laying vinyl floor - underlay?

[shirt]

I've layer floor tiles in the downstairs bathroom but for various reasons (time, having to lay a thick substrate, room shape) I want a vinyl floor in the one upstairs.

can I lay it on top of carpet underlay? I'm using 10mm PU everywhere else and it'll be nice to use the same.

also, what do you use at the edges in place of carpet grip?

[Simpo Two]

I think vinyl on carpet underlay would feel very strange. It's normally just glued down flat.

[shirt]

I've seen it done. strange yes, but good with it. think 10mm may be too much though!

[Simpo Two]

I wonder if it would tend to 'walk' and come away from the edge at one side?

[shirt]

what if I glue a thin underlay to the floor then the vinyl to that? floorboards not good enough for a direct vinyl lay and the hardboard I've tacked on hasn't made it much better. underlay is an idea to disguise that.

its going on the market in march, not fussed if it walks in future!

[steve2]

you may find that you will get a hole in it very quickly, hardboard should smooth the floor out.

[Simpo Two]

If the floorboards are so uneven, what about whizzing a planer over it?

[jeff m]

I don't understand why your hardboard isn't ok.

1/4 ply nailed. Nails sunk.
Skim with mud to cover nail holes and ply joints.

If you lay direct on floorboards the joins of the floorboards will soon appear in your vinyl.