TuffBlock Deck Block vs Concrete Slab - Which is better for sheds?

shed subframe layout joist using TuffBlock

When it comes to constructing the perfect foundation for your shed, the decision can be a daunting one. After all, the foundation is the literal groundwork upon which your entire shed will stand, so making the right choice is crucial. While traditional concrete slabs have been the go-to option for decades, a new contender has emerged in recent years: TuffBlocks. These innovative foundation blocks have sparked a debate among DIY enthusiasts and homeowners alike, as they offer an alternative to the tried-and-true concrete approach. So, which path should you choose on your shed-building journey?

concrete slab

In this blog post, we'll explore the key factors to consider when deciding between TuffBlocks and a concrete slab for your shed foundation, helping you make an informed choice that best suits your needs and preferences. Whether you're a seasoned DIYer or a first-time shed builder, this guide will provide valuable insights to set you on the right path. Let's dive in and uncover the pros and cons of each foundation option, so you can embark on your project with confidence and clarity.


shed build using TuffBlock

Using Rodney’s 65sq meter shed as an example

Rodney built this awesome shed using TuffBlock as a foundation instead of a concrete slab, so we thought we’d explore his build and weigh up some of the benefits of choosing TuffBlock:

shed subframe layout using TuffBlock
joist layout for shed build using tuffblock
  1. Save time – Concrete slabs require time for the concrete to cure. The form is typically removed after 48 hours, but concrete will continue to harden for 14 days. It’s recommended to let it sit for at least a week before building on it. With TuffBlock there’s no curing period and you can complete a project in a single day.
  2. Save money – For this 20sq m shed, it required 39 TuffBlocks. Depending on materials and layout this could potentially be fewer, but based on this quantity it would cost you around $400 for the TuffBlock foundation. A concrete slab will require the concrete (~$600), rebar (~160), gravel (~500), plus $170 for tool rental (or buying bespoke tools) and finally the lumber to hold it in place (~120). TuffBlocks require gravel under each block, but at a much smaller quantity. In total the cost is going to be roughly $500 vs $1550. Local prices will affect this but the difference is significant.
  3. Work solo – pouring the concrete typically relies on at least 2 people to help pour and then manipulate the concrete to get it smoothed out. With TuffBlock you can work alone without any issues.
  4. Relocate your shed – concrete slabs can’t be relocated, but since TuffBlocks use the floating foundation method you can move it at any time. This is the same for any project using TuffBlock.
  5. Reduce moisture and wicking – over time concrete wicks water. Since TuffBlocks are made from polymer materials they prevent moisture wicking up into the subframe. They also raise the shed slightly off the ground which again reduces moisture buildup.
  6. Easily build on sloping ground – TuffBlocks have 4x4 post slots to adjust for changes in height. Most surfaces you build on won’t be completely flat, and by using checked in posts, you can quickly build a foundation on these types of surfaces. With a slab it’s definitely possible, but sloping ground requires more preparation.
  7. Save tools and materials – concrete slabs require tools & materials that you may not already own. You’ll need a concrete mixer, edger, float, rebar etc. Most builders or DIY enthusiasts will own all the necessary tools for building a subframe, but the tools for building a professional slab aren’t as common.
shed frame

We’d be remiss if we didn’t mention the benefits of a concrete slab so let’s cover that:

  1. Eliminates ground movement: A concrete slab will eliminate any ground movement or settling. Now if you prepare your ground by compacting it down then this shouldn’t be an issue with deck blocks, but there’s no beating a concrete slab in this department.
  2. Even surface: Once it’s built, then it simplifies the building process by constructing on a solid even surface.
  3. Stability and strength for large projects: If you’re building a small house or a mammoth garage/shed then this is suited to a concrete slab. Deck blocks are suited to small/medium sized projects where the benefits of a slab are generally outweighed.


In conclusion, the choice between TuffBlock and a concrete slab for your shed foundation ultimately comes down to your specific needs, preferences, and the unique characteristics of your project. Each option offers its own set of advantages and considerations, as we've explored in this blog post.

If you're looking for a foundation solution that saves you time and money, TuffBlocks present a compelling alternative. With no curing period, the ability to work solo, cost-effectiveness, and the flexibility to relocate your shed, TuffBlocks offer a practical choice for smaller to medium-sized shed projects. They also excel in reducing moisture and wicking, making them suitable for a variety of ground conditions, including sloping terrain.

On the other hand, if you prioritize stability, ground movement prevention, and require an even surface for larger or heavier structures, a concrete slab is the traditional choice that excels in these areas. It offers unmatched strength and durability, making it ideal for substantial projects like large garages or houses.

Ultimately, the decision between TuffBlock and a concrete slab should be guided by your specific project requirements and your budget. Consider the factors that matter most to you, such as cost, ease of installation, mobility, and long-term stability, to make an informed choice that aligns with your shed-building goals. Whether you opt for the innovation of TuffBlocks or the reliability of a concrete slab, both options have their merits, ensuring a solid foundation for your shed.With the mammoth rise in sheds built using TuffBlock we hope it provides you with an alternative that will allow you to build smarter.

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