If you want to know what is the best material to put under a swing set, this guide will give you all the information you need to make the right choice.
While there is no material that can totally guarantee your child will remain injury free (especially if they like to jump off the swing set!), installing a good protective surface will greatly reduce the risk of injury. And it can look good in the backyard too.
Below, we’ll cover the pros and cons of each of these surface materials and highlight which is best – for safety, durability, value and maintenance.
Why Put a Surface Material Under a Swing Set?
Even with supervision, a time will come when one of your kids falls off, loses their balance or is flung off the swing set when getting a bit over excited using it. The higher the fall, the bigger the impact when they land! Kids will be kids and at times will take risks and push themselves past their capabilities. This is how they learn.
You need to provide a surface with at least some shock absorbing capabilities, otherwise you risk your child having unnecessary scrapes, cuts, bruises, broken limbs or worse. Some surfaces absorb the shock of a fall better than others. You want the surface to absorb the shock, not your little one’s young body!
There are many types of surface materials out there to suit a range of budgets. In the guide below, you can quickly find out what to put under a swing set in your backyard.
Our Top Recommendation
Popular materials to put under a swing set in the backyard include rubber mulch, pea gravel, wood mulch, sand, rubber mats and grass. But which is the best?
The quick answer to what is the best material to put under a swing set is rubber mulch – except for sets used by toddlers where rubber mats are more suitable (to avoid the risk of choking on bits of mulch).
Rubber mulch provides the highest level of protection out of all the surface materials. It costs more upfront but, in the long run, is a good investment as rubber mulch is very durable and won’t need replacing regularly like other loose-fill materials.
You’ll also come to appreciate how little maintenance is required with rubber mulch. Less time spent maintaining the surface means more time relaxing for you and more time for your kids to play with their friends on the swing set!
If you’re not yet sure what swing set to buy, check out our recent article on the best swing sets for kids in 2022 for reviews, a buying guide and FAQs.
Unsuitable Surface Materials
All solid, hard materials are unsuitable as a surface layer under a swing set as they offer very little, or no, shock absorbing qualities. It may surprise you but grass is one of them!
Unfortunately grass under a swing set is the most common material found in backyards – usually because it already grows there so seems an easy, free material to build a swing set on top of.
We say ‘unfortunately’ because grass under a swing set is not a good material for the safety of your kids, or for long term cosmetic appeal. There are good reasons why grass is not used as a surface under swing sets in public playgrounds…
Dry weather (when kids are most likely to play outside) can make the ground rock hard, which provides very little protection if they fall off the swing set. In fact grass has the lowest impact resistance of any popular material used under swing sets.
Wet weather also makes grass slippery which is dangerous for little ones if they jump off the swing set or run around it.
That luscious green grass, that looks amazing in spring, is quickly worn away if a swing set is used often. It may re-grow next year but, for most of the outdoor play season, it will remain a slippery or hard patch of dirt, not a protective surface to cushion kids if they fall on it…
If your budget means that having grass under a swing set is the only option, take some reassurance from knowing that if the ground is still moist and not compacted, it is nowhere near as unsafe as concrete or asphalt! But you may want to buy some protective gear for little elbows and knees, for when that tumble comes.
One option to protect your grass is to lay grass mats for a swingset – these are rubber ring mats that let the existing grass grow through them but stop it getting as churned up. See the section on Poured Rubber and Rubber Mats below for more details.
You might be swayed by the idea that artificial grass looks like grass but with the benefit of never having to mow it. However, you might have to wash it… And its lush green coloring can quickly look quite out of place if real grass surrounding it dries up and goes brown in the height of summer.
As a protective surface, it offers only marginally more impact resistance than real grass. For an extra cost, you could install some shock pads underneath but it is still going to be a relatively firm landing surface if your kids fall on it. On the plus side, it can have better drainage than real grass so may get less slippery and remain slightly more cushioned.
But artificial grass is very costly to buy and install. If you’re going to all that expense, why not install a surface material that is known to be much better at protecting your kids?
