BUYERS’ GUIDE
Geoff Hodge looks at how to choose sustainable paving products
We’re all quite rightly being encouraged to “go green” or “go greener”, reducing our household inputs and waste, using green power sources, installing heat pumps and solar panels and the like. But we should also consider and rethink our inputs into our gardens – and more than reducing or eliminating pesticides, going peat free, not using petrol-powered machinery and concentrating on drought-resistant plants to reduce how much water we liberally splash around the garden.
One area that we should be considering is our choice of hard landscaping materials and their impact on the environment, and in particular our paving choices for paths, patios and hard standing areas.
Probably the worst offenders are concrete-based paving products. Most concrete paving, also sold as reconstituted stone, uses cement to bind the aggregates and sand. Cement production is one of the most energy-intensive manufacturing processes, which also gives off a cocktail of air pollutants including dioxins, dust and hydrocarbons. After water, concrete is the most widely used substance on the planet! Taking into account all stages of production, concrete is thought to be responsible for 4-8% of the world’s CO2 emissions, although apparently this is 1.5% in the UK due to our better production processes. It also sucks up almost 10% of the world’s industrial water use. Among materials, only coal, oil and gas are a greater source of greenhouse gases.
Around 900g of CO2 are emitted in the production of 1kg of cement, although some is reabsorbed when concrete is exposed to air, bricks add 250g/kg and 1sq m of stone patio adds around 47.5kg of CO2, but this does depend on the stone.
ON THE MARKET PAVING SLABS
There are currently a few concrete paving products that are more eco-friendly than others. The carbon footprint of Bradstone’s ECO range, for instance, has been reduced by more than 20% and ECO Evolve by 35% compared to its similar products. This has been achieved by making improvements in manufacturing and the mix used. Deco-Pak’s Eco Smooth Paving has 85% of its content derived from sustainable resources and 87% of its material is sourced within 45 miles of production.
