Tips for a Durable Concrete Slab for Your Backyard Shed

A sturdy foundation is not just a luxury but a necessity, especially when it comes to enduring the coastal climate of Frankston. Known for its beautiful beaches and coastal charm, Frankston attracts residents who appreciate the blend of natural beauty and practical coastal living. Whether you’re storing tools, setting up a workshop, or creating a space for relaxation, your backyard shed is an essential extension of your home in this vibrant community. Ensuring it stands the test of time begins with a solid foundation—a concrete slab specifically designed to withstand Frankston’s unique environmental conditions.

concrete shed slabs

Why a Concrete Slab is Essential for Your Shed

In Frankston’s coastal climate, where salty air and occasional storms are common, the importance of a sturdy foundation for your shed cannot be overstated. Opting for a concrete slab is crucial, offering unmatched durability and resistance to corrosion from saltwater. Unlike timber foundations that may deteriorate over time, a concrete slab provides a stable and secure base that ensures your shed remains resilient against the elements for years to come.

concrete shed slab foundation

Steps for Building a Concrete Slab Foundation

Building a concrete slab foundation for your shed requires careful planning and execution. These are the essential steps to ensure a sturdy and durable foundation that withstands the test of time:

Site Preparation


Start by digging a hole that’s the right size for your shed. Make sure it’s deep enough, usually about 10-15 centimetres, depending on how big your shed is. This hole isn’t just for the concrete – it also lets water drain away properly when it rains, which helps keep your foundation strong and stable.


To make your concrete slab strong and sturdy, you need to reinforce it. Use materials like metal bars (rebar) and wire mesh to prevent it from cracking. Lay the rebar in a grid pattern in the hole, covering it with wire mesh. This makes sure the concrete can support the weight of your shed and anything you put inside it, keeping it strong and safe for years to come.


Building a frame is important to shape your concrete slab. You usually use wooden boards for this. Make sure to stake them firmly into the ground to keep them in place when you pour the concrete. Keeping the frame level is crucial so your slab doesn’t end up uneven. This gives you a solid and even base for your shed.

Pouring the Concrete Slab

Mixing and Pouring

Getting the right mix of concrete is key to making a strong and durable slab. You can mix it up yourself or buy it ready-made like this one from Bunnings. Pour the concrete into the framed area, starting at one end and moving to the other, making sure it spreads out evenly. Use a shovel or rake to spread it out and get rid of any air bubbles trapped inside.

Levelling and Smoothing

To make sure the surface is flat, use a long, straight board called a screed. Drag it across the top of the concrete to even things out. Then, use a trowel to smooth it all out. This step is really important because it makes the slab look good and work well too.

Finishing the Concrete Slab

Finishing Techniques

When it comes to finishing your concrete slab, you have a few options. You can choose a brushed finish for better grip, especially when it’s wet outside. To do this, gently sweep a broom over the wet concrete surface. If you prefer a smooth finish, use a trowel to make it nice and even.

Curing Process

After you’ve finished working on the concrete slab, it’s important to let it cure properly. This means covering it with a plastic sheet or damp hessian to keep it moist. Leave it like this for about a week to make sure it sets well. Don’t put anything heavy on it for at least 28 days to give it enough time to fully harden and become strong.

thickness of slab

Common Questions and Concerns

Understanding the key aspects of your concrete slab’s thickness, reinforcement, and curing process is crucial for a successful shed foundation. Here’s what you need to know:

Thickness of the Slab

Determining the right thickness for your concrete slab is crucial for its durability and stability. Typically, a thickness of 10 centimetres is recommended for a backyard shed. However, if you have a larger or heavier shed, you may need to opt for a thicker slab, around 15 centimetres. Factors like the type of soil and the weight the slab will bear influence the required thickness, so it’s essential to consider these factors when planning your project.

Reinforcement Details

Reinforcing your concrete slab is vital to prevent cracks and ensure its strength. When placing reinforcement, such as rebar and wire mesh, it’s important to follow a grid pattern and space them approximately 30 cm apart. Position the wire mesh over the rebar for added support. Ensuring that the reinforcement is centred within the slab maximises its ability to provide support and durability over time.

Curing Time and Process

Allowing the concrete slab to properly cure is essential for achieving its full strength. Typically, it’s recommended to let the slab cure for at least 28 days. Signs of proper curing include a hard, dry surface without any visible cracks. Rushing the curing process can lead to cracks and diminish the strength of the concrete, so it’s important to be patient and allow adequate time for the slab to cure thoroughly.

These considerations are not exclusive to shed slabs but are also relevant to various concrete projects. Whether you’re renovating your driveway, installing a patio, or building a shed foundation, understanding the key aspects of concrete thickness, reinforcement, and curing process is crucial. 



Investing time and effort in a proper concrete slab foundation will pay off in the long run, ensuring your backyard shed remains stable and durable for years to come. By following the steps outlined in this guide, you can achieve a solid foundation that will support your shed and withstand the elements. However, for those who prefer to entrust the task to professionals, hiring a skilled concreter can provide peace of mind and expert results. Ready to start your shed project with a solid foundation? Contact us today to discuss your concrete slab needs. Our experienced team is here to provide expert advice and quality service tailored to your project requirements. Explore more tips and insights on concreting shed slabs and other home improvement projects by visiting our article page. Let’s build something exceptional for your backyard!

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About Us

With over 30 years experience in the concreting industry, owner-operator Gary provides quality residential and small scale commercial concreting services in Frankston, the Peninsula and Melbourne’s South East. We pride ourselves in providing well built concrete structures with good old fashion caring customer service all at a competitive price. Call today for a free onsite measure and quote.

(03) 9000 0676

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