The outer wall is corrugated providing excellent structural strength which reduces the possibility of on-site damage. The inner wall has a smooth seamless finish to assist hydraulic flow. The design unlike traditional single-wall pipe prevents silt accumulation. This twinwall plastic drainage pipe is supplied either fully perforated or half perforated depending on application required. The small perforations in the pipe enable water to be collected and carried away to a soakaway, water course or surface/rainwater drainage system. This pipe is ideal for land drainage and flood risk or stormwater management applications. Complies to BBA, HAPAS Roads & Bridges and Network Rail certificate of Acceptance.