Start with the lie of the land

Gravel gets a bad reputation for puddles, and it is nearly always the preparation rather than the stone that is at fault. Before you order a single tonne, spend half an hour watching where water actually goes in heavy rain. Walk the site in wellies, note the low spots, and dig a small test hole to see what you are working with — sandy loam drains freely, heavy clay holds water like a bathtub and will need more thought.

Water must have an exit. Aim for a fall of roughly 1:60 to 1:80 across the drive, which is about 25mm over every 1.5 metres. That is gentle enough to walk on comfortably but steep enough to move surface water. The fall should always run away from the house, garage or shed, never towards them. If the ground is stubbornly level, create the slope artificially with your sub-base rather than hoping for the best. On a sloping site, consider a shallow channel or French drain at the bottom to catch what arrives.

Excavate to the right depth

Depth is where most DIY drives go wrong. For a pedestrian path or a lightly used parking area, allow 150mm of build-up. For a driveway taking cars, work on 250–300mm. A sensible breakdown is 100mm of compacted sub-base for foot traffic or 150mm for vehicles, then 40–50mm of gravel on top.

• Strip topsoil completely — it compresses, moves and grows weeds.
• Keep the best of it for borders; it is far too good to skip.
• Excavate a little wider than the finished drive so edging has something solid to sit against.
• Firm the exposed ground before you start building up again.

Build a sub-base that will not sink

The sub-base is the backbone of the whole job. Use MOT Type 1 for a bound, hard-wearing base, or Type 3 if you want an open-graded material that lets water pass through more readily. Type 3 is the better choice where drainage is your priority, though it needs confining edges to stop it spreading.

Lay it in layers of no more than 75–100mm and compact each one properly. A plate compactor is fine for small areas; hire a vibrating roller for anything larger than a couple of car lengths. Dampen the surface lightly as you go — it helps the fines bind — and work in two directions, at right angles, over each layer. The test is simple: press your heel in hard. If it leaves a dent, keep going. A properly compacted base should ring slightly underfoot and refuse to move.

Membranes: the right one, in the right place

Two different problems get muddled together here. The first is stones sinking into soft ground; the second is water failing to drain. A geotextile membrane — woven or non-woven, around 100–150gsm — laid over the compacted sub-base and under the gravel solves the first. It stops fine particles migrating upwards and stops your expensive stone disappearing downwards.

What you must not do is lay heavy plastic sheeting. It looks like a bargain and behaves like a paddling pool, trapping water directly beneath your gravel. Equally, do not wrap the sub-base itself in plastic. Water needs to move down and sideways, not sit in a sealed tray. On heavy clay, a permeable cellular grid filled with gravel is often the most reliable answer, as it holds the stone in place and keeps the structure open.

Pick the right stone, to the right depth

For a driveway, 14–20mm rounded, washed gravel is the sweet spot. Washed means no dusty fines, and no fines means water runs straight through instead of forming a sticky, impermeable crust. Rounded stones roll and settle into an even surface rather than locking into a rigid mat, so they shed water beautifully and are kind to tyres, paws and bare feet.

Angular chippings bind together into a hard surface, which sounds appealing, but that crust tends to crack, rut and hold puddles in every dip. Avoid limestone near doors as it tracks indoors, and avoid anything below 10mm, which scatters and clings to shoes.

Spread the gravel to 40–50mm — enough to cover the membrane and look generous, but rarely more. Deeper gravel is exhausting to walk on, ruts under wheels and buries the membrane that is doing the work. Rake it level, then settle it with a light pass of the compactor or a few trips with the car.

Edging, topping up and the habits that keep it draining

Gravel has no natural edge, so give it one. Treated timber sleepers, steel edging, block paving setts or granite kerbs all work well provided they are set below the finished surface — leave the gravel about 25mm proud of nothing and 25mm below the top of the edging. That lip stops stones migrating onto the lawn and keeps the profile intact.

• Rake the surface twice a year to redistribute stone and close up ruts.
• Top up by 10–15mm annually; a thin, even layer beats a thick dump in one spot.
• Clear fallen leaves promptly — they clog the surface and turn to compost.
• Pull weeds when small rather than spraying, and avoid pressure washing, which blasts fines into the voids.
• Vary where you park if you can, and keep heavy vehicles off the edges.

Do these small things consistently and a well-built gravel drive will drain freely for a decade or more, looking better each year rather than worse.