The long-term couple, who have children Billy Ray, seven, and Nell, three, famously live in adjoining apartments in London and the kooky actress says Burton's 'deviated septum' and her 'bossiness' are to blame.
The 44-year-old told the Radio Times, 'Tim does snore, and that's an element. We've tried lots of remedies that don't work. He has a deviated septum and doesn't want an operation.'
But she said that far from being a disadvantage, the arrangement has actually helped their nine-year relationship.
'We see as much of each other as any couple, but our relationship is enhanced by knowing we have our personal space to retreat to,' she explained. 'It's not enforced intimacy. It's chosen, which is quite flattering if you can afford it.'