Richard Burr shares his top tips for a DIY rainwater butt.

The reason everyone should have a water butt

They’re easy to fit and if you have the space, you can pop one on each rainwater pipe of your house. Here are my tips for fitting a rainwater butt...

There are lots of pipes outside my house - which ones do I use?

It is generally considered good practice to fit most buildings in the UK with roofs.

Rain falls on roofs and collects in guttering, which then flows into downpipes and either soaks away in the surrounding ground or is piped away as waste.

Your downpipes are easy to recognise, as, if you look up at your roof, they are connected to your guttering. Do not get them mixed up with your soil pipes (which carry waste from your sinks, baths and toilets and into the sewer) - your water butt will still fill up, but you won’t want to spread the result on your garden.

Rain water pipes are usually 65-68mm in diameter for houses in the UK, soil downpipes are 100mm. This guide will show you how to connect to PVC pipes, which are the most common type. If you’re choosing which downpipe to connect to, use one that gets its rain from a large portion of the roof - you won’t fill a water butt up that quickly from a porch roof, for example. But if you want to, you can also fix a butt to sheds, greenhouses and garages - as long as they have guttering.

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To do this job you will need:

A water butt (with stand, to raise it off the ground)

A water butt diverter kit, to match your downpipe

A tape measure

A spirit level

A hack saw

A drill with a 25mm bit

A rubber mallet (or block of wood and a hammer)

A concrete paving slab and sharp sand (if fitting on an uneven surface)

Be sure to raise your butt off the ground

Depending on how much space you have, you can buy water butts that hold various volumes of water, from 25 litres up to over 500 litres. Slim ones are easy to come by and will fit discreetly down a side passage. Most butts will be in the 100-120 litre range and are perfectly adequate. But no matter what sort you get, they need to be mounted on a solid surface and be high enough from the ground to be able to get a watering can or a bucket underneath.

Most water butts have a compatible stand or staging that they come with, otherwise you can easily pick one up. Remember, a litre of water weighs 1kg, so depending on what capacity you buy, your stand will need to potentially carry quite a lot of weight. If you are situating your water butt on an already solid surface, you can place the staging directly onto this. If you are putting the water butt on something less than solid (a flower bed, for example) you’ll need to lay a paving slab nice and level.

To lay a level paving slab, clear away the loose soil where you want your slab to go, loosely spread 50-75mm of sharp sand and gently lay the slab on the sand. Put a spirit level on the slab and tap it down with a rubber mallet (or lump of wood if you don’t have one) until it’s firmly set in place. The connector pipes for water butt diverters are usually 50cm long, so try not to set your butt further away from the downpipe than this.

Fitting the diverter

Once your staging or stand is set, you can plonk (technical term) the water butt on top of it and fit the piping. Your butt will come with a tap fitting, which goes at the bottom and will be fairly easy to screw into place - make sure you tighten it up well, or you’ll have a slow drip that will empty the butt annoyingly quickly.

Now you can fit the diverter. This is the piece of equipment that takes water from the downpipe and channels it into the butt. It’s very important that the diverter is attached to the downpipe below the top level of your water butt, or once the butt is full with rain, the butt will overflow, rather than allowing the water to just continue down the downpipe.

Using your spirit level, mark the top of the rim of your water butt against the downpipe. Measure 3cm down from here and cut through your downpipe with a hack saw (try to make the cut as level as possible). Pull the two ends of downpipe apart and insert the diverter, then push them back into place.

Measure 5cm down from your cut in the downpipe and use the spirit level to mark this on the water butt - this is the height you’ll need to drill the hole in the butt to connect the other end of the diverter. It should say on the diverter packet what diameter drill bit to use, but they are usually around 25mm.

Connect the pipe to the butt, clear up, run back indoors and wait patiently for it to rain.