Artificial Grass: What Needs to Happen Before Installation?

Why Preparation Matters More Than the Turf

Artificial grass is often marketed on the product itself — pile height, colour, durability — but a genuinely large share of how it performs over time comes down to what’s underneath it. Poor drainage, inadequate sub-base compaction or an uneven excavation will show up as pooling water, an uneven surface, or premature wear regardless of how good the turf product is. The groundwork is where the real, lasting difference gets made.

Removing Existing Lawn and Topsoil

Preparation starts with removing the existing lawn, topsoil and any organic material from the area — organic matter left underneath artificial grass can decompose over time, leading to settling and an uneven surface later on. This is excavation and green waste removal work, not something that can be skipped by simply laying turf over existing grass.

Excavation Depth and Levels

The area is excavated to a depth that allows for the sub-base layer and drainage provisions beneath the finished turf level, with the excavated levels graded to support proper drainage rather than left flat or, worse, sloping toward the house. Getting this excavation stage right is what makes the rest of the installation possible — see our soil removal service for how excavated material and topsoil are typically handled.

Drainage Underneath Artificial Grass

Unlike natural lawn, artificial grass doesn’t allow water to soak into soil the same way, which makes drainage planning genuinely important — water needs a clear path to move through the sub-base and away from the area rather than pooling on or under the surface. See our drainage principles guide for how this same logic applies across hard and synthetic surfaces generally.

The Compacted Sub-Base

A compacted sub-base — typically a crushed rock or aggregate material — is laid and compacted to provide a firm, stable, free-draining foundation for the turf. Inadequate compaction here is one of the most common reasons artificial grass develops soft spots, unevenness or drainage problems within the first few years, well before the turf product itself would normally need replacing.

Edging and Containment

Proper edging around the perimeter keeps the sub-base material contained and gives the turf a clean, secure finish along garden beds, paths or boundaries. Without adequate containment, sub-base material can migrate over time, undermining the level surface the preparation work was meant to establish.

Dealing With Existing Irrigation and Services

Existing irrigation systems typically need to be capped, removed or rerouted before artificial grass goes down, since it won’t need watering the way natural lawn does. Any other underground services in the area also need to be identified — a Dial Before You Dig check remains a standard, legally required step even for a landscaping-scale excavation.

What Happens After Preparation

Once excavation, drainage and the compacted sub-base are complete, the site is ready for the turf itself to be laid, jointed and secured — the installation stage that most people picture when they think of an artificial grass project, but one that depends entirely on the groundwork underneath it being done properly first.

Getting the Groundwork Right First

If you’re planning an artificial grass area, it’s worth treating the excavation and base preparation as its own genuine stage of the project — assessed for drainage, existing services and site conditions — rather than an afterthought before the “real” installation. See our landscaping excavation guide for how this fits into broader landscaping site preparation, and our landscaping materials range for sub-base and aggregate products.

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