bituminous or MB membranes are both the most common and effective membranes because they can operate and function for as long as 30 years. PVC sheets are produced by either calendering, spread coating, or extruding, and are often reinforced with polyester and glass-fiber mats. They contain additives for flexibility and achieve other desired physical properties.

MB sheet membranes are constructed by reinforcing fabrics that act as carriers for the hot polymer-modified bitumen. MB roof membranes have multiple layers and are almost always fully adhered.

Thermoplastic olefin (TPO): TPO membranes are considered as another good option for membranes and are comprised of a blend of polypropylene and ethylene propylene polymers and are often reinforced with polyester. They contain flame retardants and UV absorbers. TPO membranes are usually white in color and can be installed fully adhered or mechanically attached.

Growing mediums: There are several different commercial options that are available to consumers that focus on optimizing the growth medium for weight, water retention and drainage, and longevity depending on its intended purpose.  A disadvantage of commercial mediums is that they often lack nutrients. However, there are also several recipes available online for those that want to do-it-yourself. Many green roof experts advocate for adding mycorrhizae and pumice for drainage to native soils.

Vegetation: The types of vegetation should be chosen based on the substrate depth required and the surrounding climate. Plants can be selected for aesthetics, drought tolerance or even storm water management.

Overall, a green roof is a great way to save on energy costs that is also good for the environment. Different options for green roofing should be chosen to meet your needs and budget. Depending on your climate, you should choose membranes, a growth medium and vegetation that is best suited for your environmental conditions. 

Elena writes for Roofing Vancouver BC. She supports sustainable roofing practices and hopes more people will do the same.

Published by Elena Tahora