How A Sedum Roof Can Protect The Waterproof Membrane | Turf Online Knowledge Base

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How A Sedum Roof Can Protect The Waterproof Membrane

The four ways in which Green Roofs protect waterproofing

Harmful UV rays can significantly reduce the life of your roof making it susceptible to leaks. Your green roof will love the sun though and provide a layer of protection that can save you money by doubling the life of waterproofing.

There are a number of contributing factors in these results, such as:

  • Protection from human activity
  • Wind-blown debris
  • Buffering temperature extremes
  • Shielding from UV radiation

This last point, is in fact one of its more primary environmental benefits; deflecting the UV rays that would have otherwise been absorbed.

A Green Roof protects waterproofing from extreme temperatures

Your green roof provides diverse thermal qualities meaning that as a result it has a higher albedo (ie it reflects more of the sun’s energy than a conventional roof) because of its natural technology. This solar reflectance varies, depending on the number and the types of plants growing on there, although generally it is between 0.3-0.5 ̊C cooler than your conventional roof. ( Levinson, Ronnen (2010). “Cool Roofs, Cool Cities, Cool Planet” (PowerPoint Slides). Retrieved 10 December 2011.)

The heat that is absorbed by your green roof, will become trapped by the greenhouse effect, later being cooled by evapo-transpiration; the process of plants releasing moisture back into the atmosphere. In turn, this process will aid the cooling of the roof. (It’s the same process that makes a lawn into a lovely cool place to sit while a paved area will be very uncomfortable on bare skin.)

Fluctuating temperatures are bad for waterproofing

With an ever increasing presence of climate change, the rapid fluctuation in external temperatures is a common occurrence. These dramatic differences inevitably have a domino effect on the environment, especially on the buildings within it.

The temperature changes between day and night, summer and winter, can ultimately cause your waterproofing to crack. By adding a green roof build up, the temperature of the roof membrane is kept almost constant and damage is minimilised.

Protection against UV light

The barrier that your green roof provides is essential. This natural blanket will prevent your roofs membrane enduring any direct exposure to sunlight that would have previously caused it to degrade much faster. This is often a common occurrence when the roof is exposed to the elements and harmful UV rays are able to directly penetrate the structure, sequentially causing it to expand and contract throughout the day.