Rain Chain

A rain chain is a length of chain, or a string of open-bottomed cups, hung from a gutter outlet in place of a closed downspout. Rainwater clings to and runs down the chain or drops from cup to cup, turning runoff into a visible and audible water feature. The water is typically received by a basin, gravel bed, drain or storage container at the base.

Origin

Rain chains are long established in Japan, where they are called kusari-doi (also romanised kusari-toi), meaning chain gutter. They are a familiar feature on Japanese temples and houses. Scandinavian vernacular architecture used a comparable idea, a simple stick or pole guiding water from the roof. Modernist architects in the 20th century also used chains to contrast with concrete or stone facades.

Types

• Link chains: a series of open links, sometimes of shaped or decorative form; water clings to the chain as it runs down.
• Cup chains: a series of small cups, each with a hole in its base, chained together so water fills and overflows from one to the next. Cup chains usually handle more water with less splashing than plain links.

Copper, brass, aluminium and steel are common materials; copper weathers to a brown and eventually green patina.

Practical considerations

• Rain chains handle less flow and splash more than a closed downspout, so they suit smaller roofs, sheltered locations or as one of several outlets.
• The bottom of the chain is usually anchored to prevent swinging in the wind.
• In cold climates, ice can build up on the chain, adding weight to the gutter; fixing points should be strong enough.
• Ground at the base should drain away from the foundation.