The Swing Set Safety Zone: 6 Feet Around, Twice the Beam Height Front and Back, and What Goes On the Ground

The three numbers

Six feet. "Locate play equipment at least 6 feet from any structure or obstacle, such as a house, fence, sheds, trees or poles," and "Provide shock-absorbing protective surfacing material underneath and at least 6 feet beyond the perimeter of the play structure." Twice the beam height. "Swings should be further away from structures to the front and rear of the swings, a distance equal to twice the height of the top bar from which the swing is suspended," and the surfacing extends the same distance. A tire swing gets a circle whose radius is the chain length plus 6 ft. Eight inches. 8 in minimum between swings with limited sideways motion, 8 in between the surfacing and the underside of a suspended seat, 24 in between a disk swing and the support poles, 12 in between lawn swings and poles at 28 in above the seat.

Laying it out

1. Find the beam height in the manual (Swing-N-Slide prints 82 in; most makers print only overall height, which overstates it slightly and is safe to use).
2. Draw the footprint. Add 6 ft on the two ends and on any side without swings.
3. On the swing side and its opposite, add twice the beam height: 82 in becomes 13.7 ft each way.
4. Check the rectangle against every structure, fence, tree and the slide exit. The handbook wants active and quiet areas separated: no sandbox in the swing arc, no slide exiting in front of a swing.
5. That rectangle, not the footprint, is what gets leveled and surfaced.

Swing spacing and slide exits

Disk and tire swings get their own bay: "Place disk swings in separate bays, away from other swinging equipment," and tire swings capable of 360-degree rotation "in a separate bay, away from other play equipment and structures." That is why Gorilla's Frontier and Pioneer Peak put the tire swing on a second beam. The slide exit needs its own surfaced zone and must not face a swing; the handbook also says a north-facing slide gets the least sun. Swing seats should be lightweight, per the handbook, to minimize injury if a child is struck.

What the zone has to be made of

Loose fill (wood mulch, engineered wood fiber, shredded rubber) at 9 in maintained, 12 in as filled, for equipment up to 8 ft; sand or pea gravel at 9 in only for equipment up to 5 ft; 6 in minimum under equipment under 4 ft; never over concrete; contained by edging; topped up as it compacts. Rubber tiles or poured rubber only with an ASTM F1292 report for the fall height. "Grass and dirt are not considered protective surfacing," and "carpeting and thin mats are generally not adequate." The products and the bag math are on best playground mulch and surfacing.

Worked example

Backyard Discovery's Mount McKinley is 186 in wide by 150 in deep (15.5 x 12.5 ft) and 119 in tall; using the overall height as the beam height, twice that is 19.8 ft. If the swings hang along the 15.5 ft side, the zone is 15.5 ft plus 6 ft at each end (27.5 ft) by 12.5 ft plus 19.8 ft front and 19.8 ft back (52 ft), though the back arc overlaps the tower on most sets and the manual's real beam height is lower than 119 in. Call it 28 x 32 ft with the tower inside the rear arc. At 12 in of fill that is roughly 900 cu ft of mulch, or about 580 forty-pound bags at Playsafer's 1.55 cu ft. That is the number a small-yard buyer needs before the set, which is why best swing sets for small yards and best playsets for small backyards do this arithmetic per set.

Surfacing for the zone

Mistakes to avoid

• Surfacing the footprint and not the zone. The child lands 6 ft out, or 14 ft out off a swing.
• Putting the slide exit in the swing arc.
• A disk or tire swing in the same bay as belt swings.
• Calling grass a surface. The handbook does not.
• Letting the fill thin under the swings. Mark the depth on the posts and top up.