Fitting Lino / Vinyl in Bathroom - Underlay?

We will be fitting either lino or vinyl in the bathroom once it is all fitted, whichever it will be a sheet-flooring material.

What is it that is recommended to use under it to remove any irregularities in the floor? I dont' want to board the floor as it is already fairly flat as it's constructured of large sheets of tongue and groove moisture resistant chipboard.
I'm just looking for something to provide some level of cushioning, for comfort, noise supression and so that I don't end up in 6 months with visible marks on the meterial where it has a screw head / nail / join in the chipboard flooring below.

I was thinking of something like this (2mm foam underlay);



It is intended to go under laminates, but I wondered if it would give the desired result under vinyl?

Thanks

Vinyl or cushionfloor is designed to be fitted straight to the floor. Underlay of any type is not required and may cause the vinyl to "move". Note it should not be glued down either, although double sided tape is sometimes used.

To get the best out of this type of flooring the floor should be smooth and blemish free - any surface imperfections will eventually "show through"

If your floor is "gappy" or "lumpy" then you will have to board it out first. Use plywood of 4mm minimum and ideally 6mm thickness. This should be secured with ringshank nails fixed every 150mm in all directions. Size your nails so that they do not go all the way through and be aware of cables and pipes that may be below.

You also mentioned "lino" - Although this product is still available, it is rarely used these days in fact most fitters have "forgotten" how to fit this product, so it is best avoided!

Ok cheers.

The main flooring is actually T&G waterproof chipboard, so I'm not sure that covering it with ply will really produce any less gaps or 'features'...
Perhaps I should just buy some kind of filler to go over nail / screw holes with?