Porous Pavement Pros And Cons: The Ultimate Guide
The first thing you are probably asking is “what on earth is porous pavement?”. We promise that question will be answered shortly.
One thing we can say is that porous pavements, patios or driveways are the perfect way to prevent the damage that can be caused by water and ice and they protect the environment as well.
Clearly porous pavements are important, but are they always necessary, and what if you prefer a non-porous material? We have the answers, and we’re here to share them with you in the following article…
What Is Porous Pavement?
Also known as permeable, a porous pavement is simply a material that allows the free drainage of water through its surface and into the ground beneath.
In most cases, and up until recently, a porous pavement choice has been limited to asphalt and concrete, but now that category has extended to resin bound driveways and paths as well.
The main reason these materials are porous is to do with how they are produced. All three involve the use of stones, crushed rock and other aggregate materials that are bound together with a binder.
The larger the aggregate, the more porous the surface will be. In the case of concrete, the binder is cement, bitumen for asphalt, and resin for resin bound. This mixture provides larger gaps between the aggregates, to allow the flow of water, and yet it is bound together due to the binder.
When it rains, water will make its way between the stones, and into the earth below, where it is simply soaked up in the same way as it is when rain falls onto a lawn surface. This is the way that the earth is designed, and will prevent subsidence that can cause problems with your foundations.
Non-porous materials that are used on pavements and driveways include: paving stones and some bricks, some types of concrete and slabs. These often allow the water to seep between the pavers, but this is usually not enough to prevent the build-up of water.
Porous Pavement: The Pros
● Environmentally friendly – the lack of run-off from your pavement or driveway means that possibly polluted water cannot make its way into the stormwater system. Water is also filtered as it passes through the pavement and the soil, making it even cleaner. In the UK, there is real risk of urban flooding and ensuring that water makes its way into the soil is a priority – for this reason, there is a legal requirement to use permeable driveway material for any driveway of more than 5 metres square. Any driveway made from non-porous material and more than this size will need planning permission.
● Lower costs – your driveway or pavement will not need additional drainage channels to move water from the surface to lawned areas. This will cut down the time needed to build your driveway. In many cases, these materials can be used quickly.
● Less standing water – your driveway will be free of puddles that can cause all kinds of problems. As this water freezes, it will cause a slip hazard, but more importantly, it can affect your pavement by causing algae to form, and if it seeps into minor cracks, it can lead to larger cracks, due to the freeze and thaw cycle.
● Sub-base protection – water that seeps under your driveway or pavement in certain areas can cause damage to the sub-base. This erosion can cause cracks in the areas above, but also issues with subsidence that can affect surrounding buildings. It is far better to have water penetration spread across a larger area than focused on smaller areas.
● Cooler – it is a little known fact that permeable pavements and driveways are cooler to stand on than non-porous materials. The areas is often absorbing water that cools it down.
Porous Pavement: The Cons
● More expensive – in many cases a porous pavement may be more expensive to install, as it needs a specialist team using specialised equipment. The raw materials may also be more expensive – in particular, the binders. The preparation of the sub-base can also be a large part of the expense.
● Maintenance – while maintaining your pavement is relatively easy, it is worth noting that the spaces between the stones can become clogged over time. A jet wash should be all that is needed to ensure the permeability is maintained.
● Weaker – it is true that a porous material may be weaker than non-porous options, however, most last upwards of 15 years, so the shelf life is still impressive.
● Soil issues – if your soil is already saturated, or is made up of clay that does not drain well, the use of a porous material may not make all that much difference. You may find that you still have to install more drainage. However, a good layer of crushed stone may help.
● Inexperienced contractors – while these materials have been used for a long time, many driveway contractors are still unfamiliar with the technical detail. This means that you may find they install the driveway without using the correct sub-bases, and that your choice of porous material is a bit pointless. Always search for the best and most experienced contractor you can.
When it comes to water, resin bound material really does come into its own. Water will not pool on its surface and simple sinks through it. The base is usually constructed using compacted soil, crushed rock and sometimes a weed barrier
Resin Bound Surfacing: A Permeable Alternative To Paving
In recent years, a new material has started to be used in pavements, driveways-and even on some roads. This is resin bound surfacing, and is created by combining resin with aggregate. It can be produced in almost any colour, using any stone that is required.
The result is a strong material that can be trowelled onto a prepared concrete base (also permeable). This surface is non-slip, not prone to ice or frost, and is easy to care for. It also lasts for around 20 years, making it one of the longest lasting driveway materials.
When it comes to water, resin bound material really does come into its own. Water will not pool on its surface and simple sinks through it. The base is usually constructed using compacted soil, crushed rock and sometimes a weed barrier.
These are covered with a concrete or tarmac base that allows water to pass through. This all means that the driveway is cleaner, less prone to cracking, and easy to care for as well.
When it comes to creating a pavement that is environmentally friendly and great looking, you really cannot do much better than resin bound and with its use becoming more and more popular, you won’t be the only one. Request your free site survey today, by calling 0800 1700 636, or by clicking the button below!