James Hardie has been forced to borrow more money and seek financing from a larger number of banks to complete the $14 billion buyout of American outdoor deck company Azek, a transaction that is already opposed by many of the building materials giant’s shareholders.

Documents filed with the Securities and Exchange Commission show the merger is expected to cost $US300.6 million ($467 million) to complete, almost entirely interest expenses related to a bridging loan. This is higher than the $US270.4 million investors were told earlier this year.