How To Make Concrete
So for today’s blog post, we’re going to make a concrete path. It wants to be between 75-100mm thick so it’s strong. It’s going to be so awesome!
First, lay the boxing out. Set the boxing with wooden edges marking out the edge of the concrete. Make sure its level, if you don’t have a level you can download a leveling app on your iPhone. Put pegs in to hold the boxing – probably don’t use nails because you want to take it off later, its only temporary! The thinner the boxing, the more pegs you need to put in. So use strong wood that won’t bend easily.
Put down some wire mesh down the bottom for long-term strength and durability. Prop it up off the ground with some rocks or something – we used broken pottery because it was lying around – the wire mesh should be off the ground for the most part, but not poking out above the boxing.
Take any rubbish out of the area – a few weeds won’t matter, but keep it to a minimum.
Mixing the Concrete
Making concrete is just like making pikelets – it’s just another recipe!
- 1 shovel of cement
- Half a bucket of water
- 7 shovels of builder’s mix (sand & stones)
When it’s wet, cement chemically reacts with itself and starts binding. It drives the water out and generates heat.
Shovel the cement and builders mix into the concrete mixer along with the water, and empty the contents into the wheelbarrow.
Empty the wheelbarrow onto the area where you want the concrete and rake it into a corner.
Screeding & Floating Off
Starting at one end, start screeding it with a plank of wood that is longer than the width of the boxing. You’re basically planing it off.
When screeding, jiggle the screed up and down to get rid of air bubbles and jiggle from side to side to let the stones sink down. Slide it along the boxing to give a flat finish. You always want a little bit of concrete leftover because too much is better than not enough! You don’t want to run out and have a gap.
if there’s a slope, use boxing with smooth and solid timber down the bottom end so that it doesn’t have an ugly side after the boxing is taken away. Also when you’re screeding, make sure all the air pockets are gone so the concrete fills the entire face of the boxing. Otherwise, when you remove the boxing, you will have to plaster it up to hide the ugly gaps.
Once you’ve screeded it all, float it off by sliding the float – slightly raised – over the wet concrete. Smooth it off and come back again later when it’s drier. Repeat this process 2-3 times until you can’t anymore because its too dry.
Be sure to wash the concrete mixer thoroughly and all your tools by hosing them down, or you’ll never be able to use them again! Have you ever made oat porridge and not washed the pot, only to find it very difficult to clean the pot the next day? Yeah, concrete is 100 times worse than that, you will ruin your tools. Don’t be that guy. Wash your tools.
Finally, when its dry and you’ve taken the boxing off, round the edges of the concrete so that they’re not sharp and ugly.