How to Lay a Concrete Path
Article Summary: How to Lay a Concrete Path or a small area of concrete is a question that crops up on a regular basis in my mail. This is a fairly easy task for those wishing to give it a go. This article will point you in the right direction and ensure your new path is a sure fire success.
You should dig the concrete path site so that you allow a minimum of 3 inches (75mm) of concrete. This will ensure an adequate strength of path. If the path is straight, simply use wood garden edging to form a guide for the concrete to be poured. If you are planning a curved path, first set out the design using a garden hose. This is thick enough to give you nice, smooth corners and bends that you can then use wood garden edging to follow the same contour. Use wood stakes behind and in front if necessary, to keep the edging firmly positioned along the path contour (see below).
As always do some preparatory work to give you best results. Give some consideration not only to where the concrete path is going to go, but also what the final height will be. If you are making a pathway next to a lawn, make sure that the concrete sits at the same height as the lawn. This serves two purposes, one it looks better and two, it makes the lawn edges much easier to cut.
Properly Fix the Wood Edging
More correctly named ‘formwork’, the wood edging needs to be firmly held in place so that the concrete doesn’t escape or knock it down once it is being poured. I once witnessed a very badly built concrete formwork completely destroyed in the early stages of a pour – believe me, it wasn’t a pretty sight!
To get the correct height easily, start by driving in wood pegs at each end of a length of 3 inch (75mm) edging. Make sure that the tops of the pegs are exactly at the height of the concrete path. Next, attach a string line tightly across the tops of the pegs. This will give you an accurate indication of the depth of your excavations. If you have spots where the depth is less than 3 inches (75mm), excavate some more material until the required minimum is obtained.
Once the depth is correct, drive in additional pegs along the line of the string and slightly below the string level at intervals of around 18 inches (450mm). Fix the wood edging by preferably screwing it to the pegs. You can use nails, but be careful that you don’t loosen the pegs with the hammering action. Make sure that the top of the edging is exactly in line with the top of the string line. For curved edging, you can still use the string line. Just make sure that the top of the edging touches the string on more than one point along its length.
Note: If you are excavating soft material, you must dig down until you hit a hardcore base. If it is too deep and you would have to dig out too much, you will have to use a compactor to compact the material until it’s hard and solid. Then use a base material, such as compacted chippings on top to give a good, solid base on which to pour concrete.
Reinforce the Concrete
The chances are that if you don’t reinforce your concrete you will end up with a badly cracked path. The solution is to use a reinforcing mesh. Depending on the size of the path, use mesh supported on ‘chairs’ (available from your local D-I-Y supplier), so that the mesh sits in the center of the concrete. This will add strength to the concrete and help prevent cracking.
In addition to the reinforcement, you also need to add control joints in the path. A control joint is a deliberately added weak spot, or join, in the concrete. Its purpose is to guide any cracks that may appear along its length, thereby making them far less obtrusive than would otherwise be the case. These should be placed at 9ft (3m) intervals.
It really depends on the size of your project as to whether you purchase ready-mixed concrete, or whether you mix it yourself on site. To order concrete, simply multiply the height by width by length. This will give you the amount of concrete in cubic feet or meters. For anything less than 17ft³ (1/2m³) it may be worth mixing yourself if you have a concrete mixer. Your local concrete supplier will be happy to advise you on what quantity and mix you require if you tell them what the concrete will be used for.
Before concrete is poured, check out the weather conditions. Concrete sets by way of a chemical reaction, so wet weather isn’t a problem. What water does do however is pool on the surface of the setting concrete, giving you low spots. That’s why it’s not a good idea to pour while it’s raining.
If it’s a hot day, always wet the surface of the base first. This will ensure that the concrete doesn’t lose all its moisture through the base. The result will be a powdery looking, weak concrete set.
Leveling the concrete after it has been poured is easy because of the formwork. Screed off the surface using a straight edge, using a sawing action to gradually work the concrete between the edgings. Then use a wood or plastic float to smooth the surface further, followed by a final steel trowel to give a smooth finish. Alternatively you may wish to give the concrete a non-slip finish by dragging a hard bristled broom over the surface width. This is a good idea if you live in an area that has regular frosts.
Let the concrete harden slightly, then for a final professional finish, use an edging tool to give a nice, round edge to the path. Not only does this make the path look good, but it helps prevent cracking – cracks seem to start at a sharp edge. Leave the formwork in place for a couple of days while the concrete sets, then before removal tap with a mallet to make sure it comes away easily.