Planning your job

Measuring is an important part of the preparation process. Use a string line and chalk to mark out the area you want to concrete, and use a spirit level to ensure your job is finished perfectly level and even.

Use our Concrete Calculator to help estimate the amount of concrete you need.

Please make sure you add 10% on to the final calculation to ensure you cover any errors in your estimations.

Concrete can be provided in several different MPA’s (megapascals). This dictates the mix of concrete, sand and water to ensure your concrete is the correct strength. For most domestic jobs 25MPA is suitable, and for more industrial or heavy traffic areas 35MPS is available. If your slab needs to support a lot of weight or traffic, you might consider using steel mesh ‘reo’ to increase the strength of your slab.

Site Preparation

Dig out the site evenly, remove any tree roots. A layer of crushed rock will make the slab stronger, especially if the soil is soft. Reinforcement can also be used to strengthen a concrete slab which is going to be supporting heavy weight.

Formwork

Ensure that you are using formwork that is thick enough to support the weight of wet concrete pushing against it.

Formwork should be the height of the slab thickness. This makes it easier to level the top of the concrete to the top of the formwork.

Formwork should be removed 24 hours after the concrete has been poured.

Weather

Concrete can be poured in temperatures from 10°C to 35°C. Earlier in the day is better because it is cooler, the air is more humid and there is less wind speed.

During hot weather soaking the site with water prior to pouring concrete will help minimise moisture loss.

Ordering Concrete

If you order your concrete several days in advance, Eastern Premix can guarantee delivery on the day and time that suits you.

Ensure the truck has unrestricted access to the site in the current weather. This ensures that the truck can deliver the concrete right to the slab location. Also make sure there are wheelbarrows ready to go to avoid any delays and ensure your concrete is laid while it is fresh from the mixer.

Eastern Premix has a range of concreting tools and safety equipment that can help to ensure a professional result.

Curing

Most slabs cure in 3-7 days. It is critical that the slab be kept moist to allow it to harden slowly. This can be done by hosing the slab with a light mist several times a day for 7 days. You may also put plastic over the slab to hold in moisture.

 

The slab can be walked on after 3 days, and can be driven over after 7.