Ready-mix concrete is a hard wearing, durable and versatile material with a wide variety of applications. In a domestic setting, some of its most common uses are in laying a patio or driveway, or as foundations for a home extension.
If you’re a competent amateur with some experience of larger scale DIY and construction work, you might be tempted to attempt one of these projects by yourself. All of them are relatively straightforward projects for experienced professionals, but they do present a number of possible pitfalls.
Driveways are one of the most popular uses of ready-mix concrete. If it’s done properly, a concrete driveway will be attractive, hard wearing and strong enough to cope with whatever is thrown at it.
It often comes as a surprise to people that you might need planning permission for a concrete driveway. It depends on the type of concrete you’ll be using. If you’re using porous concrete, you won’t need planning permission. If you’re looking to use non-porous concrete however, it’s likely you’ll need planning permission. If you haven’t obtained planning permission and choose the wrong kind of concrete, it’s possible that your new driveway will have to be removed.
Get the dimensions right
Once you’ve decided on the dimensions you need to stick to them. You should order the correct quantity for these dimensions, being careful not to change your plans at the last minute. This will ensure that the strength and functionality of your driveway isn’t compromised.
Layout the perimeter of your driveway
Outline the perimeter of your driveway with wooden stakes. These should be spaced at regular intervals being careful to ensure that the final outline properly matches your dimensions. You should then use wooden planks to create a solid, temporary housing for the driveway. These wooden forms should be strong and secure enough to keep the concrete in place while the concrete is poured. The planks should be anchored to ensure that they remain straight and aligned.
Dig out the topsoil and ensure the sub-base is level
A driveway needs a strong, solid sub-base, so the topsoil should be dug out to the required depth. If the sub-base is not suitable for laying a driveway, you’ll need to dig it out further and then add hardcore. It should be well-compacted with hardcore of at least 100mm in depth. This will provide a solid base for the concrete to be poured on. Get this stage wrong and cracks and other problems are likely to occur.
Reinforce with steel
Not every driveway needs it, but to add extra strength a driveway can be reinforced with steel. This can be done by inserting steel wire mesh in a grid pattern into your pour site on top of the sub-base. This will help to distribute the weight of any vehicle more evenly, considerably improving the overall strength of the driveway.
Pour the concrete
With the sub-base and perimeter in place, it’s now ready for the ready-mix concrete to be poured. The concrete should be poured in even loads, and as you do so you can distribute the concrete through the form using a hoe. You should aim to keep the concrete relatively flat, and slightly higher than the form.
Flatten and smooth out the surface
Once the concrete has been poured the surface should be smoothed out and flattened to create a consistent surface. This can be done using a straight piece of timber, moving it steadily backwards and forwards in a steady motion to help flatten out the surface.
Add contraction joints
Contraction joints help to control the expansion and contraction of a concrete slab as it dries. These are created using a concrete grooving tool and should be placed at regular intervals to a depth of around 25mm.
Create a non-slip finish
A driveway should be non-slip when a vehicle moves onto it. Moving in one direction, use a strong bristled broom to give the concrete a textured finish.
Cure the concrete
A driveway should be water cured for 7-10 days after the concrete has been laid. This is done by regular spraying using a sprinkler, by laying down wet curing blankets or a layer of plastic sheeting. This will create a moisture retaining barrier and will ensure the driveway is strong enough to bear the weight of any vehicle.
Remove the forms
Once curing has begun and the concrete is properly hardened it should be safe to carefully remove the forms. Take your time, and if you see any sign that the slab is not yet fully hard, stop and carefully replace any part of the structure you’ve removed.
Despite being a common domestic use of concrete and relatively straightforward, the process of laying a driveway needs to be done correctly if expensive repair work is to be avoided. A professional will know the process, what potential problems to look out for and how to ensure the end-result is as good as it can be given the location.