The Problems Sometimes Associated With Grass And Play Bark
Artificial grass is becoming ever more popular for play areas. Often the existing areas were formed with grass or play bark, (both of which can have their problems). If the soil conditions are right, the grass receives enough light and not too much traffic, it can make an excellent play area. Often though, the opposite is true, a combination of clay soils, poor drainage, overhanging trees, shading from buildings or fencing and heavy foot traffic, can leave the areas unusable at certain times of the year. There’s often mud, worn out grass and the danger of slipping. Grass surfaces are also not suitable around play equipment with fall heights of more than 1 metre, so often these areas need to be surrounded with another medium.
Some schools we visit have resorted to play bark at one point or another, this can end up just as messy, blows everywhere, needs constant renewal and can hide dangers like bottles and cans. Often these scenarios result in the search for a better, cleaner, safer and easier to clean play surface…
Artificial Grass Play Areas
Increasingly we’re finding that artificial grass can provide the ideal replacement. It’s hard wearing, safe, clean and attractive to the eye. The realism of modern artificial grasses also makes them hard to distinguish from the real thing, unless you’re actually standing on it ! Even then, the look and feel of the grass is very convincing, often the giveaway is that it can look too perfect !
The grass – The play areas featured in this article were all created using Namgrass artificial grass. Namgrass is the residential arm of a company who have been producing quality grass products for over 30 years. They integrate high quality polyethylene (long fibres) with polypropylene yarns (curled thatch), to produce the artificial grass products we use. All the products are manufactured to the highest standards, benefiting from heavy duty latex backing, their unique Tuftlock system and grass fibres (yarns) of only the highest quality. The grass is perforated at approximately 100mm centres to aid drainage.
Preparation – It’s no secret that preparation is the key to most jobs and artificial grass play areas are no different. The first process is to remove the existing turf, (or play bark) and any other vegetation / loose material. The area often has to be excavated to allow for the make up of the play area, (around 100mm), but if the levels can be lifted slightly, this may not have to be done. Excavation, (and especially the disposal of the material), represents a significant cost, so if this can be avoided, we do so.
In most circumstances, (and certainly on clay soils), a stone base is required. Our normal construction is to use a 50mm deep base of wash graded gravel. The “wash graded” description refers to the fact that this material has been washed to remove the clay content often found in gravels and graded to give the right aggregate sizes, (and quantity of fines), to achieve a quality material suitable for concrete mixing. These very properties results in an aggregate that compacts well as a base, yet remains free draining. Type 1 limestone can be used as a base, (a superb material for paving projects), but in our experience it can form an almost impermeable layer that doesn’t aid drainage.
Next we install a bedding layer to enable us to form the accurate and smooth levels that can make or break an artificial grass installation. Our preference is to use a limestone grit. The material we use is a 4-2mm grit, (because it’s readily available), but a 6-2mm is equally as good. The grit layer has no fines at all, (the smallest aggregate size being 2mm), this makes it extremely free draining and a superb material for this use. Sharp sand can be used but our extensive experience with this material in our block paving installations has taught us it’s anything but free draining. In fact, it will hold water for days and turn to a “mush” if it gets too sodden. This isn’t a factor in block paving because the sand layer is kept dry by the blocks. Artificial grass is designed to let all the water through, so it’s horses for courses as far as we’re concerned.
Finally, we lay a weed barrier material. This helps prevent weed growth and aids in the positioning of the grass, (without it the underside of the grass would snag on the bedding layer). Our preference is to use Terram 1000, it’s an extremely strong geotextile used extensively in the construction industry. An added bonus is that it increases the point load capacity because of its resistance to deformation when weighted down over an area.
In circumstances where play equipment is present, foam shock pads may be required. The type and thickness of the pads is dependent on the critical fall height of the equipment. Each installation is unique and advice should be sought in this area to make sure your play area is safe for the children.
In circumstances where the play area is being formed over an existing hard surface, (such as paving, concrete or tarmac), the base construction shown above is not required. We use a Namgrass product called Floweb, Floweb underlay, (pictured on the right below), keeps the backing of the artificial grass clear of the surface, allowing rainwater to flow freely to necessary drainage outlets. In our experience, laying the grass directly on to a hard surface without this kind of underlay will cause future problems because the water can’t flow freely.
Laying the grass – Most artificial grass rolls are available in 4m and 2m widths, 25m long. The grass is rolled out across the prepared base, cut to size and around play equipment with the use of a strong craft knife. If the area is wider than 4m, (or longer than 25m), the grass is joined using a jointing tape in conjunction with a specialist adhesive. We always prefer to use Namgrass’s own products here, because they’re tried and tested and of superior quality. The grass is secured around the perimeter using a variety of means. In some cases we use a pressure treated timber installed when doing the base, the grass is then screwed down to this at regular intervals. In other circumstances, (like heavily trafficked edges or where children are likely to pull at the grass edges), we install a concrete plinth around the perimeter and glue the grass down.
A Sample Of Our Installations
The following examples show artificial grass play areas we’ve installed around play equipment and outdoor gym equipment. The higher equipment will have shock pads underneath.
Installing the artificial grass around shrubs and trees presents no problem. The roots don’t need to be disturbed when preparing the base and they receive water as efficiently as they did previously.
Not all of our installations are so tricky, many involve turning an existing muddy grass play area into an area that can be enjoyed by the children all year around. Our installations are requested by Primary, Secondary and special needs schools as well as nurseries and Childminders. They all face the same problems of how best to deal with an existing, awkward area. Installing artificial grass makes the area more usable, more attractive and requires far less maintenance. A win win all around !
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