What is the maximum free height of fall for a loose playground safety surface?
The maximum free height of fall for a compliant loose playground safety surface is up to 200 cm with an installed depth of 30 cm and up to 300 cm with 40 cm. A free height of fall above 300 cm is not permitted for playground equipment.
Shock absorption in play sand, gravel, wood chips and play bark is provided by the loose layer and its voids. In service, performance depends on particle size and shape, fines content, layer depth, substrate, moisture and temperature. The material table in BS EN 1176-1 specifies the particle sizes: play sand must be washed and graded from 0.02 to 0.2 cm; gravel must be rounded, washed and graded from 0.2 to 0.8 cm. Neither sand nor gravel may contain silt or clay particles. Wood chips must be mechanically shredded wood graded from 0.5 to 3 cm, excluding wood-based materials and bark or leaf content. Play bark consists of shredded conifer bark graded from 2 to 8 cm.
Fines from wear, soil or gritting material can fill the voids, allowing the particles to interlock and substantially reducing shock absorption. The installed depths of 30 cm and 40 cm each include a 10 cm allowance above the minimum depths of 20 cm and 30 cm because loose material is displaced during play. Hollows can form at impact points, leaving insufficient layer depth; a clearly visible marker on the playground equipment shows the required fill level and allows the layer depth to be checked in service. The construction must drain water so that the loose layer is not wetted from below, while a separation layer prevents mixing with the soil. Depending on the location, root protection may also be required to prevent roots growing up from below.
Moisture can compact play sand and reduce its shock absorption, while prolonged rain can make loose play bark slippery. Play bark decomposes and loses volume. Frozen loose materials can lose the required shock absorption, in which case the affected playground equipment must be taken out of use. In winter, neither grit nor salt applied to melt ice should be used on the impact area. Different loose materials should not be mixed, as mixing can alter the particle-size distribution, invalidate the table classification and reduce shock absorption. To retain layer depth and shock absorption in service, the loose layer requires regular maintenance: at impact points, check the depth and top up to the marker; loosen and redistribute the material evenly; remove leaves, glass, animal faeces and decomposed play bark; and clean or replace contaminated play sand.
A loose-fill surface can be verified using the material table in BS EN 1176-1 where the material type, particle size, cleanliness and installed layer depth meet its requirements; no additional test report for critical fall height under BS EN 1177 is then required. For other loose materials or layer depths, the critical fall height must be determined in accordance with BS EN 1177. This classification remains valid only while the requirements are maintained in service. Inspections follow BS EN 1176-7: the operator sets the frequency of routine inspection according to use, location and risk; operational inspection is carried out every one to three months or in accordance with the manufacturer's instructions; and the annual main inspection is undertaken by an independent competent person.