- Flagged paving
- Decking boards
- Dirt (which can become rock hard and compacted over time)
All these materials are unsuitable as they offer very little, or no, shock absorbing qualities
Suitable Surface Materials
More protective and longer lasting materials to put under a swing set include loose-fill materials (rubber mulch, wood mulch or chips, sand or pea gravel) or rubber mats.
We’ll review each of these materials in turn – the level of protection they offer, relative costs, how much maintenance they need, how visually appealing they are and any drawbacks.
Rubber mulch is often designed specifically for use as a surface in play areas for kids. If it complies with ASTM F1292 standards then it meets the legal requirements for high traffic areas in a public playground. So you can be confident it will be good enough for your backyard swing set.
If buying rubber mulch that is not designed for playground use, check it carefully before laying to ensure there are no shredded pieces of metal in it – these may occasionally occur as part of the shredding process.
- Most effective loose-fill material for shock absorption – 6″ offers protection for falls from a height of 10 feet
- Doesn’t attract insects
- Lowest ongoing cost – takes years to degrade so may never need to be replaced
- Least maintenance required of all loose-fill materials
- Just needs raking occasionally to keep evenly distributed
- Recycles old tires
- Available in a range of colors
- Highest initial cost of any loose-fill material
- Doesn’t suppress weeds as much as wood mulch
- Flammable – toxic fumes if burned (but fires are very uncommon)
Wood Chips or Wood Mulch
Wood chips provide slightly higher impact resistance but the cheapest option is going to be landscaping wood mulch. However, Engineered Wood Fiber (EWF), which looks very similar, has been designed specifically for use as a surface material in play areas.
Wood mulch under a swing set that complies with safety standard ASTM F2075 would meet the legal requirements for use in a public playground, so you can be confident that it will be good enough for your backyard.
But do take care to avoid using wood mulch under a swing set if it has been made from pressure treated wood that has involved the use of chromated copper arsenate (CCA).
- Good shock absorption – 9″ offers protection for falls from a height of 10 feet (chips) or 7 feet (mulch)
- Absorbs and drains rain water well
- Offers relatively good slip resistance
- Lower initial cost than rubber mulch
- Widely and readily available
- Easy to rake back into place
- Color looks natural in a garden setting
- Helps controls weeds
- Environmentally friendly product
- Risk of splinters
- Needs regular topping up
- Easily displaced in high traffic areas
- May attract undesirable insects
- Can go moldy
- Freezes in winter making it too hard for safe use
Pea gravel under a swing set is readily available, quite cheap and has fantastic drainage but doesn’t offer much impact resistance. It does look quite natural in a backyard setting but may also need regular topping up.
- Stays relatively clean (rain washes dirt off)
- Inhibits the growth of microbial organisms
- Low initial cost
- Natural product and color looks natural in a garden setting
- Stays in place better than sand
- Second least effective loose-fill material for shock absorption – 9″ only offers protection for falls from a height of 5 feet
- Second worst loose-fill material for those with mobility issues to maneuver on
- Cats or wildlife may use it as a litter box
- Breaks into smaller pieces over time, compacting to a hard landing surface
- Needs to be replaced regularly, but not as often as sand
- Gets scattered easily – needs frequent raking to level it out
Sand under a swing set is also a cheap material and the type of sand suitable for play areas (softer than building sand) is readily available in large quantities. But it provides the least impact resistance of any loose-fill material.
- Low initial cost to install
- Widely and readily available
- Natural product
- Color looks natural in a garden setting, if it is kept clean
- Can double up as a sand pit for kids to play in
- Worst loose-fill material for shock absorption – 9″ only offers protection for falls from a height of 4 feet
- Can get hard when wet or damp, offering even less protection
- Worst loose-fill material for those with mobility issues to maneuver on
- Cats or wildlife may use it as a litter box
- Attracts insects – especially ants!
