Concrete has a lot going for it – unparalleled strength, longevity, and durability in every environment. Doesn’t burn, rust or rot. And it’s versatile – something that can be used in all kinds of DIY projects.
Yet it’s not too hard to make up yourself. All you have to do is mix the right combination of ingredients, namely cement, sand, and aggregates.
Meanwhile, ready-mixed concrete can cost up to about £85 per cubic meter. If you’re a DIY enthusiast, we can imagine how you might want to make your own mix. And in some instances, that’s totally fine, but there will be occasions when it’s more appropriate to simply buy a few packs of ready-mix.
In this article, we’re going to look at the different factors that can influence when it’s better to mix your own, or to buy a ready-mix.
Project Time Frame
Mixing concrete by hand is much more time consuming than you might think. And the bigger the project, the longer this will take.
So if you’re in a rush to get the project over and done with, or if there’s a particular urgency for the project, then you might well enjoy the convenience of having ready mixed concrete arrive at your door.
If you have the opportunity to work at your own pace, however, and you want to mix your own concrete, then we recommend that you calculate how long it takes you to mix one cubic metre’s worth of concrete, so you can estimate how long it will take to make all the concrete required for your project.
Applying in Batches
When you’re mixing concrete by hand, you will need to apply each batch straight away, particularly if you’re using a quick setting combination.
But the trouble with this method is that when you’re mixing concrete in batches, there’s a clear time gap between each batch being applied. And the issue with that is that as earlier batches are just starting to set, the wetter mix being applied fresh results in the creation of a weaker structure.
In many instances, this may not necessarily be a problem. However, if you’re attempting to build any kind of load bearing structure, such as a driveway or a shed base, then this would be an issue.
No matter how fast you hand mix your concrete, there will always be batches that are lightly drier or wetter than others, so you risk having a real inconsistency in the concrete, that can mean you get a structural weakness.
If, by the end of the project, the concrete will be visible to the eye, then you should aim for a nice finish.
But again, if you are mixing your concrete by hand and applying in batches, then you will get problems in consistency that will markedly affect the overall finish.
If you were instead to use a ready mix, and apply the concrete by pouring it all at once, then you can avoid an uneven finish altogether, as it will all dry and set at the same point.
Some projects using concrete require the concrete to be air entrained, meaning that it features tiny air bubbles in the mix. This is because the air bubbles can help protect against weathering in cold and wet weather.
However, in order to be sufficiently effective, these air bubbles need to be completely uniform throughout the mix. And such a feat is almost impossible to achieve when mixing your own concrete, whereas with a ready-mix this is already taken care of.
As we mentioned in our introduction, you also need to consider the comparative costs.
Although not having to buy ready-mix, may at first make hand mixing sound a far more affordable alternative, you will have to pay money for the component parts, and need several bags of cement.
So what you need to do is directly compare the cost of ready-mix against the total cost, of not just the individual cement bags, but also any additional costs that the project may require. This might include mixer hire, tool hire, and so on.
You also need to consider the costs of any lost wages, if you have to take time off to complete the project.
Once you have established just how much concrete will be needed, you might feel that by mixing by hand, you can minimize waste, and get closer to the exact amount of concrete required.
This is a fair jugement to make, and you can certainly see the logic to it. Why purchase a cubic meter of ready mix concrete when you only need half a cubic meter’s worth?
However, it is certainly worth noting at this point that some ready mix concrete suppliers offer a service whereby they take away wasted concrete mix, and sometimes they do this completely free of charge.
You will need to assess whether you can adequately get a concrete mixer to the site of the project. For example, would parking sufficiently close be possible?
If a concrete mixer cannot be transported to the project site, then it may be necessary to use a wheelbarrow in it’s place. But this of course is not ideal.
So, as you can see, there are a number of different factors that can influence your decision about whether it’s best to mix your own concrete or buy a ready-mix.
If the project requires only a very small amount of concrete, then making your own concrete can lead to savings in both money and in reduced wastage.
If however the project you have in mind will be load bearing, require a perfect finish, or require uniform air bubbles to combat weathering in cold weather, then your best option may be to simply go ahead and buy ready-mix concrete, and save yourself some time and effort.
We trust that this article has armed you with the knowledge you need to make the best possible decision.