A rain gutter is part of a building’s water discharge system. It is a trough or channel that runs around the perimeter of a roof, and collects rainwater runoff from the roof, discharging it, usually to rainwater downpipes which convey it to a drainage system. Gutters are available in a variety of forms, styles, sizes, and materials. Half-round gutters, as their name suggests, are essentially tubes that have been split in half lengthwise. They don’t have flat sides, which makes installation a bit trickier than with regular gutters.