"The Hunger Games" star, who was tasked with rescuing the pair's pets from the blaze, tells GQ Australia the disaster brought himself and Miley closer than ever - and they decided to exchange vows at their home in Franklin, Tennessee just over a month later.
"We wanted to make a new part of our lives," he tells the magazine. "Going through something this emotional with someone brings you closer."
Miley also recently told Vanity Fair the disaster hastened their wedding, explaining, "I'm not sure without losing Malibu, we would've been ready to take this step or ever even gotten married, who can say? But the timing felt right and I go with my heart. No one is promised the next day, or the next, so I try to be in the now as much as possible."
"I would say that losing the house changed us much more than getting married changed us. When you experience what we experienced together with someone, it is like glue. You're the only two people in the world who can understand."
Meanwhile, the actor insists he'll never forget the call from Miley that alerted him to the fact their home had been destroyed.
"At about 3 or 4am, I got a call from Miley. She'd found out from a friend, and that was when she told me it was gone," he said.
He managed to save the most important things, but there is one possession he still wishes he could have picked up - a Rolex watch given to him by producers at Lionsgate after the release of the first "Hunger Games" movie.
Liam also opened up about potentially starting a family with his new wife, insisting he and Miley aren't ready to become parents: "You couldn't bring a baby into our house right now, but one day, we'll know when it's right... (We'll have) 10, 15, maybe 20 (kids)!".