A sandpit is one of the best things you can add to a family garden. It's cheap to build, keeps kids busy for hours and lasts for years. Here's how to build one that drains well, stays clean and is filled with the right sand.
Choosing the spot
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Partial shade is ideal. Full sun makes sand hot in summer; deep shade keeps it damp and mossy. Somewhere with afternoon shade from a tree or the house works well.
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Within sight of the kitchen or deck for easy supervision.
- Away from trees that drop sap, berries or lots of leaves.
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On level, free-draining ground. Avoid low spots where water collects.
Building it
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Mark out the size. 1.5m × 1.5m suits one or two small children; 2m × 2m gives room for friends.
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Dig out the turf and level the base. Digging down 100–150mm means the frame doesn't need to be as tall.
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Build the frame from sleepers or boards about 300mm high. Choose timber suitable for ground contact and play use, and sand any rough edges and corners. A wide top board doubles as a seat and a place for sandcastle production.
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Lay a permeable liner such as weed mat over the base. It lets rain drain away while keeping sand separate from the soil and stopping weeds and worms coming up. Don't use plastic, which traps water.
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Fill with sand to about 50mm below the top of the frame.
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Make a cover. A fitted lid or a tarp held down with weights keeps out cats, leaves and rain.
Which sand?
Daltons No1 Washed Sand is used in school sandpits. It's mined from the ancient Waikato riverbed in Matamata, then washed and screened, so it's clean and contaminant-free with an even particle size. That means good drainage and sand that holds its shape for building.
Avoid builders' or fill sands that contain silt and clay. They get muddy when wet, stain clothes and drain poorly.
How much sand do I need?
| Sandpit size |
Sand depth |
Volume |
Order |
| 1.2m × 1.2m |
250mm |
0.36 m³ |
½ m³ |
| 1.5m × 1.5m |
250mm |
0.56 m³ |
1 m³ |
| 2m × 2m |
250mm |
1 m³ |
1 m³ |
Sand is heavy, around 1.5 tonnes or more per cubic metre, so ½ m³ may be all a standard trailer can safely carry. Check your trailer's rating. More in How Much Do I Need?
Keeping it fresh
- Keep it covered when not in use.
- Rake it over every week or two to let it air and dry, and to remove debris.
- Top up each spring as sand gets carried out on feet and toys.
- Replace the sand completely every couple of years, or sooner if it's been contaminated.
Finishing the surrounds
A ring of bark around the sandpit catches spills and gives a softer landing than hard ground. Ornamental Bark No4 or Bark Nuggets No5 work well.
Quick answers
Is washed sand safe for kids? Daltons No1 Washed Sand is washed and screened to remove contaminants, and is used in school sandpits.
How deep should the sand be? 200–300mm gives plenty of depth for digging without kids reaching the liner.
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