Frontman Richie Lewis said he was heartened by the fact the gig announcement had been so well-received the show had to be moved to a larger venue to accommodate more people.

"We're very proud to be involved in it," he said.

"When we were asked to be involved with (headlining act and home-town heroes) Hockey Dad, I knew it was going to be too big initially for Windang. Tickets flew out the window."

The fundraiser was initially scheduled to take place at Club Windang.

Instead, the sold out show will now be on at North Wollongong Hotel on Friday.

"It's about raising money for the firies, wildlife and those affected," Lewis said.

"So we'd be doing a disservice if we weren't able to get all those people in and get as much money as possible for them."

Lewis said the music community had rallied to support the bushfire relief cause.

"I've seen a few posts on social media about how earlier in the year arts funding was taken... Was completely wiped by the federal government, and it seemed like there was not really much value given to the arts community," he said.

"When you see an event like this and how much money artists have contributed, concerts taking place all over the world, and artists digging deep from all over the world to contribute to recovery, it's really amazing."

The concert, called 'Fire Fund', will also feature Dune Rats (DJ Set), Shining Bird, Totty and Maddy Jane.

One hundred per cent of all tickets, raffle, merchandise proceeds and donations on the night will go to the NSW Rural Fire Service, NSW National Parks and Wildlife Services, and the Red Cross Disaster Relief Fund.

Acknowledging they were "the oldest people on the bill", Lewis said it "would be interesting for Tumbleweed", given they would be playing to many younger Hockey Dad fans.

"We're just staying focused on the reason why we're doing it," he said.

"It's all we know how to do, how we can contribute, and that's why we're doing it."

Hockey Dad have set a goal of raising $150,000 from the show.

Lewis was confident they could reach the fundraising target.

"I think in ticket sales alone it's already over $100,000," he said.

"And there's quite a bit of merch for sale on the day, and auctions with some pretty awesome things up for grabs.

"I can see the generosity of people is pretty amazing, and hopefully we'll get there."

Read more: Windang band Hockey Dad to headline 'Fire Fund' bushfire relief fundraiser later this month