Cavalier chairman George Adams said Alston had been a highly respected chief executive.
"The company now has zero debt, a strong and experienced leadership team and the financial resources to execute our new strategy which positions Bremworth as a global leader in designing and creating desirable, high performing, safe and sustainable interior products."
Alston said it had been a privilege to lead the company.
"I am particularly proud of what the Cavalier team has accomplished during challenging times, and the development of a new strategy that will see Cavalier lead the way in sustainability in the carpet sector," he said.
It was the right to time to hand over the reins, as the firm was well-positioned to implement its five-year strategy, he said.
He will stay on while the board commences a formal process to appoint a new chief executive.