Bathroom Floor

[BazzaS]

We currently have carpet in our bathroom and wish to replace this with vinyl flooring.
Under the carpet we have a mixture of floorboards and chipboard floor panels - all quite level.
I'm OK with DIY but have never tackled a job like this.
I intend to leave the toilet & pedestal in place and work around them.
Having removed the carpet/underlay do I need a damp proof membrane of any sort ? If so what sort ?
Do I need to lay a hardboard/ply base 'floor' ?
Help please - all advice gratefully received.
Baz

 

[foxhole]

Hardboard is ok for vinyl flooring unless uneven in which case ply would be better.Vinyl is waterproof so no membrane required, seal around all cut edges with silicon.