The public will still be able to shop at Gays Mitre 10 in Howitt Street, but the 1977 building - which has seen several extensions - will be renovated between now and March.

Trade Sales Manager Jake Weber said it was business as usual during the changes.

"The work's already started. We have new racks and have also laid slabs. Some of the walls are coming down as well," he said.

"The Wendouree store is our biggest - at 9000 square metres - and 95 per cent of our customers are already tradies."

Ballarat's two other Gays Mitre 10 stores will remain open - and continue to focus on everyday retail trade.

Mr Weber said staff numbers would remain - and possibility increase - after the renovations were finished.

He said members of the Gay family were still actively involved in the business, over a century after it began selling building supplies and mining equipment.

Godfrey (Gough) Gay set up the first hardware shop with Bill Valpied and George Norris in 1918.

G Gay and Co Pty Ltd expanded over time, with second, third and now fourth generations joining the team.

The Wendouree store was the largest hardware store in Ballarat when it opened in 1977

The Gillies Street South site was purchased in 1991 and another in Albert Street Sebastopol in 2014.

The three stores switched from Home Hardware to Mitre 10 branding almost a decade ago.

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