The problem with assessing an installation is that the mistakes that matter most are buried. By the time the surface is rolled out and brushed, the base is invisible and you are judging the one component you cannot inspect.
You can, however, read a great deal from the finished surface if you know what to look at. Here is what to check on handover day and in the weeks after, and what each observation tells you about the work underneath.
On Handover Day
Walk the Surface Barefoot
Feel for firmness and consistency. A properly compacted base feels uniformly solid. Soft spots, areas that give underfoot, or a sense of walking on something slightly loose all indicate inadequate compaction or an unevenly spread bedding layer.
This is the single most informative thirty seconds you will spend, and it is far easier to raise on the day than in six months.
Look Along the Surface at a Low Angle
Crouch down and sight across the lawn from one end. Undulations, dips and high points are obvious from this angle and almost invisible from standing height. A well screeded base produces a plane. A rushed one produces gentle waves.
Inspect the Joins
Find the seams. On a good job you will struggle. Look for:
- Any gap between the two pieces, which will widen over time
- A visible line of different shade, which suggests the rolls were laid in opposing directions
- Pile lying differently either side of the seam
- Adhesive or seam tape visible at the surface
Directional error is the most consequential of these because the only remedy is relaying.
Check the Perimeter
Every edge should be mechanically restrained, whether by timber, composite, aluminium or by being secured into an existing hard edge. Push a foot against the edge in a few places. It should not lift or move.
Edges left unsecured curl within a year, and once curled they collect debris and become a trip point.
Assess the Infill
Part the pile in several places, including in corners and along edges. Infill should be present, evenly distributed, and sitting at a consistent depth. Corners and edges are where it is most often skipped, because brushing material into a corner is fiddly.
Underfilled surfaces mat early, and the symptom appears about eighteen months after the crew has left.
In the First Few Weeks
Watch It Rain
The most valuable test available and it costs nothing but patience. After a decent downpour, look for standing water. A correctly built system clears surface water within minutes.
Pooling indicates either an inadequate drainage layer, insufficient compaction allowing a depression to form, a blocked or absent outlet, or a fall running the wrong way. All are base issues and all are warranty matters.
Look for Ripples
A wave or bubble appearing in warm weather indicates the sheet expanded and had nowhere to go, which usually means it was laid without being allowed to relax before fixing, or the perimeter was over restrained.
Quality synthetic grass should be laid out and left for a period before cutting and securing, so the material reaches ambient temperature and settles. Skipping this step to finish in a day is a common shortcut.
Check Around Fixed Objects
Cuts around downpipes, posts, taps and garden bed edges should be neat and tight. Gaps get filled with debris, and debris in a gap is where weeds start.
Longer Term Warning Signs
Over the first year or two, these indicate an underlying problem rather than normal wear:
Persistent damp areas or odour. Drainage failure, not a product issue.
Localised sinking. Base settlement, usually from compaction in one thick lift rather than several thin ones.
Uneven fading. More likely a product quality issue than an installation one, and a warranty matter with the manufacturer.
Weeds emerging through the surface rather than at the edges. Suggests the weed barrier was omitted or the existing vegetation was not properly killed.
Seams opening. Adhesive failure or inadequate seam preparation.
Raising Problems Effectively
If something is wrong, the approach matters. Photograph it, including a wide shot for context and a close shot for detail. Note the date and the weather conditions, particularly for drainage issues. Refer to the written scope in your quote. And raise it in writing rather than by phone, so there is a record.
Most reputable installers will return and fix genuine defects without argument. The ones who will not are generally the ones whose quote looked unusually attractive, which is the argument for choosing on scope and reputation rather than on price alone.
The Preventive Version
Everything above is easier to avoid than to remedy. Ask for the base specification in writing before work starts, ask how many compaction passes and at what layer depth, ask whether the material will be relaxed before fixing, and ask what perimeter restraint is included. An installer who answers those four questions confidently is unlikely to produce a job with any of these faults.