Research released by Cuprinol ahead of the Shed of the Year competition, reveals that more than 14 million people in the UK now own a shed.
The figures suggest that 9% of shed owners store unhealthy snacks in their sheds, 8% hide cigarettes, while 4% keep love letters from ex-partners and 11% make secret phone calls from their sheds.
The research also shows that one in five shed owners spend time in their sheds to avoid their partners and that the average person spends almost a year of their life in their shed.
Shed owners are also bringing their sheds into the 21st century, as 35% of sheds now have electricity installed and 7% have a television.
Cuprinol's marketing manager, Kathryn Ledson said: "It's clear the nation are fanatical about sheds and view it as an important extension of the home, with many using it as a secret getaway to store secrets or avoid loved ones."
Cuprinol sponsors the annual Shed of the Year competition, which is organised by Reader Sheds and is now in its fourth year.
Sheds can be entered until May 5 at www.readersheds.co.uk.