Our 65mm square cast iron downpipe is available in 2.5m lengths. Cast Effect square downpipe is often used in conjunction with ogee gutter systems, although circular pipe can equally be used with ogee.2.5m lengths are usually sufficient for rainwater pipe drops on single storey buildings but for two and three storey buildings the pipes can be joined together with pipe sockets. This is to imitate the way in which original cast iron pipe drops were created.Rainwater pipes are always a pushfit joint - never use silicon or solvent weld on these systems as there might be a requirement to take them apart for cleaning or unblocking at some point in the future.