CHOOSING A DRIVEWAY
Despite often being left until last during the renovation or self build process, this humble element is still an incredibly useful part of any architectural scheme. Charley Ward outlines what you need to know to get this detail right
Charley Ward sets out the key options, what you’ll pay and how to get installation right
Aproperly designed driveway performs an important role by providing a convenient, safe space to park any vehicles while giving you easy access to your property. Plus, as it is usually situated at the front of the house, it tends to have a huge impact on your home’s kerb appeal. Here, I’ve outlined the basics you need to consider to ensure you end up with a stylish, properly installed driveway that makes an attractive and well-functioning addition to your scheme.
Cost considerations
There are several main material options. Asphalt, block paving stones, gravel or resin-bound gravel (which offers a similar appearance without the potential movement issues) are all popular. These span a range of price points but overall costs will always depend on the size of the driveway and the amount of work needed for installation.
Using an existing tarmac drive as a sub-base will always be cheaper than starting from scratch. Gravel will likely be the most inexpensive up front at about £30-£60 per m2 installed, followed by asphalt at £50-£70 per m2 and around £90 per m2 for block paving. For resin-bound options, expect to pay something in the region of £60 per m2 for a drive with an existing sub-base and more like £110 per m2 for a full installation. “Price-wise, resin-bound is comparable with high quality materials such as natural stone paving, so it’s more expensive than asphalt,” says Ben Shave, commercial director at Sureset, “but it comes with a 21 year guarantee, so when you consider the life expectancy and the fact that after three or four years your nice black tarmac drive will fade to a horrible grey, the cost-effectiveness of resin is pretty good.”
For those on a budget, consider looking to your local area for materials. “If you want a gravel drive but you’ve picked a stone from the opposite end of the country, you’re going to be paying a lot for the haulage,” says Tony Keates, technical director at Core Landscape Products. “If you live in Scotland and would like to use basalt, it’s a readily available and inexpensive option. If you live in the south, however, you’ll probably end up paying £80-£90 a tonne because it just doesn't come out of the ground there.”
The installation process
This is dependent on whether you are building a brand new driveway or refreshing a tired old one. If you don’t
have an existing drive that you can use as a sub-base, there’s a lot more digging to do. “You can do this on a
DIY basis,” says Ben, “but we don’t advise inexperienced individuals take on anything bigger than 30m2. It’s going to take a lot of time and you might make a mistake, so it is more cost-effective to use an approved installer.”
A typical new driveway is formed of three layers: a 100mm-150mm sub-base, a 40mm sand bed and then the final covering (usually up to 50mm deep).
A fresh installation must therefore be excavated to 200mm-250mm below the desired finished level. Any soft spots should also be dug out so they can be filled with the sub-base to strengthen them. A weed-preventing membrane should be laid at this point, as these pesky plants can even fight their way through highly compacted materials. Doing this now can save you much grief later on.
The sub-base layer is typically formed of Type 1 granular material, which consists of crushed aggregate graded from 37.5mm down to dust. This should be compressed into the driveway zone and works to spread the load of the covering and the traffic on top to the ground below. It will also aid drainage and prevent issues with channelisation – this is where two ruts develop in the surface of the drive where a car has repeatedly travelled over the same area. Next up, a layer of grit sand on top ensures a flat, smooth surface for your choice of covering to sit on. The whole thing should be designed with a fall of between 1:60 and 1:80 in order to aid good drainage.
There are variations on these basic guidelines according to soil conditions and the type and thickness of driveway material you’re laying – so make sure to always check the manufacturer’s installation specifications. If you’re using gravel, for instance, it’s a good idea to roll out a gravel grid over the sand. “These plastic hexagonal honeycombs stabilise the material so it's suitable for disabled access,” says Tony. “You retain all the traditional security benefits of gravel as you can still hear the crunch when people walk over it, but it doesn’t shift around or begin to compact, so it won’t get any ridges and will stay looking fresh and new.”
Drainage & planning permission
While having a driveway comes with plenty of benefits, their increasing popularity has raised issues regarding the potential environmental impact. When a grassy, absorbent front garden is replaced with a hard surface, the amount of water runoff when it rains increases. Many of the older drainage systems are not designed to take this amount of water and, in severe weather, there is potential for flooding.
To stem these issues, the government introduced the sustainable drainage systems (SUDS) legislation in 2008. Under this regime, you won’t need planning permission for a new or replacement driveway provided you’re using permeable materials and the rainwater can drain naturally (or the water can be directed to a lawn, border or soakaway).
Gravel, some paving blocks and resin-bound offerings are highly porous, which means they’ll let the water pass through and go back into the ground at source. “So these options are all SUDS compliant,” says Tony. “If your setup is likely to have any runoff, however, then you have to install a drain with a means for it to cope with the additional water, which is normally a soakaway. This can be connected to a combi drain or a suitable water sewer.”
If you want a driveway that crosses the pavement or verge outside your home, the kerb will need to be dropped to road level. You’ll need to apply for planning permission for this, and then separately apply to your local authority’s highways department. Provided your scheme meets their guidelines for access and visibility, it should be approved. Bear in mind that some councils will want to undertake the work themselves, but others may only do so if they happen to be resurfacing at the time – if they do not want to do it, they will likely request you use one of their approved contractors. Be sure to gather a range of quotes to ensure that you get the best deal possible.
Creating a pleasing aesthetic
Maximising kerb appeal is a great way of ensuring your home retains its full market value, so choose materials carefully and make sure that they’ll fit in with your overall scheme. For example, if you’re renovating a cosy country cottage, you might opt for a simple paved or understated gravel finish. If you’re creating a curved, double-width approach to a large manor house, a smart resin-bound or more complex paved design might be better than tarmac for creating a wow factor finish.
Resin-bound systems use a clear binding agent to contain a colourful aggregate, allowing it to show through. “It’s a great choice because of the number of varieties available,” says Ben. “We have hundreds of different stones and glasses on offer, from Italian green and tan marbles right through to silver granites from Cornwall.”
Paving blocks come in a huge number of shades and the variety of shapes on offer mean that some stunning patterns can be created to add interest to your home’s approach. “Consider colour-coordinating with other aspects, such as pathways or swimming pools, so everything matches nicely,” says Ben. “Some of our customers mix and match aggregates, so they might have a grey path leading to a buff-coloured driveway.”