Specifier Review
Green Roofs

Riefa Lightweight Living roofs

ONE of the paradoxes of the living roof industry is that, for all our evangelical promotion of the environmental agenda, our products have often been surprisingly un-green.

Living roofs are a case in point. What we hold out as the bright new hope of the inner city frequently requires an onerous quantity of plastic trays, felt bases, and granular linings whose eco-credentials are, to put it kindly, borderline.

Ten years ago, I was introduced to a product which, the German makers claimed, would change that. I was initially dubious about the whole proposition; how was this vorsprung durch organic product going to live up to the remarkable promises made?

A decade on, I am utterly convinced. And I’d like to take the next couple of minutes to explain why, and urge you to test the truth of the Riefa system for yourselves.

living roof

Riefa boards are a new type of green roof substrate.  They are a hi-tech fibre board made from organically grown and sustainable natural resources, including rye flour and tree bark. There are some other ingredients in there too, but forgive me if, for reasons of commercial confidence, I don’t expand on them here. But rest assured they are innovative and do what the designer intends.

The image above shows the Riefa® Board prototype green roof that was planted over ten years ago. As you can see the roof still looks beautiful after a decade.
The image above shows the Riefa® Board prototype green roof that was planted over ten years ago. As you can see the roof still looks beautiful after a decade.

The manufacturing process is essentially the same as baking: the ingredients are mixed in dough bins and then baked in second- life biscuit ovens. A case, I hope you’ll agree, of a virtuous circle in both production and procurement.

Riefa boards are primarily used as an insulation board in the manufacture of doors and as a sound insulation in partition walls. The dimensions of the boards in their dry condition are 18mm thick and 2400 x 1200 mm, and they only weigh 1kg. This makes them very easy to transport and distribute across the roof, both important considerations when setting out a method statement to potential clients.

So who needs another living roof product? After all, everyone in the industry knows about the various green, brown and bio-diverse roofing systems on the market.

A living roof basically turns a roof into a bund to control the flow of rainwater and provide a bio diverse habitat.

However, the blunt truth is that the eco-credentials of many of these systems are flawed.  The majority of living roof products rely upon plastic trays, aggressively dried granular mediums, drainage layers, filter fleeces, and a felt roofing base.

It defies logic and any kind of genuine environmental concern that, for years, we have been championing well-intentioned green roofing systems that are so heavily carbon based they rely upon a reinforced roof and wall structure simply to hold them up. It puts you in mind of the philosophical question: “Can an all-powerful force create a weight so heavy, that the creator cannot lift it?”

Living and bio-diverse roofs have too important a contribution to make towards urban greening and rain water attenuation to become undermined by the shallow promises of implausible designer products. We need them to work sustainably and holistically; they are not some cosmetic garnish to be scattered on a corporation’s green policies.

The Riefa organic fibre roof-growing medium is the response to a pressingly real requirement.  Made and produced from in a demonstrably sustainable way, it is the lightest product in the world which fits neatly into place, its low depth profile doing away with the need for expensive alterations to parapets. Easily installed over tired or redundant roof covers, a simple rubber membrane overlay eliminates the need for expensive removal and removes the need for the disposal of hazardous oil-based systems.

As a contractor, you do not need specialist skills to install the Riefa system. It fits seamlessly onto sloping, pitched or shaped roofs of all kinds. Nutrient rich and superb at retaining water, Riefa boards have been tested to destruction as a growing medium.Living Roof

Being evangelical about the environmental does not mean becoming a pious eco-bore. We all want comfortable places to live and work.  However, there is now no sensible rebuttal to the argument that we have to temper the amount of energy we burn, and I’d go further and suggest our industry should set an example to the developing world of how to achieve that in a practical, low tech and affordable way.

Our stressed infrastructure simply cannot take any more run-off. Our cities are becoming too hot, our demands for comfort cooling too great. Living roofs will unquestionably need to be part of the new urban landscape, and Riefa is leading the way in making that a reality.


Green Roof