That's basically it! You don't really need much water either. It just kind of looks like dirt coloured concrete. Technically you only need about 10-15% cement to soil. But since I was raising the level and and adding topsoil (also being lazy), I didn't measure it and just used a whole bag of cement. Tamped it to level it out, but it isn't perfect as I'm going to use some paving sand and pavers to level out the top of it anyway.

If you don't mind a 16 minute video, this what I watched before deciding to try it: https://youtu.be/tNoWVPVb6Mo

[–] Dave@lemmy.nz 2 points 1 day ago (1 children)

Interesting, I skimmed the video to see the important bits. Their one is in ground, and I notice towards the end of the video they are showing the chunks being quite brittle, which probably isn't an issue when it's in the ground. You mentioned it needs to be higher than the ground level so the door can open, do you have an edge to it or are you risking having the edges crumble?

[–] eagleeyedtiger@lemmy.nz 2 points 1 day ago* (last edited 1 day ago) (1 children)

You got caught out by skimming the video 😝

He says he underestimated thinking that experimental piece with a higher ratio would be fully hardened in 3 days.

Concrete/cement usually takes weeks to months to fully cure to it's full strength. In any case the lower side of mine has an edge and I've actually made it slightly larger than I need. I think it should be OK, It's not like it's going to have cars or foot traffic on it just mainly storing things.

I think I will get some crumbling at the edges as it was hard to mix there. I've removed the wooden form I used and it's holding together for now.

[–] Dave@lemmy.nz 2 points 1 day ago (1 children)

Ah haha I guess I didn't see all the important bits 😅

It makes sense it would be harder to mix at the edges, hopefully it does the job anyway.

[–] eagleeyedtiger@lemmy.nz 2 points 1 day ago (1 children)

My plan is to have things on either side of it, so maybe I'll back fill the gaps with gravel or put some bricks around it to help it out just in case. 😅

[–] Dave@lemmy.nz 2 points 1 day ago

Not a bad idea. I guess it depends on how the ground is shaped around it, you don't want chunks falling off when you clip it with the mower trying to mow the grass at the edge. But you tell me it won't be that brittle so maybe it will be fine once cured 🙂