- Scatters easily or blows away
- Needs the most raking and topping up
Poured Rubber and Rubber Mats / Tiles
Poured rubber is the safest surface for a play area but you would need to ask a professional to install it. It is also very expensive – it is really only suitable for large public playgrounds. If considering it, check with your installer that:
- the surface they are providing meets safety standard ASTM F1292
- they are installing two layers – a wear layer and a cushion layer
Rubber grass mats for a swingset are interlocking tiles (usually about 1 inch thick) that are laid on top of existing grass to cover an entire play area – the grass can grow through the holes in the mat. These provide excellent protection and are the best material to put under a swing set for toddlers.
Because, unlike loose-fill materials, rubber mats for under swing sets do not present a choking hazard for toddlers. They do need to be secured by pegs and/or cable ties though, to keep them securely fixed to the ground.
However, swingset mats can be very expensive if you need to cover a large play area. Smaller rubber mats for under swing sets (often known as fanny pads) can help protect kids in high traffic areas under a swing or slide – preferably used on top of another (not solid or hard) surface.
- Play area is more accessible by those with mobility issues
- Available in different thicknesses to suit swing sets of different heights
- Less likely to be used as a litter box by animals
- Lowest ongoing cost as takes years to degrade – may never need to be replaced
- Low maintenance – just sweep or wash when necessary
- Many colors and designs
- Environmentally friendly (if the mats use recycled rubber)
- High initial cost – more than all other loose fill surfaces
- Poured rubber needs a professional to install
- Some kids may have latex allergies or dislike the smell
- Flammable and gives off toxic fumes when burning (but fires are very uncommon)
How Deep Should Loose-Fill Materials Be?
The following table is taken from the US Consumer Product Safety Commission’s Public Playground Safety Handbook which lists what to put under a swing set:
Fall Height (feet)
With the exception of rubber mulch, loose-fill materials are likely to settle and compact by at least 25% as time passes. So you should factor this in when working out how much you need to purchase. For example, if a minimum depth of 9″ is required, lay the loose-fill material to a depth of 12″ to start with.
If you have the budget, don’t be afraid to use more loose-fill material than is specified as a minimum – the deeper it is, the more cushioning there will be if your child falls on it.
Notes About All Loose-Fill Materials
Give consideration to the surface that you lay your loose-fill material on. If there is inadequate drainage the material may compact and degrade faster, so you’ll need to top it up more frequently. If necessary, prepare the site in advance.
Be aware that most loose-fill materials require regular maintenance to maintain the minimum depth. Especially the areas under swings, slides or jumping off points as the material will be scattered more quickly there. It can be helpful to place markers on the uprights of the swing set to easily see where the minimum fill level is.
Also note that no loose-fill material meets legal requirements for public toddlers’ playgrounds as they all present a potential choking hazard. While you do not have to meet these legal requirements in your own backyard, you might have greater peace of mind avoiding loose-fill materials where toddlers play. Rubber mats under a swing set are safer for toddlers.
- Readily available
- Easy to put in place
- Non-rubber options are relatively cheap
- Can be environmentally friendly and visually appealing
- Not suitable for toddlers
- Worse for those with mobility issues than poured rubber or swingset mats
- Less effective if the ground is frozen
- Need regular raking to keep level
- Non-rubber options need topping up from time to time
- Can be scattered onto surrounding areas
- Non-rubber options can attract insects
- Cats and animals may use the filled area as a litter box
Size of Protective Surface Required
As a general rule, the protective material that you install under a swing set should extend 6 feet in all directions beyond the swing set.
If there is a slide that is taller than 6 feet high – extend the protective surface at the bottom of the slide even further, so that it is at least as long as the slide is high.
Where there are regular swings – extend the surface in front of and behind the swings to a distance that is twice the length of the swing chains.
If there are tire swings – extend the surface in all directions around the tire swing to a distance that is the length of the swing chains plus 6 feet.
See our article on the best swing sets for kids for reviews, a Buying Guide and FAQs with more details and tips.