 Permanite, Britain's biggest roofing felt manufacturer, and Limmer, a quoted asphalt company, were bought in 1971, while the 1973 purchase of Mitchell Construction (which had foundered on the Kariba Dam) strengthened the construction division.However, the acquisition which was to radically change the direction of Tarmac was McLean Homes bought at the beginning of 1974.McLean was run by Eric Pountain, a one time estate agent who had sold his own housebuilding business to McLean, later taking over as managing director in a boardroom coup.