Swing Set on a Slope: How to Level the Pad, Contain the Mulch and Anchor the Downhill Side

Why the site has to be level

Three things go wrong on a grade. The set tips: a swing arc on the downhill side loads the downhill posts with every pump, and an A-frame on a slope has less base in the direction it is being pushed. The surfacing migrates: 9 in of loose fill on a slope is 3 in at the top and 15 in at the bottom after the first storm, which the handbook's rain warning is about. And the deck height changes: a 4 ft deck on a 1-in-10 grade is 4 ft on the uphill side and nearly 5 ft on the downhill side, which crosses the handbook's 48 in line where a guardrail becomes a required barrier. The maker built the rails for the height on the box.

How much slope is too much

Swing-N-Slide's published tolerance, level within 3 in across the area, is the only number a maker we cover prints. On a 15 ft set that is a grade of about 1 in 60, which most lawns exceed. So the practical rule is that any visible slope needs a pad. Measure it: a string line and a line level across the footprint plus the 6 ft use zone gives the drop in inches; that is the depth of the cut on the high side or the fill on the low side, or half each. Smaller sets need smaller pads, which is why the swing-only A-frames on best swing sets for small yards are the easiest to place on a sloped lot.

Cut and fill: making a pad

1. Mark the footprint plus the use zone (6 ft all round, twice the beam height front and back of the swings).
2. Strip the turf. Cut the high side down to the level line; use the spoil to build up the low side, compacting in layers. Fill that is not compacted settles, and the set settles with it.
3. Retain the fill on the low side with a timber, block or edging wall high enough to hold the fill plus the 12 in of surfacing the handbook wants as filled.
4. Give the pad a slight fall for drainage, well under the 3 in tolerance, toward the downhill wall, and a way for water to leave; the handbook says to account for drainage.
5. Anchors go into the compacted native soil on the cut side and into compacted fill on the low side only if it has settled; otherwise anchor those posts into the original grade beneath the fill with a longer auger.

Keeping the surfacing on the slope

The handbook: "Use containment, such as digging out around the perimeter and/or lining the perimeter with landscape edging. Don't forget to account for water drainage." On a graded pad the retaining edge on the downhill side is the containment; the uphill cut face is the other. Mark the correct depth on the posts, as the handbook suggests, so you can see when the low side has thinned. Rubber mulch does not decompose and is heavier than wood fiber, which helps on a slope; both makers on best playground mulch and surfacing print a depth chart.

Anchoring on a grade

Every post, downhill first. An auger with a published depth (PlayStar: 15 in, 12-14 in in the ground) bolted to the ground rail per the maker's method (how to anchor a swing set). Backyard Discovery's Durango ships an auger for each of its four legs and steel corner supports, which is the design a sloped lot wants in a swing-only set. Do not rely on the fill side: an auger in loose fill holds nothing, which is the same rule Backyard Discovery gives for sand.

The parts that fit

Mistakes to avoid

• Shimming the downhill legs with blocks instead of grading. The set is level; the ground under the swing arc is not.
• Building the pad the size of the set, not the use zone. The child lands 6 ft out.
• Anchoring into fresh fill.
• Forgetting the deck-height rule: check the guardrail height against the downhill grade after the pad is built.