Recommended for a roof area of up to 50 m².
Six of the seven listings in this family do not mention roof area at all, and it
is the number that actually sizes a water butt.
Because a butt’s capacity is not what limits it
People choose a butt by litres. What decides whether it is the right butt is the
roof feeding it.
A small roof in a dry month delivers very little, and a 450-litre tank stands
half empty. A large roof in one storm delivers more than 220 litres in minutes,
and everything past that goes straight back down the pipe — so the extra
capacity is never used either.
Fifty square metres is a garage roof, a large shed, one side of a small house
extension. Matching the collector to it is the difference between a butt that
fills steadily and one that is either dry or overflowing.
One manufacturer out of seven publishes it.
The collector, included, with the part that matters
Named in the listing: a downpipe connector that filters dirt out of the inflow,
fills the butt automatically, and stops the flow once the water level is
high.
That last clause is the important one.
A butt fed by a simple diverter keeps filling and then overflows — at the top,
against the house wall, which is the single worst place for running water. Damp
walls, undermined paving and a permanently wet corner are what that produces
over a winter.
A collector that stops diverting once the butt is up sends the surplus back down
the downpipe, where the drain is already designed to take it.
Five of the seven butts here do not include a collector at all, and one states
explicitly that it is not in the box.
16 millimetres
The clearance needed between the downpipe and the house wall for the connector
to fit.
That is a strangely specific number and it is exactly the kind that saves a
return. Downpipes on older houses sit hard against the wall on short brackets,
and a collector that needs 40 mm of room will not go on.
The connector also fits downpipes from 70 to 100 mm in diameter, which
covers almost everything domestic.
Two 19 mm threads
Both published, and the second use listed for them is the one to note: a tap, a
hose set, or draining the butt before winter.
That is the whole maintenance regime for every product on this shelf. Water
expands as it freezes, and a butt left full through a hard frost bulges, splits
at a seam, or breaks its tap off.
An outlet at the bottom means draining takes a minute rather than a bucket and a
siphon.
The planter, and the catch nobody mentions
A removable tray, 20 cm deep, on the top.
Twenty centimetres is a real planting depth — enough for bedding, herbs,
strawberries or a trailing display, and not enough for anything woody.
The catch is structural rather than cosmetic: the top of a water butt is a lid
whose job is to shed rain into the tank. A planter sitting on it is in a
rain shadow of its own making. It will not water itself, and in July it will
need doing every day.
From the butt directly underneath it, which is at least convenient.
About 0.56 € per litre
The dearest capacity on this shelf, where the range runs from about 0.25 €.
What that buys, specifically: the downpipe connector, the filter, the automatic
cut-off, the 19 mm outlets, recycled material with a stated high UV protection,
and the only published roof-area figure in the family.
The cheap end of this shelf buys plastic and a tap you drill a hole for.
What goes unpublished
No dimensions.
That is an odd omission on a butt whose first feature line sells it as slim and
efficient against a house wall, because the footprint is the thing being
claimed.
Across the five butts on this shelf that do publish dimensions, litres per square
metre of ground run from 707 to 1,250 — and the shape, not the capacity, decides
where in that range a butt falls. This one cannot be placed on that scale.
Availability
From 122 € to 177 €, that being the spread across the German, Italian and Spanish Amazon stores on the day of the survey.
More than 1.6× the cheapest country at the French Amazon store; a gap of that size normally means forwarded stock rather than a seller on the ground, so the spread above leaves it out.
Listed and unsold: the American and British Amazon catalogues hold the reference with nobody behind it.
Taken from Keepa on the day this page was last revised; stock and prices move without notice.
Prices quoted in this text were read on 26 September 2026. The live price is at the top of the page.
