Made in the UK from 100% recycled polypropylene
Made in the UK from 100% recycled polypropylene
Technical guidance
The sequence below is typical guidance, not a substitute for a project design where ground, loading or drainage is uncertain.
Establish finished levels, falls, drainage route, services, subgrade condition and load case.
Remove unsuitable material to the designed formation and install an appropriate separation geotextile where required.
Place and compact the designed free-draining aggregate in controlled layers. A 150 mm Type 1 or Type 3 layer is a common starting point, not a universal specification.
Screed a level 5–10 mm sharp-sand bedding layer where specified.
Work from a straight edge, interlock panels, stagger joints where practical and cut neatly around obstructions.
Fill cells fully with the specified gravel or grass construction, overfill as appropriate, compact carefully and keep cells covered in service.
Step by step
The six steps below expand the summary cards above, from the approved X-Grid installation guide. They assume a competent contractor with the right plant; they do not replace a project design where ground, loading or drainage is uncertain.
Confirm the finished surface levels, the falls that will move water to its outfall, the drainage route, and the position of services before any excavation. Record the subgrade condition as you find it — soft, wet or variable ground changes the design — and agree the load case: what will actually use the surface, how often, and at what weight. An hour with a level and a notebook here prevents the two most common failures: standing water and edge collapse.
Remove topsoil and unsuitable material down to the designed formation level. Do not treat any published excavation depth as a universal specification — the ground decides. On clay or other moisture-sensitive soils, work in dry conditions where possible and avoid sealing a wet formation under a new construction. Where the design calls for separation, lay the geotextile flat over the formation, lapped and detailed to the manufacturer’s instructions, so the structural fill cannot punch into the ground below.
Place the designed free-draining aggregate — commonly MOT Type 1 or Type 3 — in controlled layers, compacting each before the next. Existing published guidance uses 150 mm of compacted material as a common starting point for car and light-vehicle use; site conditions, traffic and ground govern the final depth, and heavier loads warrant engineer confirmation. The sub-base is the layer that actually carries the traffic: the grid spreads load onto it, and it is the one place where compaction effort pays for itself every year afterwards.
Screed a level 5–10 mm sharp-sand regulating layer over the compacted sub-base where specified, protecting the intended falls as you go. The bedding lets the panels sit flat without point loads on their underside — panels rocked over high spots stress the connections and show as dips in the finished surface. Keep it thin: the bedding regulates, it does not build level. Level comes from the sub-base.
Start from the straightest edge — a building line, kerb or established string line — and work outward. Interlock each panel with its neighbours through the slot-and-peg connection, and stagger the joints where practical the way brickwork bonds. Cut panels with a hand saw or angle grinder and suitable PPE, and plan the layout to avoid pieces smaller than half a panel at edges and obstructions; small offcuts are the pieces that work loose. Nine panels cover a square metre, so ordering is easy to check: area × 9, plus contingency for cuts.
Fill the cells fully with the specified construction. For gravel: clean, well-graded 10–20 mm angular aggregate, filled flush and overfilled slightly, then consolidated carefully — heavy compaction on a filled grid can bite into the cells, so use a plate matcher light enough for the finish. For grass: approved free-draining rootzone, seeded or turfed, and kept off traffic until established. Sweep surplus gravel off surrounding surfaces, check restraints and levels, and inspect after the first proper rainfall to confirm the falls shed water as designed.
Approval point
Heavy vehicles, soft or wet formation, slopes, poor drainage and unusual loading require technical review before installation.
Four situations should always stop work until the build-up has been reviewed: ground that is soft, wet or untested; regular use by HGVs, plant or intensive commercial traffic; standing water, an uncertain outfall or infiltration constraints; and slopes, retaining conditions or interfaces with building foundations. Each of these changes the design rather than the installation — a steeper sub-base, a deeper construction, a engineered drainage route — and no amount of careful panel-laying substitutes for it.
Use competent contractors, suitable PPE and task-specific risk controls. Locate services before excavation, and follow the equipment, aggregate, geotextile and edging manufacturers’ instructions.
