Building your own concrete path is a very rewarding and good project to make. Not only you know it was build properly, you are building something that will last for a very long time.
When I realized that I need a path for my back yard, I knew that it'll be from concrete and that i'll build it myself. Looking around the web for ideas I stumbled upon these concrete plastic molds. Not happy with the shape and flimsy look of them, I decided to build a better, stronger one myself.
This instructable involves 2 skills: welding and concrete pouring. No need to master these 2 but you do need to have some basic skills in knowing how to mix concrete and how to weld to accomplish this project.
Step 1: List of Materials
- 2400 mm X 40 mm X 2 mm flat steel bar cut into 600 mm strips
- 2000~2500 mm of 10 mm X 10 mm square steel profile
- Concrete mix (concrete, sand, fine gravel, water)
- Some string
- Metal peg
- The usual assortment of tools
Step 2: Making the Mold
To prepare the mold i welded 4 pieces of 600mm X 40mm to make a square. Made sure it was squared perfectly. I welded it from the outside to make sure that when i set the concrete i will have perfect corners.
The pattern (10X10mm square profile) was something i drew off my head and then I transferred it to the frame. Here you can just let your imagination run and make really nice patterns.
The pattern was welded from the top by a strong tack weld. (Anything else will warp the whole pattern and make a hole that you can't recover from... besides, this doesn't need to support a bridge...)
To aide me in squaring and holding the pieces while welding I used a 90 degree cast iron clamp. It'll be extremely hard to do it any other way (unless you have a special welders prep table)...
Step 3: Preparing the Ground
This part is the most important since it will determine the outcome of this whole project.
The ground has to be fairly leveled, make sure you mark with a string the intended path to make sure you are aligned and not drifting like it happened to me. I ended up tearing up the first 3 slabs i made because i wasn't aligned.
Check and check again. make sure you're aligned perfectly. Level the string, check it every time you pour a new slab.
Step 4: Pouring the Slabs
Placing the mold for the first pour is very important. level it and check it several times. I used small pebbles to fine tune my alignment of the mold. After i made sure that the mold is leveled and stable I started mixing the concrete.
For my mold i used 5kg concrete, 15kg sand, 5~10kg fine gravel. The amount of concrete that you'll get\need for one slab varies on your mold size. Experiment...
You'll notice that i haven't used plastic or polypropylene on the ground before pouring. Instead, I sprayed it with water so the poured concrete will not dry too fast.
I didn't take pictures of the pouring itself but it's basically the same as any other pouring process in which you flatten the the slab and then tap all around the mold to make sure there are no air pockets. After a few minutes i slowly take out the mold. This is the place to mention that the concrete mix has to have the right consistency so it does not sag or goes splat all over the place, think of a thick porridge consistency for the concrete.
Step 5: Finished Results
Since this was my first time laying a concrete path, I did some mistakes and had to do 3 slab all over again... but, i learnt how to do it right and fast.
You'll need to water the new path with water for a whole week to make sure the concrete hardens properly.
This path is 10 meter long. it took me some time to make but that was due to unforeseen holdups...
If I would have done it with no interruptions, i'd finish it in 2~3 days.
Thanks for taking the time reading this instructable. This is a bit more advanced from my other ones but someone with 2 good hands and straight thinking (wait, isn't that all makers? :-) would probably breeze through this...
P.S.: Please vote for me in the Concrete & Casting Contest. Thanks!