How Thick Should Concrete Slabs Be To Survive Australia?

How Thick Should Concrete Slabs Be To Survive Australia?

Australia is fronted with some of the harshest conditions on the planet. Sun, wind, rain, snow, salt and everything in between, we have it all. Anything exposed to the Australian elements is at high-risk of deteriorating. We don’t get nicknamed “the sunburnt country” for no reason. 

As such, it is important that we in Australia build our things to last. You might not think about it, but this also applies to your concrete work. The way you use and build with concrete needs to be strategically engineered to last in the Australian condition. You want to make your concrete slabs thin enough to be cost-effective, but thick enough that they will not break. Here is what your concrete slab thickness by Australian standards should be, to give them the best chance to survive. 


Concrete Slabs – The Basics 

When you are building with concrete slabs, a general rule of thumb is the thickness is around 10cm or 4 inches. This should be the minimum thickness of your concrete slab. The harshness of the sun and expansion from the heat will make thinner pieces crack and break. Concrete expansion joints are another way to bolster the resilience of your concrete slabs. 

When working with concrete slabs, there are 3 elements that will need to be perfected, to improve its strength: 

  • Base preparation – what is under the concrete 
  • Mix design – the consistency/quality of cement and its thickness 
  • Curing – how its dried and sealed 


How Thick Does Concrete Slab Need To Be For A Shed?

If you were ever going to try and get away with having a slightly thinner concrete slab and save a bit of coin, not that we would recommend it, it would be a slab for a shed. Why is this the case? Well a shed is undercover, which means the concrete slab floor is protected from the sun. It also doesn’t see too much foot traffic, and doesn’t have heavy cars driving on top of it. 

However, you will be using heavy tools on top of it. If you build your concrete slab floor too thin, the slab is likely to break if you accidentally drop anything on top of it.

Because of this, we recommend that you build your shed’s concrete slab between 7.5cm to 10cm, ushering closer towards the side of 10cm.


Be Careful When Building A Shed Yourself

When building a shed yourself, you need to make sure that you seek council approval first. If you are still not sure after you ask the council for permission for your new shed, you should hire a professional. 


How Thick Does Concrete Slab Need To Be For A Garage/Driveway?

Concrete slab thickness for a garage, or the minimum thickness of a concrete driveway, needs to be significant. Not only will the driveway be in the sun and exposed to the elements, it will have tonnes of cars and other garage play toys trudging over it. The wear and tear of a concrete slab used for a driveway or garage is extreme. Garage and driveway concrete thickness needs to be taken seriously. 

As such, when you’re building your garage, we suggest that the absolute minimum concrete slab thickness should be 20cm. 


Regulations For Building A Garage

Just like building your shed and paving that area, before you start working on your garage, you need to get council approval. Additionally, your garage build might have a value of more than $20,000. If it does, it will be classified as building work and you will need a registered builder. If you are unsure if you need a registered builder or what the  concrete driveway thickness standards are, you can get some answers here.


How Thick Does Concrete Slab Need To Be For A Patio/Path?

Patio concrete thickness and concrete path thickness is more versatile than other uses. If you are paving a small area with a single table and two chairs, no doubt this can be a thinner piece of concrete than if it was used for a full fledged outdoor living space, complete with luxury table, fridge for the frothies and the entire kitchen sink. Also, if you’re expecting the people you will be hosting on your space to be a little boisterous after a few too many glasses of semillon-sauvignon blanc, maybe a little bit of a thicker slab would be better to accommodate their rock-stomping feet.

Depending on what sort of outdoor space you are building, we would recommend having your slab thickness between 7.5cm to 12.5cm. 


Patio Planning and Regulations

Once again, if you are planning to build a patio, you need to get approval from your local council. Even if it is a very small modification, it is better to ask and be reassured than to find out later you’ve just wasted your time and money because your build was not regulation. Hiring professionals will also give you this peace of mind, particularly if any concrete drilling or cutting needs to be made for plumbing and gas.


How Thick Does Concrete Slab Need To Be For A House?

Feeling particularly ambitious, are we? We commend the effort if you are attempting to lay slab and build your own house. Concrete slab thickness for a house should be strong and thick because it will give you a good foundation to build on. 

It is suggested that your concrete slab for your house should be 15cm thick.


Building A House Regulations 

It’s probably pretty obvious by now, but if you’re building a house, you probably need to seek permission from your local council. You are also going to need a registered builder to do part of the building work. Your concrete slab is very important, it is the foundation for your house. You should not neglect its importance and hire a professional. 


Final Comments On Your Concrete Slab Thickness

As a last piece of advice, your concrete slab thickness should ball park from between 7.5cm minimum concrete thickness on lighter jobs, to 20cm for heavy duty areas. Usually, we would not go anywhere lower than 10cm, but you can get away with it. 

Diamond Cut Concrete provides some of the best solutions for concrete in Perth. This is because Diamond Cut Concrete offers a 24 hour customer service line and can provide you with a quote within a day. We have completed close to 1,000 successful projects and have a 100% clean safety record. For any concrete project solutions, contact us today!

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