Every bedroom in Victoria should have a smoke alarm, according to overhauled fire safety advice.

The new advice, to be announced by the Metropoltian Fire Brigade and Country Fire Authority on Thursday, follows revelations that most fatal blazes in homes over the past 10 years started in bedrooms.

Many were avoidable, with just one in five Victorians sleeping with a smoke alarm in their bedroom.

A new advertising blitz will also be launched on Thursday. Credit:MFB and CFA

"Many of the house fires we attend occur overnight, often at a time when people are asleep," said interim MFB chief officer Greg Leach.