Becko
Considering installing a shed? Wondering how to build a shed base with paving slabs in the garden? Whether you need more storage space, a workshop, or even a tiny backyard bar (yes please!), the first step is making sure you’ve got a solid, level base. And paving slabs are a great option: cost-effective, sturdy, and relatively straightforward if you’re up for a bit of DIY.
On the blog today I’m going to walk you through exactly how to build a shed base with paving slabs. No confusing jargon. No fancy tools you don’t already have. Just a simple, step-by-step guide.
Why Use Paving Slabs for a Shed Base?
The magic question! Paving slabs are ideal for smaller to medium-sized sheds and offer a solid, level surface that will keep your shed dry, stable, and upright for years to come. They’re also widely available, fairly inexpensive, and easy to lay yourself with a bit of patience and elbow grease.
And let’s be honest: there’s something quite satisfying about doing it yourself and being able to say, “I built that.”
How to Build a Shed Base with Paving Slabs: Tools and Materials You’ll Need
Before you get started, make sure you’ve got everything you need:
Tools:
- Shovel
- Rake
- Spirit level
- Rubber mallet
- Tape measure
- String line and pegs
- Wheelbarrow (optional but useful)
- Garden hose or watering can
- Gloves (your hands will thank you)
Materials:
- Paving slabs (obviously!)
- Sharp sand or a mix of sharp sand and cement
- Hardcore or MOT Type 1 (for the sub-base)
- Weed control membrane
Step-by-Step Guide: How to build a shed base with paving slabs
1. Measure Up
First things first: measure your shed. Then add about 5-10cm extra on each side to allow a little wiggle room. Mark out the area using pegs and string so you can visualise the space. Double-check your measurements before digging!
2. Dig Out the Area
Time to get digging. You want to dig down to about 15-20cm deep across the whole area. This gives you space for your sub-base (hardcore) and your laying course (sand/cement). Remove any grass, roots, and large stones.
3. Add the Weed Membrane
Lay a weed control membrane across the base of your dug-out area. This helps stop weeds from creeping up between your slabs later on. It’s not essential, but highly recommended.
4. Lay the Sub-base (Hardcore)
Add around 10cm of hardcore or MOT Type 1. Rake it out evenly and compact it as much as you can. If you’ve got access to a wacker plate, even better! But stomping around on it a bit will do in a pinch. The sub-base gives your shed base its strength and stops it from sinking or shifting.
5. Lay the Sand (or Sand/Cement) Layer
Next, add a layer of sharp sand or a mix of sharp sand and a little cement (say, 8 parts sand to 1 part cement). This is your laying bed. It should be about 4-5cm deep. Use a rake to level it out and a straight edge (a piece of timber works well) to screed it flat. Check it’s level with your spirit level.
6. Lay Your Paving Slabs
Now for the fun bit! Start laying your paving slabs in one corner and work your way out. Use a rubber mallet to gently tap each slab into place. Check each one is level and adjust the sand underneath as needed.
Leave a small gap (a few millimetres) between each slab to allow for movement and drainage. Use spacers if you want to be really precise.
7. Check Everything is Level
As you go, use your spirit level across and along the slabs to make sure everything is even. If something’s not right, lift the slab, add or remove a bit of sand, and try again. It’s fiddly, but totally worth it.
8. Brush Sand into the Gaps
Once all the slabs are laid and you’re happy with how they look, brush some dry sharp sand (or kiln-dried sand) into the gaps to help lock everything in place. Give it a light water with your hose or watering can to help it settle.
9. Pat Yourself on the Back
Seriously. You’ve just built a shed base! That’s no small feat. Now you’re ready to start assembling your shed.
Bonus Tips for Shed Base Success
- Double Check the Ground: If your garden is particularly uneven or on a slope, you may need to do a bit more digging and levelling. Don’t skimp here or your shed will suffer later.
- Use Treated Timber for Edging: If you want a nice clean edge, consider adding a timber frame around your base to contain the slabs and sand. It also gives it a neat finish.
- Don’t Rush It: Take your time levelling each slab. Rushing here can mean a wobbly shed down the line.
- Leave It for a Day: If possible, let the base settle for 24 hours before building your shed on top.
FAQs: How to build a shed base with paving slabs
Do I need planning permission to build a shed on a slab base?
In most cases, no. As long as your shed is under 2.5m tall and not taking up more than 50% of your garden, you’re usually good to go. But always check with your local council if you’re unsure.
Can I build a shed base straight onto soil?
Technically, yes. But we wouldn’t recommend it. Soil moves over time, which can lead to an uneven base and a wonky shed. Adding a proper sub-base is the key to a long-lasting shed.
What’s better: concrete base or paving slabs?
Depends on your needs. Concrete is more permanent and stronger for large sheds, but it’s also more work. Paving slabs are easier for DIYers and perfect for smaller sheds.
How many paving slabs do I need?
Calculate the area of your shed base (length x width) and divide that by the size of your slabs. For example, if your base is 2m x 2m (4m2) and your slabs are 600mm x 600mm (0.36m2), you’ll need around 12 slabs.
Can I lay slabs in the rain?
Ideally, no. Wet weather can make it harder to level the sand and may affect your cement mix. If the forecast looks grim, wait for a dry spell.
Building a shed base with paving slabs might seem a bit daunting, but take it one step at a time and you’ll be surprised what you can achieve. With the right prep, some basic tools, and a bit of perseverance, you’ll have a solid base that’ll keep your shed standing proud for years.
So grab your gloves, cue up your favourite playlist, and get stuck in. Your future self (and your garden) will thank you!