Good answer @Marg19, you beat me to it.
I was looking at laying vinyl planks in an extension rennovation I'm currently undertaking. At the end I was put off as this will be going over a number of different sub floors including existing hardwood floorboards. I was worried about the shadowing that may eventually come through as the floorboards arent even and the time / effort and cost of sanding these back has pushed me to look at other options.
My lazy-butt thought would be to put down a thickish floating floor underlay, before installing the vinyl boards. But there's an if, the tiles need to have been laid well, that being the surface is even, without any major irregularities.
To get an idea of how regular or bad the tile surface is, try laying a straight edge on top of the tiles, shine a light underneath, & look for how much light comes through.
If it's all over the place, lift the tiles as shown in kermit's link to the Bunnings vid, & lay the vinyl tiles as directed on the packaging.
If it looks good, just underlay & install.
Hope this helps
Thanks for replying. My tiles are probably around the same age, but look far worse. You have achieved a great look.
Thank you so much. Yes, it looks messy, but is certainly another option.
How are your renovations going?
We have a discussion on Workshop today that you might like to join as I recall you saying that you wallpapered your home. It would be great to see some photos of what you have done and read about your design decisions. The discussion is Would you hang wallpaper in your house?