How to Choose the Best Shed Base: Best Shed Base: Concrete, Slabs, Gravel, Plastic Grids & Timber Compared

 

Planning the materials for your garden shed can be a hassle. With so many options, each with various benefits, it’s hard to narrow it down to just one. 

At Atlas Sheds, we are here to run you through the most popular shed base options. We have explored the pros and cons of each to help you make an informed decision.

Browse our range of garden sheds for durable and high-quality structures whilst you’re here.

Key takeaways

• The best shed base for most UK gardens is a level paving slab base or a plastic grid base with gravel, depending on the size and weight of the shed.

• For large sheds, workshops and heavy garden buildings, a concrete shed base is usually the strongest, long-term option. 

• For sloped and uneven ground, ground screws or a raised timber frame may be more practical. 

• You shouldn’t place a shed directly onto grass or soil, as this can cause sinking, damp, rot and poor door alignment.

Shed purpose and requirements

Depending on the primary purpose and size of your shed, certain materials may be more suitable. 

If you are using your shed to store tools and equipment, a durable base is crucial. For a workshop, consider a base that can withstand heavy machinery and foot traffic. 

If you’re creating a garden or office studio, the base must have a level surface and provide good insulation properties. For those installing a greenhouse, this requires a stable, level surface that offers excellent drainage and stability. 

To determine the size of your shed, measure the dimensions and calculate how much base is needed. A heavier shed will require a stronger base to prevent sinking or shifting.

Best Shed Base Options Compared

 

Types of shed bases 

There are various types of shed bases to choose from, with their own range of benefits: 

1. Concrete slab shed base

Concrete is a robust, durable material that can support heavy sheds and resist decay. This requires minimal cleaning and upkeep, perfect for busy schedules and frequent use. 

For those building a workshop or tool storage, this is the perfect option. However, thorough site preparation, including excavation and formwork, is necessary for a concrete base.

This is also an expensive option, making it less suitable for those with a lower budget

Best for: large sheds, workshops, heavy equipment, permanent garden buildings. 

Avoid if: if you want a temporary base or a low-cost DIY option. 

Why choose it: strong, durable, stable and low-maintenance. 

Watch out for: cost, curing time, drainage, removal difficulties. 

2. Paving slab shed base

A paving slab shed base is one of the best shed base options for most small to medium-sized garden sheds. It gives you a solid, level and long-lasting surface without the cost or permanence of a full concrete shed base. 

When laid properly, they spread the shed's weight evenly, help keep the floor off wet soil, and create a stable base that reduces the chance of the shed sinking, leaning, or becoming a problem to open or close. 

But you can’t lay paving slabs straight onto grass or soft soil. For the best results, the ground should be cleared, levelled and compacted first. A sub-base of MOT Type 1 hardcore or similar compacted aggregate should be added before laying the slabs. 

Best for: most small to medium wooden garden sheds. 

Avoid if: the ground is very soft or uneven, unless properly excavated. 

Why choose it: solid, relatively affordable, easier than poured concrete. 

Watch out for: slabs must be laid on a compacted sub-base, not directly onto soil. 

3. Gravel or stone pad

This is a more budget-friendly option compared to concrete or wooden decking. 

Gravel and stone pads provide excellent natural drainage. This prevents water from pooling around your shed by allowing the rainwater to percolate into the ground. Due to this, the risk of rotting, mould formation, and water damage is reduced. 

Relatively easy to install, this option is perfect for DIY projects and supports various shed sizes and weights. However, this isn’t as stable as concrete and requires periodic maintenance to keep the base in good condition. 

Best for: drainage, budget project, use with a timber frame or plastic grid. 

Avoid if: you plan to place the shed directly onto loose gravel without a frame. 

Why choose it: affordable, permeable, good around wet gardens. 

Watch out for: gravel can shift if it’s not contained. 

4. Plastic grids 

For our environmentally conscious customers, plastic grids are the perfect eco-friendly solution for a shed base. 

These are made from recycled materials and include a simple interlock system for DIY installation. Plastic grid systems offer outstanding drainage capabilities, allowing the water to pass through the grid openings into the ground, reducing the risk of mould and rot. 

For larger or heavier sheds, this is the perfect option. Its even distribution of weight reduces sinking or shifting for a stable structure. However, whilst this is cost-efficient due to its durability and low maintenance, the initial price may be more expensive than other options. 

The longevity of your shed will also depend on the materials used for your plastic grid base. 

Best for: quick DIY projects, small to medium sheds, good drainage. 

Avoid if: the shed is very heavy or the ground is not properly levelled. 

Why choose it: free-draining, lightweight, often made from recycled plastic. 

Watch out for: still needs ground preparation and gravel infill. 

5. Raised timber frame

Timber bearers, or a raised timber frame, provide an essential barrier between the shed's structure and the ground by elevating the shed above the surface.

This extends the lifespan of the shed, protecting it from moisture exposure. This is also a budget-friendly alternative to concrete slabs and plastic grids.

For DIY installation, this is an easy, straightforward process. The timber bearers can be adapted to accommodate various sizes and weights of the shed by adjusting the spacing and numbers.

