Homeowners wanting to upgrade or install a new driveway or other paved area in a front garden should now consider permeable paving or other sustainable drainage solutions. Delve into the pros and cons of permeable paving and the UK’s legislation requirements for more eco-friendly designs.
What is permeable paving?
Permeable paving is an environmentally friendly patio option that allows rainwater to soak into the ground below, helping to top-up the water table and reduce the risk of flooding in your local area.
Flooding is on the increase here in the UK. Rain showers are more frequent and more intense. Permeable paving reduces the amount of water flowing directly into sewers and other drainage channels during periods of high rainfall.
Driveway legislation is already in place that requires homeowners to gain planning permission for hardscape projects. This applies when paving over porous ground of more than five square metres at the front of a house.
By using permeable paving and/or other sustainable drainage solutions (otherwise known as SUDS), you may be able to bypass gaining these permissions.
But there are other benefits to permeable paving that make it a viable option for all types of gardens. Read on for the things to consider before deciding on whether your next patio project will be permeable or not.
Pros of permeable paving
There are more benefits to permeable paving than purely to bypass needing to apply for planning permission from your local council (or avoiding costly changes if you don’t). Take a look at the main plus points of permeable designs:
Reducing flood risk & topping up water table
One of the biggest benefits of permeable paving, and the main reason it was invented in the first place, is its ability to reduce stormwater runoff.
Unlike standard non-porous paving, permeable paving allows rainwater to infiltrate into the ground below. As such, it reduces the risk of puddling on patio surfaces and allows water to soak naturally into the ground.
Drainage systems in many areas of the UK can become overwhelmed during periods of high rainfall. By choosing permeable paving homeowners can do their bit to limit the runoff from their property and replenish groundwater levels.
Less heat absorbed in urban areas
During hot summer months, solid natural stone and concrete pavers can create what are called ‘heat islands’ in urban areas. These islands absorb the heat of the day making hot weather all the more unbearable.
By their very nature, permeable surfaces, such as permeable block pavers or resin-bound paving, tend to absorb less heat when compared with solid pavements.
Better for wildlife and ecosystems
Another reason why porous paving solutions are good for the environment is they help to filter out pollutants and contaminants as the stormwater passes through the surface and the underlying layers.
This filtration process can remove sediment, oil and chemicals, leading to improved water quality and reduced impact on our local wildlife and ecosystems.
New landscaping options
Rather than being a limitation on garden landscaping, permeable paving introduces new ideas to incorporate into hardscape projects that are better for the environment.
Extra greenery or vegetation can be built into the design of a project to act as a drainage area for stormwater. Even attractive seedlings can be chosen to colonise paving joints, rather than leaving the space free for the usual offending weeds.
Likewise, permeable paving can be easily combined with rain gardens or soakaways to create features that are both visually appealing and environmentally friendly.
Considerations for permeable paving
Before taking the leap and deciding on permeable paving, there are a few things to consider.
Does the soil drain well?
Permeable paving is most effective when installed over well-draining soils. If your soil has a high clay content or is well compacted, it may not offer the drainage you need.
Conduct a soil assessment to determine if your soil conditions are suitable for permeable paving. If the soil isn’t suitable, you may need to consider other options such as diverting stormwater to a more suitable soakaway.
Consider maintenance requirements
Permeable paving may require maintenance every now and then to ensure its effectiveness.
For porous stones and slabs, this may include periodic cleaning of clogged-up pores and removing debris or sediment.
Depending on the materials used, occasional resealing or regrading may also be necessary – as is the case for many other paving materials.
Sealants such as Paving Guard surface sealant can be used to protect surfaces from staining. This product is also a sand stabiliser that bonds particles of jointing sand together to prevent damage and ‘wash out’ during cleaning.
Materials and installation can be more expensive
When compared with traditional paving materials, permeable paving may have higher upfront costs. There may be specialised requirements for installation so it’s important to be aware of what you are buying.
Simple permeable paving solutions can cost the same or less than traditional paving products. For instance, using permeable brush-in grouts like PremJoint, PolySweep or ProJoint Fusion on top of a permeable bedding layer such as Perma-Bed is still comparative in cost to other paving solutions.
Always consider the long-term cost savings of choosing permeable paving. For example, will a permeable project reduce any ongoing stormwater management costs, local drainage fees or water utility bills?
Is permeable paving right for my patio?
Most front garden paving projects in the UK will require permeable paving or features built into the design to divert rainwater run-off. But what about your back garden?
Deciding whether permeable paving is right for your patio project depends on few factors:
Is rainfall or drainage a problem?
If your local area often experiences flooding – whether that be through overflowing drainage systems or rivers that are unable to cope – permeable paving can be an excellent choice to do your bit towards helping to manage this stormwater more effectively.
Are you keen to prioritise the environment?
Eco-friendly designs have certainly become all the rage, and for good reason. With permeable paving, or other sustainable drainage solutions, you will be helping to reduce the environmental impact of your project and your home.
If you are working on a property to sell-on, your new permeable patio could be a great selling point for prospective buyers who are environmentally conscious.
What are the site’s soil conditions?
On rare occasions, permeable paving may not be suitable for sites with clay soil or poor drainage capacity. Consult with a landscaping professional for insight into the soil conditions on your property.
A full range for permeable paving that lasts
If you are looking for a full permeable system, one of our most popular is the Ultrascape Permeable range from the team at Instarmac.
Instarmac’s range of permeable paving products comprises of:
#1 Perma-bed Bedding Mortar
UltraScape Perma-bed has been formulated to drain away water from cracks and joints between paving slabs which if left, can freeze, expand and dislodge paving slabs.
Perma-bed also reduces the risk of reflective staining appearing on the surface of paving slabs, which can migrate from the underside the paving elements.
Perma-bed exceeds BS 7533 and is proven to provide a perfect base for natural stone, cobbles, concrete paving, flags and block paving.
#2 Prem-Prime slurry primer
UltraScape Prem-Prime is a cement-based paving primer. When applied to the back of paving slabs, this paving primer provides an exceptional bond between all types of stone surfaces and the bedding layer.
Using Prem-Prime reduces the risk of staining and efflorescence developing on pavers.
#3 PremJoint permeable brush-in grout
UltraScape’s PremJoint Brush in Grout is a high specification, long-lasting brush-in paving compound that can be applied either wet or dry.
As a superior permeable jointing compound, the grout fills joint widths of between 5mm and 20mm and can be used in all weathers.
PremJoint is available in three grout colours: Cosmic Black, Storm Grey and Natural Cashmere.
If you’d like to find out more about permeable paving options, get in touch with our team of experts on 0330 122 1025.
