Grass Mat Standards - Testing for Safety Surfacing

Does your grass mat surfacing conform to the standard? Our clients often ask us these sorts of questions.

And honestly, it’s a question that all buyers should be asking when it comes to safety in playgrounds. We aim to answer the most common questions you have about our grass mat standards.

If you have more questions, feel free to leave a comment or get in touch on our contact page.

What is the grass mat standard?

The British Standard, BS EN 1177 (2018), is a method for determining the impact reduction of playground surfacing. It defines a “Critical Fall Height” for surfacing, which represents the upper limit of the surface’s effectiveness in reducing head injury.

What do the tests involve in order to meet this standard?

Testing provides a method for assessing safety surfaces. In accordance with EN 1177 (2018), test specimens are struck with an instrumented headform from different drop heights.

The instrumented headform measures impact energy to determine the head injury criterion (HIC) and peak acceleration (gmax). The certificated Critical Fall Height is the lowest drop point that produces a HIC value of 1,000 or a gmax value of 200.

Are there different types of tests?

Technically, yes, there are two types of test conditions – concrete base and field base tests.

The grass mat standard stipulates that all laboratory tests shall be carried out on a flat, rigid concrete surface. These are known as concrete base tests. Alternatively, they can be tested on a substrate of sufficient mass, density, and thickness.

Products installed on natural materials intended to influence their performance (e.g. soil) cannot be meaningfully tested in the laboratory. Grass base tests cannot indicate the performance of the product under alternative conditions or in other locations. For example, on a clay-based soil, it is almost certain to achieve a greater critical fall height when the base is wet as opposed to during dry periods.

When a supplier quotes a certification for a specific fall height that sounds too good to be true, they may have done a grass base test. You should always check with your supplier. Ask for proof of certification for concrete tests, as these will give the most accurate results.

Always remember to ask your supplier to clarify exactly what ground conditions their product has been tested on. E.g. the test may state the mat was tested with a 140mm soil layer and mesh on a grass base. You will need to replicate these conditions on site in order for the grass mats to comply with their certification.

What if the product is part of a system?

Our SmartPlay product is installed as part of a system, with a few different variations available. For products intended to be laid over another layer, the entire system must be tested. This is the case for our SmartPlay shock pads. This is classed as a composite product so all its layer(s) must be tested to BS EN 1177 (2018).

Always remember to ask your supplier to clarify exactly what ground conditions their product has been tested on. For example, if the test states the mat was tested with a 140mm soil layer and mesh on a grass base, you will need to replicate these conditions on site in order for the grass mats to comply to their certification.

With regard to the construction of the Grass Safety Matting we recommend you use a supplier that offers a minimum 5‐year guarantee on its product, can provide a flammability test certificate and can supply spares and support if problems arise in the future.

If you have any more questions on grass mats, the grass mat standard, or the SmartPlay system, feel free to leave a comment, or email us at info@playsmartuk.co.uk or call us on 01564 742811.