Shed Foundations: 9 Solid Bases and How to Choose the Right One

If you've ever tried to find the "perfect" shed base, you'll know one thing right away: there isn't a one-size-fits-all solution. Some sheds sit on spongy grass. Others on rocky slopes. And then there are those monster sheds that weigh as much as a small car.

So before you reach for a bag of cement or click "buy" on a plastic grid base, it pays to step back and ask: What's my shed really going to sit on?

I've built sheds on more types of ground than I care to remember - from flat concrete pads to sloped gardens held back with retaining walls. And each situation needed something a little different.

That's why I put this guide together: to walk you through the 9 most reliable shed foundation types, explain when to use each one (and when not to), and link you to full how-to guides for every base.

Let's start with the most solid option of all...

Poured Concrete Shed Base: The Big One

1. Concrete shed base

Want your shed to feel like a house? A poured concrete base - often called a "raft" - is the go-to option.

Completed concrete shed base before commencing shed construction

This is the heavy-duty choice. It's what I'd use for a workshop, a big garden office, or any shed that needs serious staying power. You can reinforce it with steel or keep it plain - either way, it gives you a rock-solid, level foundation that won't shift or sag over time.

Good for:

Large, heavy sheds

Permanent installations

Areas with soft ground

Watch out for:

Heavy work and curing time

Higher material and labour cost

It's not easily removable - this is a commitment

Read more:

How to build a concrete shed base

Using timber shed bearers to support your shed

Budget-Friendly Bases That Work

Not every shed needs to sit on a concrete slab. If you're building a lightweight garden shed or just want to keep costs down, these options can do the job nicely.

2.Plastic Grid Base

These are the lightweight honeycomb-style panels you can fill with gravel. Ideal for small sheds, they install quickly and provide decent drainage.

Interlocking plastic foundation grids

Good for:

Small garden sheds

Fast, dry installation

Watch out for:

Needs a well-prepared surface

Limited load-bearing capacity

3.Paving Slabs

A tried-and-tested option. Place them on a bed of sand and hardcore, level them off, and you're good to go. Still one of the best DIY solutions.

Shed foundation using concrete paving slabs

Good for:

Medium sheds

People on a budget

Watch out for:

Precision levelling is key

Not ideal on soft or shifting soil

4.Timber Frame on Gravel

Make a wooden base (often with treated timber), lay it on gravel to allow for drainage, and secure your shed on top. It's quick and allows airflow underneath.

storage shed foundation Building a shed foundation with timber bearers

Good for:

Temporary or moveable sheds

Sites where you want to avoid concrete

Watch out for:

Timber must be treated

Keep an eye on long-term stability

Foundations for Sloping Sites: Holding Back the Hill

Got a garden with a slope? Don't worry. You don't have to dig out half the hill to get a level shed. Here are two clever ways to work with the land.

shed on sloping site Which option is best for you?

5. Retaining Wall Base

Build a short retaining wall with concrete blocks or sleepers, backfill it with compacted material, and place your shed on top. Think of it like a terrace in your garden - one that just happens to support your new shed.

Good for:

Steeper slopes

Creating a usable, flat area

Permanent garden features

Watch out for:

Needs good drainage behind the wall

More digging and block work required

6.Pier and Beam Foundations

This is the shed version of a stilt house. Concrete piers are set into the ground at key points, and a timber frame sits on top.

Shed pier foundation

Good for:

Sloped sites where you don't want to move lots of soil

Minimal disturbance to roots or existing planting

Watch out for:

Precision digging and levelling needed

Requires accurate layout and beam work

Adjustable Bases: Quick to Level, Easy to Move

I've built sheds in all sorts of places - half on patios, half on old footings, and sometimes just across a section of hardstanding where nothing is quite level. In situations like these adjustable base systems are invaluable

7.Adjustable plastic base: Simple, Reliable Support on Hard Ground

For most sheds built on patios, driveways, or other hard surfaces, I usually recommend a plastic base kit - specifically, the DryBoot shed bearer support. It lifts the floor just enough (20mm) to protect your timber from rising damp, improves ventilation underneath, and makes it easier to level the shed floor using spacers and shims.

shed door hinges Dryboot supporting bearers with shed floor placed directly on top of bearers

Good for:

Sheds on solid, gently sloping hardstanding

Quick installs without the need for fixings

Keeping timber bearers dry and ventilated

Watch out for:

Not suitable for very soft ground or steep slopes

Bearers need to be well-aligned to distribute the load evenly

8.Steel Adjustable Base: Level and Lift on Challenging Terrain

When the ground is really uneven or the shed is larger and heavier, I turn to a steel adjustable base system like the Quick Jack. It uses galvanised jacks to support a timber frame - you simply turn each one to raise or lower the height until the whole base is level.

Adjustable shed foundation - metal jacks

Good for:

Mixed or uneven ground (e.g. part soil, part slab)

Large or heavy sheds and summerhouses

Creating excellent airflow and damp protection

Watch out for:

Requires a bit more setup time and planning

Costs more than simpler plastic base systems

Ground Screw Base: The Pro Option for Tricky Sites

9.Ground screws

These are like giant steel screws that twist into the ground, forming instant foundation points. They're used for everything from decking to modular homes, and they work great for sheds too.

Close up of ground screw with timber bearers

Good for:

Uneven or soft ground

Faster installs with minimal digging

Watch out for:

You'll need specialist tools (or a contractor)

Higher upfront cost, but excellent long-term value

Hidden obstructions such as rock and services such as gas pipes and electricity cables

Foundation FAQs: Clearing Up Common Questions

Q: How deep should my shed foundation be?

It depends on the type, but most lightweight sheds don't need deep footings. You just want to make sure the base is level and stable.

Q: Will my shed move or sink over time?

Only if the ground shifts beneath it. That's why proper preparation - especially good drainage and compacted material - is key.

Q: Do I need to anchor my shed to the base?

Yes, especially in windy areas. Most sheds have fixings that let you screw or bolt them to the base.

Final Thoughts: Build the Base that Works for Your Garden

There's no single "best" shed foundation. It all comes down to your soil, your slope, your shed - and how long you want it to last.

What matters most is choosing a foundation that matches your needs, and that you install it properly. Cut corners here, and you'll feel it every time it rains, the wind blows, or you open the door and find the floor's not quite level.

So take a few minutes to explore your options above, and check out the linked how-to guides. If you build the right foundation, you'll only have to do it once.