The extension of Takoradi Docks was undertaken to accommodate the burgeoning ivory trade. On his return to the UK, Percy began to develop a reputation for the high quality of his work on roofs, which he and his team laid with Westmoreland slate and pinion pantile.
During the Second World War, Percy worked on the many aerodromes and various army camps around the country, before moving on to repairing the vast amount of bomb damaged homes affected by the Blitz.