Gravel drives and paths continue to be a popular choice, especially for larger areas where the cost is considerably cheaper when compared to a paved or hard surfaced driveway. The installation of a gravel driveway is relatively straightforward, and well within the ability of a home DIYer if you have the time.
What are the advantages of a gravel driveway?
In addition to lower material and installation costs than a paved driveway, a gravel driveway has several other benefits:
- no need for additional drainage
- no need for planning permission because it is a permeable surface
- very low maintenance- occasional raking is all that is required
Which gravel should I use for a driveway or path?
For most decorative applications the choice of aggregate or gravel is purely a question of colour, texture and size, however for paths or driveways there are a few more considerations.
For driveways it is best to select hard, angular gravels between 14 and 20mm in size, such as Long Rake Spar Polar White. Angular stones knit together to form a firm, stable base for vehicles, and chippings above 14mm in size won't get stuck in tyre treads. However, stones above 20mm in size will increase the wear on tyres.
For pathways choose an angular stone of between 10 and 20mm such as Long Rake Spar Black Ice or Cotswold Chippings. Angular stones are much easier to walk on than rounded stones, and stones above 10mm in size won't get caught in shoe treads.
What are the basic steps for laying a gravel driveway or path?
- Dig a foundation
- Add a layer of weed suppressing membrane
- Add your edging
- Add a sub-base
- Add your gravel grids and decorative gravel
What are gravel grids?
Gravel grids are plastic, honeycomb-like sheets that are laid on top of the sub-base layer to stabilise the gravel layer. These are recommended for gravel driveways (especially if on a slope) because of the force that vehicles exert on the gravel, but are also used for gravel pathways where a stable surface is required.
Pieces of gravel sink into the individual cells of the grid, forming a framework to stabilise the upper layer of gravel and preventing ruts or shifting.
A common problem with open gravel grids is that they will rise up over time in the gravel layer, becoming exposed at the surface. Our CORE DRIVE gravel grids have a membrane heat welded to the base of the grid, meaning that the gravel cannot pass through over time, and the grid will remain in position.
Because the membrane is integrated into the grid it also means that a separate weed suppressant membrane does not have to be laid in the driveway foundation.
1. Dig a driveway foundation
A steady foundation is essential for any driveway to support the regular movement and weight of vehicles. Once you have measured the driveway area, dig a foundation of at least 200mm - this will allow for a 150mm sub-base and a 50mm layer of gravel.
This job can be done by hand, but you may wish to hire a mini mechanical digger for the day. If you do not have extra room to redistribute the excavated earth you will also need to hire a mini skip to have the spoil removed.
2. Add a layer of weed suppressing membrane
Line the foundation with a layer of heavy duty weed membrane. In addition to preventing weed growth, this permeable membrane will allow rainwater to freely drain through, and will also prevent the sub-base layer from settling into the soil over time.
3. Driveway edging materials
A gravel driveway will need some sort of edging to keep the gravel contained if bordered by flowerbeds or lawn. A popular method is to use driveway block pavers or bricks which can be set in a 100mm layer of post-mix concrete. Place the edging stones on the foundation and lightly hammer into place with a rubber mallet, using a spirit level to check for an even level along the length of your edging. This will set the height of your final gravel surface.
Then secure the stones in place by spreading concrete up the outside surface of the stones (haunching) to around halfway up the stone's height.
An increasingly popular way to edge straight driveways is to use railway sleepers. Because of their weight it's not essential to concrete them in, so if a taller edging is required these can be laid directly onto the sub-base once laid, rather than on the foundation.
Alternatively, try steel edging - this can provide a quick and sturdy edging for gravelled areas, and doesn't need concreting in.
4. Lay a driveway sub-base
The sub-base is the layer of your foundation that provides stability to the structure, and prevents the gravel layer from simply sinking into the ground over time. Lay a 75mm layer of MOT Type 1 hardcore then level and compact with a wacker plate, which can be hired for the day. Add another 75mm layer and repeat the compacting a further six times to ensure you are left with a fully stable base.
5. Add your gravel grids and decorative gravel
Lay your gravel grids if you're using them, then add a 50mm layer of gravel and rake over the surface to level. Finally, hose down the gravel to remove any dust and your driveway is ready to use.
How much gravel or stone chippings will I need?
It's difficult to be exact when estimating the quantity of slate or stone chippings required for a project as different shapes and sizes of stone will settle at different depths once laid.
However as a general rule a bulk bag of decorative aggregate (approx 600kg) will cover an area of approximately 7.5m2 at a depth of 50mm.
How to lay a gravel pathway
The instructions above are for a driveway, but the method for laying a gravel path is the same but with a shallower foundation - a 100mm deep foundation, 50mm sub-base and 50mm of gravel. Because the sub-base is shallower you can compact it with your feet, rather than with a wacker plate.
Top tip - if laying out a curved pathway, a hosepipe makes an ideal guide for creating long, even curves
Can I lay a gravel driveway on concrete or tarmac?
If a hard surface such as concrete or tarmac is beginning to look worn it can be tempting to simply cover the surface in gravel. This is a bad idea, and a gravel driveway should always be laid on a dedicated foundation. When gravel is laid onto a smooth surface it has no grip from below to stabilise it, and will therefore be difficult to walk on, even becoming slippery.
Because the gravel layer cannot knit together it will shift and become uneven, revealing the surface underneath. Adding more gravel to hide the problem then makes the situation worse - the gravel will be even harder to walk on, and the unstable layer will damage parked car tyres.
Ask the experts
For further advice about your garden path or driveway project don’t hesitate to speak to our friendly and knowledgeable experts at your local AVS Fencing & Landscaping Supplies branch. Our ranges of decorative gravel and building materials are available from stock subject to availability, click and collect from your local AVS Branch or home delivery within our AVS Branch delivery area.
