This is one of the most frequently asked questions when it comes to buying a garden shed!
First things first: We always recommend choosing a shed that comes with a built-in base on pressure-treated floor bearers. These bearers lift the shed off the ground and allow airflow underneath, crucial for keeping the base dry and extending the life of your shed. While pressure-treated timber offers protection against rot and insects, it’s not immune to long-term damp conditions. That’s why the surface it sits on is so important.
If your shed will be placed in a damp area. Under trees, on heavy clay soil, or somewhere prone to water logging. It may be worth upgrading to recycled plastic bearers. These won’t rot and can help prolong your shed’s life even in tough conditions.
Important: Grass, soil, or bare earth are not suitable surfaces for your shed. These can hold moisture, cause subsidence, and lead to premature rot, even if they’re out of sight after installation. A properly prepared, level, and solid base is essential.
So, what are your options? Here are some of the most popular shed base materials:
1. Type 1 Hardcore or Stones
Type 1 (a crushed stone aggregate) is a cost-effective and easy option, especially for smaller sheds or in gardens with good drainage. The stones are usually laid within a timber frame to hold them in place, unless your base is surrounded by walls or paving.
Materials: 100–150mm of Type 1 hardcore, 100x50mm pressure-treated timber for the frame
Tools needed: Spirit level, ground pegs, and ideally a wacker plate (available for hire)
DIY skill level: Moderate
Our verdict: An affordable and simple option for competent DIYers. Provides excellent drainage, but care is needed to make sure it’s level and compacted.
2. Concrete Base
Concrete is the most durable and permanent option, perfect for large or heavy sheds. It should be a minimum of 100mm (4 inches) thick, laid on a compacted gravel sub-base to allow drainage and prevent cracking.
Steps: Excavate the area, lay a sub-base, build a wooden frame, pour and level the concrete
Curing time: At least 48 hours before use
DIY skill level: High
Our verdict: Ideal for long-term durability and stability, especially for larger buildings. However, it requires skill and proper safety precautions—this is one best left to the professionals unless you’re experienced with concrete.
3. Patio Slabs
Slabs offer a solid, attractive base that can blend nicely with surrounding paths or patios. They must be laid level and on a sand and cement mix to stop movement.
Installation: Lay on compacted sand and cement, check levels, and point gaps after 48 hours
Surface: Should be at least the same size as your shed (or ideally larger)
DIY skill level: Moderate to high
Our verdict: A durable, long-lasting option if laid properly. If your base extends beyond the shed footprint, consider installing guttering to stop splash back that can lead to rot.
4. Timber Decking
Timber decking can double as a functional shed base and attractive garden feature. With the rise of pressure-treated boards, decking is now more resistant to rot and easier to maintain.
Best for: Smaller sheds or garden storage
Note: Not ideal for heavy or insulated sheds due to weight limitations
DIY skill level: Moderate
Our verdict: A stylish and practical solution for small sheds, especially if you already have decking in place. Less suitable for larger buildings.
5. Recycled Plastic Base Kits
These modular systems have surged in popularity. They’re lightweight, easy to install, and very effective for drainage. Kits often include everything you need: membrane, plastic grids, and support feet.
Popular brands: Probase and others, available online
Best for: Standard shed sizes (e.g. 6x4, 8x6, 10x8)
DIY skill level: Easy
Our verdict: An excellent low-effort option for well-drained, level ground. Especially handy for those who want a durable base without mixing concrete or laying slabs.
Final Thoughts
No matter which option you choose, the key to a long-lasting shed is a level, dry, and solid base. Take the time to plan your base properly, it’s not the most glamorous part of the build, but it’s absolutely the most important.
Need help choosing the right base for your shed and garden? Drop us a message with your shed size and site conditions, we’re always happy to help you decide.