Uncovering asbestos on any build is terrifying, but for twins Luke and Josh, discovering it while renovating their home on The Block was downright devastating, as their dad Kevin is fighting for his life thanks to the deadly substance.
"I know the dangers of it firsthand and I wanted to stay well clear of it," Josh tells Woman's Day.
"If you breathe in those particles, they're in your body for life."
"It was a bit of a shock when we found it and it reminded us of the ordeal our dad is going through," adds Luke of Kevin, 61, who was diagnosed with mesothelioma, a cancer that affects the tissues that line the chest and abdomen, the space around the heart and other organs.
The former real estate agent developed the illness after coming in contact with asbestos while inspecting houses during his career.
"I ingested it at some stage and it sits in the lining of your stomach for 20 to 40 years before anyone knows," Kevin tells Woman's Day.
"It's a very nasty form of cancer, sadly."
Luke says learning of his father's disease was "heartbreaking".
"For years they thought he had an autoimmune disease and then one day they decided to cut him open and have a look and found mesothelioma sprawled throughout his organs. It hit us really hard, and especially when you find out how deadly [it] is," he says.
"It's an incurable cancer – it's always going to come back. He's just trying to hold it back from growing fast."
After surgery last year to remove parts of his stomach and colon, and several sessions of chemotherapy, Kevin says he's had two scans "showing a clean bill of health for the time being, but I just take every day as it comes".
Ever the optimist, he says his illness has brought the family "even closer".
"When you get this sort of news, it makes you reflect and look at your values, and you just don't take anything for granted," says Kevin.
"It makes you look at every day as a special day."
Josh and Luke, 27, say they're proud of their dad's resilience.
"He's done exceptionally well. He's gone through a very difficult six months, but he's come out on top," Josh tells Woman's Day.
And seeing his boys on The Block has given the retiree a much-needed boost.
"He was so excited for us," says Luke.
"I used to work with my dad in real estate so I always shared an interest with him in property. It was a massive shock to him that we got on it."
And Kevin's just as surprised at what the twins have managed to achieve with their renovation.
"From two guys who didn't have any hands-on experience, they just threw their hat in the ring and did an amazing job. I'm very, very proud of both of them," he tells Woman's Day.
Luke admits he and Josh were "absolutely" underestimated by the rest of the Blockheads thanks to their 2019 stint on Love Island, but they feel they've more than proved themselves.
"We would be the most inexperienced team ever on The Block," he says.
"This year they all have a lot of renovation experience but we've never done any renovation whatsoever and we really wanted that challenge to show if you really put your mind to it, anyone can renovate a home," says the reality star, who thinks Mitch and Mark are their biggest competition.
"But it's anyone's game, at the end of the day."