Green roofs - turning the impossible into reality
As building owners become more environmentally aware, enquiries to convert existing flat roofs into green roofs have never been higher. On face value this would seem an easy task but with modern building regulations demanding increased levels of insulation as well as practical challenges such as the heights of parapet walls and other upstand restrictions – the entire process can in reality be a lot more difficult writes Justin Pitman of Proteus Waterproofing.
Many buildings, particularly those constructed in the 50s and 60s were never designed to take green roofs. Even assuming that the deck could handle the weight of an extensive sedum roof there are still several major obstacles to overcome, but none are insurmountable.
In recent months Proteus has developed a new waterproofing system using its exclusive Cold Melt® membrane with an advanced hybrid insulation that enables a warm roof
application to be easily installed on a refurbished deck.
A green roof is laid over the top and a combination of the hybrid together with the added insulation properties of the additional soil and plantings, ensures that all current building regulations are met - and here comes the added bonus – the combined insulants are thinner than conventional boards which means that in most cases there is still at least 150 mm of upstand available to safely encapsulate the roof around the borders.
Such green roofs are usually applied in urban or built up areas where there is a high risk of disruption or annoyance from odours when the membrane is installed. The advantage of Cold Melt® is that it is odour free and totally seamless making it ideal for a green roof. It is BBA accredited to last for the lifetime of the roof structure and best of all, the membrane itself incorporates recycled material making it one of the greenest on the market.
What it does is to make available the opportunity for every building owner to actually consider a green roof application, particularly in the light of recent climate change warnings.
Every green roof is of course different and will require its own calculations to ensure the right levels of insulation are used but the answer is no longer – NO – giving every building owner the chance to do their bit for the environment.