How to Lay Artificial Grass Properly
Updated: Oct 9
To lay artificial grass you dig out the old lawn to typically 75-100mm, fix an edge around it, lay a membrane, build and compact a stone sub-base with a fine granite dust layer on top, then roll out, join and fix the grass and brush in sand. The grass itself is the quick part. Almost all the work, and almost every failure, is in the ground underneath, which is why our artificial grass installation is done by the same team that builds our driveways.
What you need before you start
For a typical back garden lawn you need:
A turf cutter (hire) or spade, and a way to get rid of the spoil
Edging: treated timber, steel, plastic lumber, sleepers or an existing paved edge
Weed membrane and galvanised U-pins
MOT Type 1 or 10-20mm granite or limestone chippings for the sub-base
Granite dust (often called grano) for the laying course
A vibrating plate compactor (hire), a rake and a straight timber screed
The grass, joining tape and outdoor adhesive, a sharp knife with spare blades
Galvanised nails or U-pins for the edges, kiln-dried sand and a stiff brush
The spoil catches people out. Digging out 75mm over a 40 square metre lawn produces about three cubic metres of soil and turf, which is a skip or several trips to the tip.
Step by step
Dig out. Remove the turf and soil to typically 75-100mm below where you want the finished grass (deeper on clay or wet ground), down to firm ground. Take out roots and large stones.
Fix the edges. Set the edging so it sits just below the finished grass height. Timber is usually set in concrete or staked; steel can follow curves. Without an edge the sub-base slowly spreads and the perimeter sinks.
Lay the first membrane. A weed membrane goes on the dug-out soil, overlapped at joins and pinned. This stops weeds coming up from below and stops the stone pushing into the soil.
Build the sub-base. Spread typically 50-75mm of MOT Type 1 or 10-20mm chippings, rake it level and compact it with the plate. Use chippings rather than Type 1 where drainage is poor or dogs will use the lawn, because they let water through faster.
Add the laying course. Spread around 15-25mm of granite dust, screed it level to the edging, lightly dampen it and compact it several times. Every pass reduces the air in it and the chance of dips later.
Optional second membrane. Some installers add one on the dust. Leave it out if you have pets, because it can hold urine and smell.
Roll out the grass. Lay it with the pile all pointing the same way, ideally towards the house. Let it settle flat in the sun for a few hours before cutting.
Join the rolls. Fold back the edges, trim off three stitches from each so the tufts line up, leave a 1-2mm gap, then glue the edges down onto joining tape. Leave the adhesive to cure (anything from 2 to 24 hours depending on the weather).
Cut and fix the perimeter. Trim tight to the edging and nail into timber or pin into the ground for steel, sleepers or paving.
Infill and brush. Spread kiln-dried sand at typically 4-6kg per square metre (depending on pile height) and brush it in against the pile with a stiff brush to stand the fibres up.
Weather mostly affects the dig-out and how long the join adhesive takes to cure, which is why the best time of year to install artificial grass has more to do with ground conditions than the season.
Can you lay artificial grass on grass?
Not if you want it to last. Laying artificial grass straight on top of a real lawn traps the old grass underneath, where it dies and rots. The surface goes lumpy within a season or two, water sits in the decaying layer, and weeds come up through the drainage holes. The old turf has to come out and a stone base has to go in.
Where DIY artificial grass goes wrong
Lawns that fail within a year or two of being laid nearly always share the same faults:
Not dug deep enough. Grass laid on a thin bed of sand over soil moves, dips and holds water.
Sharp sand instead of granite dust. Sand shifts underfoot in summer and forms lumps when wet. Compacted granite dust stays put.
Under-compacted base. One pass with the plate is not enough. Dips show up wherever someone walks most.
No proper edge. The perimeter is where a lawn fails first: edges lift, curl or sink as the base spreads.
Visible joins. Pile running different ways, or rolls butted without trimming the stitches, shows as a line or a colour change.
Clay with no drainage plan. The stone base holds water but cannot get rid of it if the ground below is solid clay and there is nowhere for it to go.
The grass is the expensive part to replace, so fixing a bad base usually means lifting it, rebuilding the ground and relaying.
When to get it fitted
Small, flat, square lawns with good drainage are a fair DIY project if you hire the right kit. Big lawns, slopes, clay soil, curves, lawns meeting a patio or path, or anything used by dogs are where a fitted job pays for itself. For dog owners in particular, see artificial grass for dogs, because the base needs to be built for drainage first.
Dig-out, sub-base and compaction are the part of the job we know best. If you are also replacing a path, a firm hard path gives a clean edge for the grass to run up to.
Artificial grass laying questions, answered
How long does it take to lay artificial grass?
The ground preparation takes most of the time. How long depends on the size, the access and how much has to be dug out and barrowed by hand; laying and joining the grass is the quick part.
Do you need sand on artificial grass?
Most domestic grasses are designed to take kiln-dried sand infill. It weighs the grass down, helps the fibres stand up and protects the backing. Check what the manufacturer says for your grass.
How long does it last?
With a proper base and regular brushing, artificial grass typically lasts 15-20 years or more. A poor base shortens that far more than the grass quality does.
If you want a lawn laid properly in Wolverhampton or the West Midlands, Pete and the team will look at the ground, the drainage and the edges on a free site visit and give you a free quote.
