Copper Guttering Square 80mm Outlet to Round Downpipe. Description Our Square copper downpipes are manufactured from 100% natural 0.6mm copper and are supplied in 2.4m lengths, making both transportation and installation uncomplicated. Each length is swaged at one end so they push fit together, with additional joints available so you can use up all your off cuts. 1mm thick heavy duty pipes are available for high risk areas such as alley ways and school playgrounds. Standard profile measures: 80 x 80mm