There are many areas of construction work in which the need for sustainability is now being prioritised but not many people will be aware that there is currently a drive for greater sustainability in the construction of roads, car parks, walkways and pavements. The incentive is known as Sustainable Urban Drainage Systems (SUDS) and the motivation behind it is to achieve a local control of rain water – at its very source – rather than at a treatment centre in some other location. An increasingly popular way of meeting this sustainability goal is by the use of permeable paving solutions in the construction and renewal of paved areas. In this article we describe exactly what constitutes a permeable paving solution and set out the two principal types of permeable paving. We also look at some of the maintenance procedures that are necessary to ensure that the system remains functional for as long as possible.
What Is Permeable Paving
Permeable paving means, in simple terms, a paving system through which water is capable of passing. Instead of surface water accumulating, as it will do when it hits a non-permeable surface like concrete, the water is allowed to drain through the paving stones. This has the result of reducing the already substantial pressure that our sewage and drainage systems are under. It also limits the number of pollutants that drain into our water treatment plants and our water courses.
The permeable pavement solution is therefore one that complies closely with the aim of SUDS in a manner that the traditional non-permeable surfaces, such as concrete are incapable of doing. This is a real advantage, as more and more of our surfaces are being paved.
Permeable paving is a great alternative to using concrete paving
Types of Permeable Paving
There are two main types of permeable paving: infiltration and porous.
Infiltration Permeable Paving
This type of permeable paving solution consists of a construction of paving blocks, which have gaps or voids between them. This system permits the drainage of all rain water allows all rainwater that affects the pavement to flow through, or infiltrate those gaps or voids. The water then drains between the solid structures of the pavement blocks onto the sub-surface below them.
Porous Permeable Paving
The word porous means “consisting of pores” and this is the basis of the second type of permeable paving. In the porous permeable paving system, the water drains directly through the material, rather than between the gaps in individual paving blocks. Gravel based some types of asphalt and turf paving systems are particularly suitable for porous permeable paving.
Regular maintenance is important to keep the paving up to shape.
To ensure that a permeable paving system has as long a life as possible it is necessary to carry out regular maintenance work. If the pavement becomes blocked it will lose its effectiveness and act like non-permeable material. In porous systems there is a tendency for pieces of grit or dirt to become stuck in the pores. To avoid this, it is necessary to use industrial vacuum cleaners, jet washers or brushes to clear them regularly. For infiltration paving, jet washing may also be necessary to remove any debris that has become stuck in the gaps or voids between the paving blocks.
Whilst improvements in technology are likely to reduce the time and money spent on maintenance, it remains a significant issue for private and public landowners alike.
In order to meet the increasing emphasis on the aim to make the planet more sustainable, the need to lessen the pressure on our sewage and drainage systems and to reduce the impact that pollutants have on our water courses, an alternative to the traditional concrete pavement had to be found.
In those respects, permeable paving solutions certainly do represent a viable alternative to concrete and other less eco-friendly materials.