August 16, 2014 by Dadinator
It’s existed in our minds for months now, sitting there looking wonderful. It was overlaid on our vision of the backyard, like special effects, but that cheap version called imagination. It morphed over time, changed size and position, but it has been there for a while. It was a promise to our kid’s that they couldn’t understand, but against which we measured ourselves as parents. Who promises a sandpit and doesn’t deliver? Not this mum and dad, I’ll tell you that.
It was all The Mamanator’s idea. She came up with the concept, the rough design and the placement. My job was to make it happen, hauling dirt and logs around, hoping it lived up to her vision. If it failed, it was flawed design. If it worked, it was because of my commitment and hard work. Win-win! (right?).
Last weekend we had a window of opportunity. Grandparents were visiting so kid wrangling was taken care of. My brother in law (a 20 something year old who keeps very fit) was also present to help out. It was almost too convenient….
Now, a sandpit requires 2 things: Sand and a pit. Actually that’s not quite true. They can be above ground; a clam-shell-pool, a set of timber sleepers, a circle of stones whatever…. So to revise, a sandpit requires 2 things: Sand and something to contain the sand.
Our design met these strict conditions, and I thought it was worth sharing because honestly it was so bloody easy to build something that I wanted to let other aspiring sand-pit artificers know that it isn’t all that hard. Our plan was simple: Dig a hole, surround it with a retaining wall made of leftover timber from our massive gum trees tyres, add a drainage layer and then fill it with sand.
- Sand (duh)
- Old tires
- Old carpet
- Redgum logs
Phase 1: Marking Out
Using star pickets and the pieces of timber/tire that would become the retaining wall we marked out the space for our sandpit. If making a retaining wall out of “found objects” like us, all you need to do is arrange them around the space your digging slightly back from where they will sit. Once the pit is dug you can push them into final position.
Phase 2: Digging.
The ground around our house is full of chipped quartz and gravel. Digging through it was difficult, it had to be broken up with a mattock first and then dug out. Fortunately my brawny brother-in-law Uncle D was on hand. I recommend everyone gets a brawny brother-in-law to help with this phase, they make it much easier.
We dug to a depth of about 15 cm, but we didn’t care too much exactly how deep, and we didn’t care about how level it was. It’s a sand pit not a floor, so it really doesn’t matter. The softer your soil the easier it will be! IF you’re digging into softer soil you might get away with not using a mattock. We certainly couldn’t.
The dirt was retained to shore up our retaining wall and fill the tires we used as part of the wall to make sure things stayed put.
Phase 3: Drainage layer.
A sandpit needs a layer between the dirt and the sand. Well, in fact it doesn’t, but it’s a good idea to have one because it keeps the sand sandy and the dirt dirty, if that makes sense. We wanted to build something that would drain well. In spite of our best intentions we were sure we’d forget to cover the sandpit on occasion, so drainage would be desirable
Our solution was to put in a layer of Scoria (volcanic rock) and then cover it with old carpet before putting the sand in. This did a few things: It let us level the bottom of the sandpit easily, made sure that would pass through the sand but the soil would remain out of it and it created a gap full of air pockets and a porous rock which would ensure water would flow down out of the sand if it got wet. We used carpet because we had some lying around, but really any material could do it. Heshian, shade-cloth… Whatever you’ve got lying around. The scoria layer is not 100% necessary, especially if your soil already drains well, but we wanted to make sure the pit could drain quickly and well if it needed to.
Phase 4: Reinforce!
A retaining wall made out of heavy eucalypt stumps needs to be solid and secure. I want my kid’s to climb over the logs and stumps, play balancing games and jump off them into the sand. So I don’t want the wobbling or moving too much. Using some of the left over dirt from digging out the pit I went around and built up soil around the base of each log, knowing that it will need to be re-done regularly.
Phase 4: Something is missing… oh yeah….. SAND!!!!
So we had a hole in the ground. Just add sand! Now if I have one major piece of advice, this is it: If you are putting any big-ish amount of sand into a sand pit for god’s sake don’t buy it in bags. Get a trailer (or hire one), find a land-scape supplier and get sand pit sand from them. It is SO MUCH CHEAPER OH MY GOD. “Sand pit sand” from Bunnings will set you back $7.90 for 20kg. This sounds like a lot, but is really stuff all. A trailer load (1/2 a cubic metre) – set us back 50 bucks. The equivalent cost in bags would be about $300…. Given we need to get a second trailer load in, it adds up quickly.