Collecting rainwater is one of the easiest and most cost-effective steps towards a self-sufficient garden. In this guide, you’ll learn how to set up a water butt in a UK garden — from choosing the right water butt size to connecting it to a downpipe for simple rainwater collection.
Whether you want to install a water butt to reduce water bills, help your plants thrive, or prepare for hosepipe bans, this step-by-step water butt installation UK guide covers everything you need.
Why Install a Water Butt?
- Save money: Reduce your water bills by collecting and reusing rainwater.
- Better for plants: Rainwater is soft, chemical-free, and perfect for garden use.
- Stay resilient: During hosepipe bans or summer droughts, your water butt system will keep a steady supply ready.
- Eco-friendly: Less reliance on mains water means a smaller environmental footprint.
Choosing the Right Water Butt Size (UK Options)
When learning how to set up a water butt, choosing the right size is key:
- Small water butts (100–200 litres): Great for patios or balcony gardens.
- Medium water butts (200–500 litres): Ideal for average gardens and allotments.
- Large water butts (500–1,000 litres): Best for large gardens, polytunnels, or high self-sufficiency setups.
💡 Tip: Instead of one huge tank, try connecting multiple water butts — one by your shed, another near your greenhouse — for maximum rain capture.
👉 Compare popular water butt sizes UK and prices on Amazon UK or at your local garden centre.
Step-by-Step Water Butt Installation (UK Guide)
1. Pick the Perfect Location
Place your water butt next to a downpipe on your house, shed, or greenhouse.
Ensure the surface is level and solid — paving slabs are ideal.
Raise the water butt on a stand or bricks so you can easily fill watering cans.
2. Install the Diverter Kit
Most UK water butt kits come with a diverter that connects to your downpipe.
- For plastic downpipes, mark the correct height and cut carefully with a hacksaw.
- For cast iron downpipes, use an angle grinder or seek professional help.
3. Connect the Hose
Attach the supplied hose to channel rainwater from the downpipe into your butt.
Once full, the diverter automatically redirects excess water back to the drain — making connecting a water butt to a downpipe simple and automatic.
4. Secure the Lid
Always keep the lid on tight to prevent algae, debris, and insects from entering.
Expanding Your Rainwater Storage
- Multiple downpipes: Install a water butt under each downpipe to capture more rainwater.
- Linking butts: Use a connector kit to connect two or more water butts, letting the overflow from one fill the next.
Seasonal Water Butt Maintenance
- Winter: Leave space at the top for ice expansion or drain during deep freezes.
- Spring: Clean the inside to remove any algae or sludge before reconnecting.
Maintaining your UK water butt installation ensures clean, usable water all year round.
Beyond the Basics – Other Rainwater Systems
Once you’ve mastered how to set up a water butt, you can expand into larger storage tanks or underground systems — perfect for big gardens or off-grid living.
Final Thoughts
Setting up a water butt in the UK is one of the most rewarding upgrades for any gardener. With simple installation steps and sizes to fit every garden, you can collect hundreds of litres of free rainwater — ready for your vegetables, flowers, and greenhouse crops.
If you’d like ideas of where to use your newly collected water, why not check out our guide on how to grow vegetables indoors in buckets.
Looking for more self-sufficiency and gardening guides? Visit HomeGrower to explore all our latest indoor and outdoor growing tips.
For more information on all topics growing and gardening related, we recommend heading over to the Royal Horticultural Society’s Website.
What is the best place to put a water butt?
Place it on a firm, level surface next to a downpipe. Raising it on a stand or bricks makes it easier to fill watering cans.
Can you connect a water butt to any downpipe?
Yes. Most diverter kits fit round or square plastic downpipes. For cast iron, you may need an angle grinder or professional help.
How many water butts can you connect together?
You can link two or more butts with connector kits, so when one fills, the overflow runs into the next.
What size water butt do I need?
Small butts (100–200L) suit patios, medium (200–500L) work for average gardens, and large (500–1,000L+) are ideal for polytunnels or high water use.