However, another factor is every bit as vital to the aesthetic, safety, and overall ‘feel’ of a playground, but is far less ‘surface level’ than the others – although in actual fact, it is the surface!
Not only is a space’s surfacing the foundation upon which all of its most exciting features stand, it also determines whether it’s even useable at all. In times gone by, playgrounds could be constructed atop a huge array of materials (with far less regard for the safety of the child), but today, much stricter regulations are in place.
The benefits of this change, or indeed its potential adverse effects, are keenly debated – but either way, it means that playground manufacturers like us are compelled to use a number of tried and tested materials in our work, each with their own strengths and challenges.
Our decades of play experience has given us a wealth of knowledge about all of them, and below, we’ve outlined everything you need to know.
Mainline Surfaces
Wetpour
Perhaps the most commonly used modern safety surfacing, wetpour is constructed from recycled rubber granules and polyurethane binders, and freshly mixed on-site. This results in a dense, consistent material which can literally be ‘poured’ onto the ground to form a smooth surface.
This process is achieved using two layers, making wetpour slightly more time consuming to install than other materials, but it also produces an extremely resilient, hardwearing surface, free from joins, seams or trip points. The first layer, or ‘base layer’, is made up of coarse black granules derived from recycled tyres. The second layer, or ‘wearing layer’, consists of much finer rubber granules, and as the visible surface, it is the one that delivers the vibrant colours and patterns that wetpour is known for. Once laid, the surface can take between 24 and 48 hours to fully set, depending on the ground and weather.
The advantages of using wetpour are numerous: its shock and impact absorbency reduces the risk of serious injury, and its smooth, level state makes it comfortable to walk on, and ideal for wheelchairs and buggies (boosting the inclusivity of any space in which it is installed). Its great durability also makes it attractive for local authorities, as is it virtually maintenance free, and its porous nature gives it excellent resilience in the face of extreme weather.
It is also extremely versatile: not only is it ideal for installation around uneven surfaces, it can be laid to different depths, which is essential to meet the Critical Fall Heights (CFHs) of the equipment it surrounds, and aesthetically, a huge variety of engaging elements like animals, shapes and numbers are all easy to render in wetpour. This can even extend to three dimensional formations such as sharks or ladybirds, adding some extra play value to any playground.
Of course, whether it is truly the best choice of surface will differ from space to space. For those seeking a more naturalistic aesthetic (most likely in rural areas) other options may be more appropriate – likewise if budgets are very tight, and extensive groundworks are not viable. Additionally, whilst wetpour can be laid onto a dynamic crushed stone layer, as well as various existing hard surfaces, it cannot be laid directly onto grass. Instead, an engineered solid foundation such as stone or concrete will be required – a situation which can add time and expense to an installation.
Rubber Mulch
Of course, wetpour is far from the only prominent safety surfacing; in our work, another of the most commonly used is rubber mulch.
Like wetpour, mulch is made from recycled rubber (its shreds are generally comprised of over 90% used car tyres) in a tough polyurethane polymer – this majority recycled constituent makes both surfaces much more environmentally friendly. It is bouncy and soft, and will act as a durable surface for children in the hustle and bustle of play – and as with wetpour, it can be tailored to meet the CFH of any piece of equipment that it surrounds.
It is designed to be easy to install, and is fine-tuned to cut out the need for specific ground preparation. Like wetpour, once laid it can take between 24 and 48 hours to fully set, depending on the environment. Crucially, however, mulch can also be laid on grass, without requiring the use of a solid foundation, and unlike wetpour’s required two layers, a single layer of mulch is sometimes sufficient (depending on the existing surface).
Aesthetically, mulch comes in an array of different colours, but these tend to be more subdued, subtle shades than the vibrant colours generally associated with wetpour. This matches mulch’s grainy, bark chipping-like appearance, and makes it much more suitable for rural areas.
Of course, as with any surfacing, mulch’s unique collection of properties make it ideal for some spaces and a poor fit for others. In terms of cost, it is cheaper than wetpour but still more expensive than other prominent surfaces. Likewise, whilst it is every bit as durable as wetpour in the face of the elements (being porous and quick drying), its structure can make it more prone to water logging, which is important to bear in mind for playgrounds which experience more extreme weather.
