You’re absolutely right, gravel will be impractical for a drive with a slope like that. Quite apart from the constant topping up that you’d need to do, because the gravel will naturally roll downhill when someone drives over it and whenever it rains hard, there be a health and safety aspect. Shoes would sink into a thick layer of gravel, which would be more likely to stay in place on a 1:12 slope, and a thin layer would roll on the supporting bed of concrete or other hardstanding.
Both would be very tricky for people to walk on, particularly the elderly, and in some circumstances you might even have trouble getting traction in a vehicle.
However, it is quite understandable to want to avoid the ‘suburban’ look of Block Paving. The good news is that there are a couple of ideas that could work and give you the look you’re after.
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Try Small, Rounded Cobbles
First, you could try setting small cobbles into a concrete substrate, a technique that’s covered in our ‘Loose Materials’ section (see Advice on Hoggin, Cinders and Ash Driveways). If you chose small, rounded cobbles, you’d get close to the look of gravel. But the aggregate would be set in the bedding layer, so it wouldn’t be off down the hill at the first opportunity.
It can be uncomfortable to walk on though, so you might consider gravel or paving stones for the paths leading from the house to the drive. Check out our article about how gravel size matters.
The other option is to use small pieces of natural stone, such as slate. It’s expensive, but with a 1:12 slope you’d only need two or three stones per square metre around the edges of the drive to keep everything in place and give you peace of mind (the advice on our Driveways page about grading
Cellular Mats
The second option would be to look at some of the newer cellular supporting structures for drives. Again we’ve covered these on the site (see Cellular Paving Systems For Your Driveway) but focusing on their use as a material that will allow grass to grow through them. The good news is that you can use these cellular mats with the cells filled up with gravel instead of letting grass grow through them.
On a 1:12 slope, you would almost certainly still lose gravel to some extent, so occasional topping up would be necessary. This will be particularly so after a six-month bedding-in phase, as the gravel compacts in the cells. But after that it should work well. An edging course might be a good idea, as that would restrain any gravel that escapes from the cells.
If you do go for the gravel option, consider that you might need to edge your driveway with two different types of gravel. Natural uncoloured pebbles would work well with cellular matting, but coloured cobbles or stones won’t. If you do use gravel in some parts of the drive, maybe just try straight 1:
Get the Colour and Substrate Right
Choose a cellular mat that’s as close in colour as you can get to the gravel you are using, so that if it does start to poke through as the gravel compresses it won’t be so obvious.
Also talk to the supplier or manufacturer of the mat about what layers, either membranes or substrates, to put down underneath it. You’ll need to ensure that the mats will stay in place on that slope and that gravel isn’t compressed straight through into the soil below to disappear.
Make sure the gravel stays put on a 1:12 slope by using small, rounded cobbles set in concrete.
Other tips
Don’t put any paving on a 1:12 slope. Paving stones are the most slippery of all the loose materials, so you don’t want people to be walking down your drive with wet shoes or bare feet if they can avoid it.
And try to keep drains away from a 1:12 slope. A good idea for a 200mm wide driveway would be to position a drain under the centre of it, so that water heads off downhill towards either end.
But with drainage you’ll also need to think about gullies, slabs or down pipes (the pipe that carries water from your gulleys back into the soil). These should be positioned in the centre of the drive, rather than along its edges.
As you can see there are many ways to keep gravel in place on a 1:12 slope, so get creative and visit our site for more ideas.
Good luck!