Impact-absorbing surfacing (IAS) is one facet of play safety on which advice and research is badly wanting, but unlikely to be had for such a small sum.
While recognising that protective surfaces must be installed under play equipment, many are beginning to question the justification in costbenefit terms.
Dr David Ball, director of the Centre for Environmental and Risk Management at the University of East Anglia, argues that insistence on the installation of this surfacing in public playgrounds may also be leading to more injury.
"There is about one child fatality a year in British playgrounds, but surfacing almost doubles the price of playgrounds. So playgrounds are being lost, which in turn means that children play in unsuitable places, where they are more likely to be hurt. In this country about 5,000 children a year are injured in all kinds of accidents because they play in unsuitable places. "
Which is not to deny that IAS itself reduces injury, though research does not always offer straightforward results. While they strongly advocate IAS, of great concern to the National Playing Field Association is the use of dangerously inappropriate surfaces.
Technical director Jean Wenger keeps some horrifying examples of "loose fill" materials which have been used as "safe" surfacing in playgrounds, small logs with jagged edges, splintery, coloured pieces of wood, sawdust-like material which turns into mulch as soon as it rains.
Insist on a certificate stating that IAS has been tested in accordance with BS 7188 (see panel). Jean Wenger's advice is to ask for a sample to be sent and checked before the surfacing is installed. Of equal concern is that appropriate surfaces are sometimes so badly installed or maintained as to render them useless or dangerous.
But even when correctly installed and maintained, IAS is never a panacea. The great majority of accidents in playgrounds involve limb injuries, but such surfacing is primarily designed to reduce the severity of head injuries. Moreover, other safety factors are equally as important.
"What is needed to discover how and why accidents happen is a surveillance programme of playgrounds that looks at total playground design," says Professor Jo Sibert, of the child health department at Llandough Hospital, South Glamorgan and a member of the Cardiff study research team. She joins a chorus asking for more research.
Faced with such difficulties, and with the enormous expense of IAS, it is not surprising that many are asking whether height is such a big deal in providing good play experiences, especially in schools. Looking around they see plenty of evidence that it may not be.
Learning Through Landscapes, a highly-respected charity working to transform school grounds, fosters imaginative, fun projects which contribute to environmental education and other areas of the curriculum. Rarely do they feature any equipment high enough to require special surfacing.
Many, however, would not want to do away with climbing and other fixed equipment altogether, arguing that they develop motor co-ordination and other skills. In which case lower equipment (demanding cheaper IAS) is another option.
Jean Wenger is concerned about those schools with high equipment who still don't have IAS, but counsels schools not to automatically install it.
"First reassess your play provision. Look at play value and the safety of your equipment. You might, for example, have four agility items. Do they meet safety standards? You could spend some of the money available on ripping out some of these and providing, say, a garden or low balance equipment with which you can use low-grade, inexpensive IAS." Result: you will provide a greater range of play opportunities for the same money.
In urban schools in particular, many now argue that grounds should be used to provide environmental experiences or playground games which encourage social and other skills: many schools are painting tarmac surfaces in a way which encourages such games. The debate over IAS could provide a spur for such changes.