However, this base is more susceptible to rot and insect infestations than others. This means that it requires frequent re-treatment with wood preservatives and replacement of any deteriorated bearer.

Best for: airflow under timber sheds. 

Avoid if: timber is untreated or sits directly on wet ground. 

Why choose it: raises the shed and helps reduce dampness. 

Watch out for: rot, insect damage and future replacement. 

6. Ground Screw Shed Base

A ground screw shed base is a strong and modern alternative to concrete, especially for uneven, sloped or difficult ground. Instead of digging out a large area and pouring a concrete slab, metal ground screws are driven into the soil to give stable support points for a timber or metal frame. 

Ground screws can be good if your garden isn’t perfectly level, as the height of each screw can be adjusted to create a flat platform for the shed. 

One of the biggest advantages of using ground screws is that they allow airflow beneath the shed. This reduces the chance of damp, ideal if you’re installing a wooden garden shed. 

One thing to consider is the final height of the shed. As ground screws raise the building off the ground, they can increase the structure's overall height. This can matter if the shed is close to a boundary or if you have to stay within permitted development height limits. 

Best for: sloped gardens, awkward access, uneven ground. 

Avoid if: you need the cheapest DIY option. 

Why choose it: less excavation, adjustable height, good airflow. 

Watch out for: may need professional installation and can raise the overall building height. 

What makes the best base for a shed? 

• It must be level so doors, windows and roof panels line up properly. 

• It must be solid enough to hold the shed and anything else stored inside. 

• It must have drainage so water doesn’t pool under the floor. 

• It needs to lift the shed away from direct ground moisture. 

• Finally, it needs to suit the shed size, ground type and intended use. 

Can you put a shed directly on grass? 

No, you shouldn’t put a garden shed directly onto grass. Grass and soil hold moisture, become uneven over time and can cause the shed floor to absorb damp. This can lead to rot, mould, insect problems, sinking, leaning and doors that no longer open properly. 

The best base for a shed on grass is a properly prepared foundation, such as paving slabs, a plastic shed base with gravel, a concrete shed base, or a raised timber frame. 

The right choice depends on the size of your shed, how heavy it’ll be when full and how wet or uneven the ground is. 

Which garden shed base is best for your shed? 

• Best shed base for a small shed: plastic grid, paving slabs or compacted gravel with a frame.

• Best shed base for an 8x6 shed: paving slabs or a plastic grid base with gravel.

• Best shed base for a 10x8 shed: paving slabs for standard use; concrete for heavy storage or workshop use.

• Best shed base for a large shed: concrete base or professionally installed ground screws.

• Best shed base for a wooden shed: paving slabs, concrete, plastic grids or raised timber bearers with good airflow.

• Best shed base for wet ground: plastic grid with gravel, raised timber frame, or ground screws.

• Best shed base for uneven ground: ground screws or a raised timber frame.

• Cheapest shed base: gravel or plastic grids, depending on shed size and ground condition.

• Most durable shed base: concrete.

Find the right shed for your garden

Once you’ve chosen the best shed base for your garden, the next step is to find a shed that suits your space, storage needs, and budget. At Atlas Sheds, we offer a wide range of high-quality garden sheds, wooden sheds, workshops and storage buildings to suit gardens of all shapes and sizes. 

Whether you need a compact shed for everyday garden tools or a larger building for bikes, equipment or workshop space, our team can help you choose the right option. 

Browse our range of garden sheds today or get in touch with Atlas Sheds for advice on choosing the best shed for your garden. 

FAQs

What is the best shed base? 

For most small to medium sheds, paving slabs are usually the best choice in terms of strength, cost and durability. Whereas larger sheds and garden buildings will need a concrete base. 

What is the best shed base for grass? 

You shouldn’t install a shed directly on grass, even if it appears flat and firm. The soil underneath retains water; it will soften in the wet weather and settle unevenly. 

Does a shed need a concrete base? 

No, not every shed needs a concrete base. Concrete is the best choice for large sheds and workshops. But smaller sheds can suffice with paving slabs, plastic grids or raised timber frames. Just remember a shed base needs to support the total weight of the shed and its contents, not just the empty building. 

Are paving slabs good for a shed base?

Yes, paving slabs are a reliable choice for many small and medium-sized sheds. They give a firm, level surface. But you need to prepare the ground properly before you lay the paving slabs. Each slab needs to be level to prevent the shed frame from twisting.  

Can I put a shed on gravel? 

A shed can be installed over gravel, but it shouldn’t be placed directly onto a loose pile of stones. Gravel can move under pressure, especially when it’s not compacted properly. For a more stable base, use compacted gravel within a timber or concrete perimeter or install a plastic grid system that keeps the gravel evenly distributed. 

What is the best shed base for uneven ground? 

Ground screws are one of the best options for uneven or sloping ground. Each support can be set to a different height, allowing you to create a level frame without needing to excavate the whole area. Don’t use loose blocks, offcuts of timber or stacked slabs to make a flat surface as these can shift over time and it’ll end in disaster for your shed’s stability. 

Do I need a damp-proof membrane under a shed base?

They’re mostly used under a concrete shed base to prevent moisture from rising through the slab. A membrane is not usually needed beneath a free-draining gravel or plastic grid base.