Gravel Grid Driveways - Installation, Stone, Sub-Base & Grid Guide
Why reinforcement matters
A gravel driveway that stays put. IBRAN grids lock the stone into cells so the surface stays level, drains freely and needs almost no maintenance once it is down.
Gravel is a genuinely good driveway surface. It drains, it looks right on almost any property, and it costs a fraction of block paving. Loose gravel fails because the stone can move. A grid doesn't replace the stone or the sub-base — it confines the finished gravel layer so the stone can transfer load without migrating.
Held in a cellular grid, each stone sits in its own cell and load spreads across the whole surface instead of concentrating under the tyre. The stone still does the structural work: the grid simply stops it going anywhere. That is the difference between a driveway you rake every spring and one you park on and forget.
Where this works well
- Domestic driveways
- Shared private drives
- Turning circles and parking bays
- Sloped approaches
- Wheelchair accessible routes
- Laying over existing concrete or tarmac
At a glance
| Sub-base | 50-80mm MOT Type 1 (100-150mm for regular van traffic) |
| Infill | 6-20mm graded blend, angular and clean, filled level plus a 5-10mm blinding |
| Typical loading | Cars, light vans and occasional delivery vehicles |
| Permeability | Fully permeable. Normally treated as a SuDS component in a drainage strategy |
| Planning | Permeable surfaces do not normally require planning permission for a front driveway in England |
| Design life | 25 years, subject to documented installation |
| Material | 100% recycled polypropylene, made in the UK |
How it goes in
- Mark out the area and excavate to the depth of your sub-base plus the grid depth plus your infill blinding.
- Lay a woven geotextile across the formation, lapping joins by at least 300mm. This keeps the sub-base and the subsoil from mixing, which is what preserves the depth you have just paid for.
- Lay and compact the sub-base: 50-80mm MOT Type 1, or 100-150mm for regular van traffic. Compact in layers rather than all at once, so the plate can do its job all the way through.
- Blind the sub-base with a thin layer of grit sand and screed it level. This is what gives you a flat finished surface.
- Push-fit the grids together across the area, working from one edge. Cut around obstacles with a jigsaw or fine-tooth saw.
- Fill the cells with a 6-20mm graded blend, level plus a 5-10mm blinding. Work the fill in with a stiff brush so no cell is left hollow.
- Check the finished level. Nothing should stand proud of the cell walls, and no cell should be left under-filled.
Most of this is straightforward groundwork. The grids themselves push-fit together and need no fixings, adhesive or specialist tools. Full step-by-step detail is in our gravel grid installation guide.
Choosing your stone
Use a graded blend of 6-20mm, angular and clean. Most guidance points you at a single size, and a single size leaves voids: uniform stone bridges against itself and never quite packs solid. A blend fills those gaps, because the smaller stone wedges in between the larger.
It is worth getting right. A fully bedded cell puts load through the stone and into the ground beneath. A part-filled cell puts it through the plastic instead. The stone should be doing the work, and a blend is what lets it.
Ask your merchant for washed graded aggregate, angular rather than rounded. Rounded pea shingle rolls underfoot however well graded it is.
Which grid depth?
The number on a grid is a decision about how deep the confined stone layer is, and that sets your excavation, your stone volume and your finished level.
IBRAN®-X30 is the right choice for most driveways. The shallowest build-up, the least excavation and the least stone, and the grid to use if you are going over existing concrete or working to a tight threshold or DPC level.
IBRAN®-X40 where the same surface also has to carry grass, or where you want additional depth without a specification calling for it.
IBRAN®-X50 where a drawing or engineer has specified a deeper confined layer, or the drive takes sustained commercial traffic.
If you are between two options, take the heavier duty one. The cost difference across a typical project is small next to the cost of lifting and relaying a surface that was under-specified.
Get it right first time
The one thing worth knowing: keep the fill level.
Anything more than about 10mm proud of the cell walls is unconfined stone, and unconfined stone behaves like loose gravel because that is exactly what it is. Fill the cells level, add a thin blinding over the top, and the surface will hold. If you ever see ruts starting in the top layer, the fill is simply too deep, and brushing it back level fixes it.
Design your surface
Set out the area, choose a grid and an infill, and see the finished surface. The schedule and the specification follow.
Permeable surface specification
Schedule
Assumptions
Specification
Common Questions
How much gravel do I need on top of the grids?
Fill the cells level and add a 5mm to 10mm blinding layer over the top. Any deeper and the stone above the grid is unconfined, which means it can still migrate.
What size gravel works best in a gravel grid?
A graded blend between 6mm and 20mm, angular and washed. Angular pieces interlock where rounded pea shingle rolls, and a blend packs tighter than a single size because the smaller stone fills the gaps between the larger.
Do I need a sub-base under a gravel driveway?
Yes but there is no single sub-base depth that suits every driveway. Ground conditions and expected loading determine the required construction depth. As a starting point, domestic driveways commonly use 50mm to 80mm of compacted MOT Type 3. For regular van or delivery traffic, go to 100mm to 150mm.
Compact it in layers rather than all at once, so the plate can work through the full depth.
Can you lay gravel grids on a slope?
Yes. Grids are particularly effective on slopes, because the cell walls stop stone washing downhill in heavy rain. A sloped gravel driveway without confinement will always migrate to the bottom of the run.
Do I need planning permission for a gravel driveway?
In England, a permeable driveway will not normally require planning permission solely because of its surface water drainage, although restrictions can apply in listed buildings, conservation areas and other circumstances. Impermeable surfaces such as concrete and tarmac usually do. Check with your local authority if your property is listed or in a conservation area. Always check with your local planning authority if you're unsure.
Check with your local authority if your property is listed or in a conservation area.
Do I need to remove my existing driveway first?
If it is loose gravel, usually not. Rake it out, compact it and check your levels.
If it is broken tarmac or concrete, it has to come up or you will have no drainage path beneath the new surface.
Do gravel grids need edging?
Use edging strips where the drive meets a lawn or border, and ramp edging at the entrance or against a threshold. The perimeter takes load that the interlocked field does not, so restraining it keeps the whole installation tight.
How long does it take to install a gravel grid driveway?
A typical two-car driveway of around 40m² is a weekend job for two people, excluding excavation and muck-away. The grids themselves push-fit together and need no fixings, adhesive or specialist tools.
What maintenance does a gravel grid driveway need?
Very little. Check levels after the first winter and brush any settled cells back up. No annual raking and no yearly top-up, because the stone is confined and has nowhere to go.
Ask our engineer
Questions about depths, sub-base, edging or which system fits your project? Ask below.