Grassmat
In some circumstances, however, both wetpour and mulch may represent too big a time or cost expense. In this case, rubber grassmat is a very popular alternative, and provides a cost-effective option for a variety of play spaces.
The mats, which are cut to fit perfectly around equipment once it has been installed, are laid on top of existing grass or turf surfacing, and offer a softer impact for trips or falls than harder surfaces such as tarmac. In addition, grassmat is incredibly straightforward to install when compared to more elaborate surfaces, needing simply to be laid and then secured to the ground using durable fixings.
The holes in grassmat fulfil multiple purposes. Not only do they allow for drainage (making this another durable surfacing option against the elements) but they also enable the underlying grass to grow through over time, eventually becoming virtually invisible to the untrained eye. This can be very beneficial for local authorities if the space sits in a well-preserved rural location, for instance, or if the community is sensitive about the local aesthetic being impacted.
When considering maintenance, grassmat is one of the least demanding surfaces available, requiring only occasional sweeping or rinsing, and in terms of safety, whilst it can’t be installed to suit different CFHs in the same way that pourable surfaces can, it can be tested to meet many different safety criteria – the grassmat we utilise in our own designs, for instance, is certified for up to 3.3m.
Overall, while grassmat may lack the tactile impact or visual wow factor of other surfaces, it provides a simple, cost-effective option for designs with tighter budgets, and it is especially useful in conserving a space’s natural appearance. For these reasons and more, it continues to be one of the most commonly used surfaces in our work.
Lesser-Used Materials
Although these three surfaces are by far the most prominently used, other materials may also be appropriate depending on the location, the expected visitor base, the intended audience for the playground and more. These regularly find their way into our designs, and they include:
SUDS Bond® Paving
Most commonly used for pathways in or around a play space, SUDS Bond is a water permeable surfacing system, and as with rubber mulch, it is derived from a blend of naturally decorative aggregates and recycled granules from used tyres.
The great benefit of SUDS Bond is its excellent drainage, which makes it ideal for areas that may be at greater risk of flooding (hence its full name: Sustainable Urban Drainage Solution). When properly installed with correct groundworks, SUDS Bond offers effective water drainage of 1600mm per hour.
After being mixed on site, it is hand laid and can typically take between 6 and 24 hours to fully cure, after which it will have excellent grip and toughness. It is suitable for pedestrian, bicycle and equestrian traffic, and delivers excellent accessibility for wheelchairs, prams and buggies. It is also considered environmentally sound, as its construction from recycled tyres is an excellent repurposing of an existing wasted resource.
The main challenge with SUDS Bond usually arises during the installation phase, as it is not recommended to lay it during periods of rain or at temperatures below 10°c.
Bark Fill
Bark Fill is an aesthetically ideal surface for woodland play spaces such as parks, and it’s also relatively cost effective.
However, like all materials, it comes with its own challenges: as a loose fill surfacing, it is likely to become displaced after a period of use (particularly underneath moving play equipment), and the correct depth of loose fill will therefore need to be maintained via replenishment.
Nevertheless, if these requirements can be properly managed, Bark Fill is a solid, visually cohesive and very tactile option for rural playgrounds.
Play Sand
While less commonly seen in new designs, sand remains a popular and natural surface in some spaces. It has an obvious visual appeal for seaside playgrounds, or those aimed at younger children that seek to capture the ‘sandbox’ feel of nurseries or pre-schools. It also adds a bonus play feature to any space, as children delight in building sandcastles, digging for treasure, or creating their own fun and games with it.
In terms of regulations, sand needs to be laid and maintained to a minimum depth of 300mm to comply with BS EN 1177, and its depth should be 100mm more than that required to meet the equipment’s CFHs.
Another key consideration with sand is its impact on a play space’s physical inclusivity; wheelchairs may struggle to traverse it, for instance, as could parents with buggies. However, as with every surfacing option, it is for local authorities (in consultation with residents) to weigh up these potential challenges, before making the right decision for the needs of the community.
The Foundations of Fun!
Safety surfacing is the foundation of a playground’s fun, and getting it right is crucial; every project we complete reminds us that there’s no perfect, one-size-fits-all material, because every space is different. Most importantly, we never forget that whether we’re dealing with wetpour, mulch, grassmat or anything else, its presence is sure to shape the experience of every young visitor that steps into the playground – even if most will never notice it at all.
