19 Mar 2020

Rainwater and roofline systems – the sustainable alternative to plastic pollution

Every time you open a newspaper, watch the news or settle down for a wildlife documentary, we are presented with the huge issue that is ‘plastic pollution’. This is not just about plastic carrier bags and bottles; it is also about the plastic used in the construction of our own homes.


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Building your own home is fraught with issues and spiralling costs, not least the consideration of your build’s impact on the environment and what will happen to the materials once it reaches the end of its useful life. When it comes to roofline and rainwater systems, there are a few alternatives to plastic – aluminium, cast iron and galvanised steel, for example.

The case for aluminium

Aluminium is a naturally occurring, abundantly available metal. In fact, it is the third most plentiful element in the earth’s crust. Aluminium is such a versatile material – its strength-to-weight ratio makes it more desirable in rainwater systems than cast iron, because it is lighter and easier to fit than cast iron. It is an ideal material as it is non-combustible, does not rust, will not fade even after being exposed to UV light and needs very little maintenance to keep it in tip-top condition. Only a quick wash down with soapy water is needed.

Another plus; it can be polyester powder coated to virtually any RAL/BS colour so that the aesthetics suit the property and the surrounding environment. Or it can be coloured to make a statement or to match window and door frames.

Recycling and sustainability

Aluminium can be infinitely and widely recycled without loss of material properties and is easily formable into items such as gutters, downpipes, fascias and soffits.

Nearly 75% of aluminium that has been produced since 1886 is still in use today1. Plus, the energy needed to recycle aluminium is 95% less than the raw extraction process.

The recycling rate in building applications is 92-98% (Aluminium Federation), and the industry is continually looking to improve this figure, by innovating methods and processes to make recycling even more energy-efficient.

Around 50% of the electricity used to produce primary aluminium worldwide comes from environmentally-friendly hydro-electric power and other renewable, non-polluting sources.

Cost implications versus sustainability

Cost can be an important factor when considering the material choices for self-builds, and often the roofline and rainwater system is one of the last things to be budgeted for, and this is where the choice of plastic is often made, as it is readily available from builders’ merchants and often the cheapest offering available. However, when you compare the plastic lifespan in comparison with aluminium, the initial outlay can be more expensive for aluminium, but the longevity, rigidity and colour fastness is not expected to outlast aluminium.


The construction industry is a major consumer of aluminium; it is used extensively in window frames, roofing, cladding, fascias and soffits, rainwater systems as well as coping and cladding and other architectural elements which help protect the building from the elements.

Because aluminium’s strength-to-weight ratio is so low and it is so formable, it can be extruded, cast and pressed making it the perfect material for roofline and rainwater products. It can easily be formed into pipes, gutter lengths, fascias and soffits, wall copings, cappings and cladding. Being lightweight, it is comparable to fitting plastic and provides many years of protection with minimal maintenance.

So when you are specifying materials for your next project, consider the benefits of aluminium for your budget, the project and the environment.

Further information....

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