The concrete floor is an important part of any shed, but the finish is often treated as an afterthought.
The right concrete finish depends on how the shed will be used. A farm machinery shed may only need a durable, practical surface. In contrast, a workshop or high-end lifestyle shed may benefit from an easier-to-clean or more visually appealing floor finish.
The main options are a standard trowel finish, polished concrete, exposed aggregate, and epoxy paint. Each has a different appearance, level of durability, maintenance requirement and cost.
It is also important to understand that the floor finish is only one part of the overall concrete price. Slab thickness, reinforcing, site access, excavation, ground conditions, and the amount of preparation required can all have a much larger impact on the final cost.
In this article, we explain the main concrete finishes available for kitset shed floors, where each option works best, and the typical cost differences you can expect.
A trowel finish is the standard and most cost-effective option for most shed floors.
Once the concrete has been poured and levelled, the surface is worked with hand or powered trowels to create a smooth finish. The final appearance is generally plain grey concrete, although some colour variation should be expected.
A trowel finish is suitable for most practical shed applications, including:
It provides a hard-wearing surface that can handle vehicles, machinery and general day-to-day use. It is also relatively easy to sweep and clean compared with a rougher concrete finish.
The main limitation is appearance. A standard trowel finish is functional rather than decorative. It may also show oil stains, tyre marks and general wear over time, particularly in workshops or high-traffic areas.
A very smooth trowel finish can become slippery when wet. In areas where water is likely to be present, such as washdown bays or around entrances, a slightly more textured finish may be more appropriate.
A standard trowel finish is normally included as part of the concrete slab price rather than charged as a separate upgrade. A standard 100mm thick concrete floor with 668 reinforcing mesh and a polythene underlay will typically cost about $110.00+GST per square meter (excluding siteworks such as site cuts, levelling and a compacted gravel base).
For most working sheds, a standard trowel finish offers the best balance of durability, practicality and cost.
Polished concrete is mechanically ground and polished to create a very smooth finish. It is commonly used in lifestyle sheds, showrooms, garages, and workshops where appearance and ease of cleaning are important.
Polished concrete looks more finished than standard concrete and is durable, but it can show scratches, oil stains and tyre marks. It may also become slippery when wet.
Polished concrete generally costs from around $100 per square metre on top of the slab cost, depending on the level of polish. Polishing the slab increases labour as it takes a lot longer to finish, which is where most of the additional cost comes from.
Exposed aggregate is created by using an acid wash to remove the top layer of concrete to reveal the decorative stones within the mix. It provides a decorative, aesthetically pleasing finish that provides excellent grip.
It is usually better suited to areas outside the shed, such as entrances, aprons, paths and washdown areas, rather than the main internal floor. The rougher surface can be harder to sweep and clean.
Exposed aggregate typically adds around $30 to $70 per square metre compared with a standard concrete finish, depending on the aggregate selected.
It's important to note that this exposed aggregate finish can also be highly polished for indoor areas. The difference is that the acid wash is not required; however, the surface is ground down using diamond-tipped grinding plates. This removes the top layer, exposes the decorative aggregate inside the concrete and leaves a highly polished finish. This finish is typically used inside and looks very nice. It does become highly slippery when wet, as it is a very smooth finish.
Epoxy paint is a commonly used option that creates a sealed, durable surface that is easier to clean than bare concrete. It is commonly used in workshops, garages, commercial sheds and areas where oil, grease or chemicals may be present.
It is available in a range of colours and can include a slip-resistant additive. However, the concrete must be properly prepared before application, or the coating may peel or fail.
Epoxy flooring generally costs around $50 to $120 per square metre in addition to the standard floor cost, depending on the preparation required and how many coats of paint you add.
For most working sheds, a standard trowel finish is the most practical and cost-effective choice.
Polished concrete suits sheds where appearance matters. Exposed aggregate is generally better for outdoor areas, while epoxy is useful in workshops and garages where easier cleaning and stain resistance are important.
The best option will depend on how the shed will be used, your budget, and the level of maintenance you are comfortable with. Before pouring the slab, discuss the intended finish with your concrete contractor or with the Alpine team.