Thickness is the first number everyone asks about — and the one most often chosen for the wrong reasons. This guide explains what actually drives the decision, which standards set real requirements, and how to avoid the two expensive mistakes: buying a pad too thin for the fall height, and paying for thickness you do not need.
A shock pad (also called underlay, underlayment or e-layer) sits between the sub-base and the artificial turf. It is doing four separate jobs, and thickness only directly affects the first one:
Only the first is governed by thickness alone. The other three depend on density, cell structure and drainage geometry — which is why two pads of the same thickness can perform completely differently.
The table below shows the ranges normally specified in each application. Treat these as starting points for a conversation with your supplier, not as a design.
| Application | Typical pad thickness | What actually governs the number |
|---|---|---|
| Garden / residential lawn | 10–20 mm | Comfort and drainage only — no formal fall-height requirement |
| Pet areas and dog runs | 10–20 mm | Drainage and hygiene; comfort is secondary |
| Rooftop, balcony, podium deck | 15–30 mm | Drainage and weight loading — drainage is usually the binding constraint |
| Multi-use games areas, light sport | 20–30 mm | Player comfort and surface consistency |
| Playground, fall height up to 1.5 m | 10–20 mm | EN 1177 / ASTM F1292 — the assembled system, not the pad alone |
| Playground, fall height 1.5–2.5 m | 20–40 mm | Same standards; thicker pad is one of several ways to reach the number |
| Playground, fall height 3 m and above | 40–50 mm+ | Same standards; often needs a higher-performance pad, not just a thicker one |
| Football / rugby (FIFA Quality, Quality Pro) | 20–40 mm typically | EN 15330-4 and the FIFA test manual — again, the whole system is tested |
In Europe, EN 1177 is the standard for playground surfacing. It defines a Critical Fall Height (CFH) — the greatest fall height at which the surface still passes. The pass criteria are a Head Injury Criterion (HIC) at or below 1000 and a peak deceleration at or below 200 g.
In the United States, ASTM F1292 sets the same two thresholds — HIC ≤ 1000 and G-max ≤ 200 — using a different test protocol.
The critical point for buyers: neither standard rates a pad on its own. What is tested is the complete assembly — turf, infill, pad and base together. A certificate states the CFH for one specific combination at one specific pad thickness. Change the pad, change the thickness, or change the infill, and the certificate no longer applies; the system has to be re-tested.
Under the FIFA Quality Programme, a layer counts as a shock pad only if it contributes at least 20% peak shock absorption, and it must then meet EN 15330-4. FIFA's laboratory requirements for shock pads include:
Note how little of that list is about thickness. A pad that is 30 mm thick but drains at 200 mm/h will fail a FIFA specification at any thickness.
There is no equivalent standard for a garden lawn or a dog run, so the decision is yours. In practice it comes down to drainage and comfort: enough thickness that the surface does not feel like concrete, and enough drainage capacity that water never stands on it.
When you compare shock pads, ask for these five properties. They are what separates a real specification from a thickness figure scribbled on a quotation.
| Property | What it tells you | Reference test |
|---|---|---|
| Density (kg/m³) | How much material is in the pad — drives stiffness, durability and consistency between batches | — |
| Vertical water infiltration (mm/h) | How fast water passes straight through; the main defence against ponding | EN 12616-1 |
| Horizontal flow (L/s·m) | How fast water moves sideways — needed where the base cannot accept water quickly | EN 12616-2 |
| Tensile strength (MPa) | Resistance to tearing during installation and in service | EN 12230 |
| Deformation / thickness (mm) | How much the pad compresses under load — predicts whether the surface stays even | EN 1969 |
Closed-cell XPE foam does not absorb water. That is an advantage — the pad will not become a sponge, will not gain weight in service, and will not support mould growth the way an open-cell material can. But it also means water has to be given a route: through the pad, and then out through the base.
Drainage performance therefore comes from geometry, not thickness — the channel pattern on the underside, any perforations, and how the pad interfaces with the sub-base. A 40 mm pad with a flat underside will pond more readily than a 20 mm pad with formed channels. If you are installing over a roof membrane, a podium deck or heavy clay, drainage should be the first question you ask, not the last.
If you are preparing an RFQ, these six lines will get you comparable quotations instead of a wall of different numbers:
You will find that we publish property values only where we can evidence them. Where a value is marked under testing, it has not yet been independently verified, and we will not quote you a figure we cannot stand behind. If a project requires EN 1177, ASTM F1292, EN 15330-4 or FIFA documentation, tell us the requirement and we will tell you honestly what we can and cannot currently provide — including when the answer is that you should buy elsewhere.
Our EcoDrain range is produced in 20 mm, 30 mm and 40 mm from 100% recycled XPE, in interlocking sheets of 2290 × 940 mm. See the full specification →