plywood laid on old floorboards is squeaky

[jgkgolf]

I have old floorboards in my kitchen on which I have laid 16mm plywood as I want to put down vinyl. However even though the floorboards didn't seem to squeak , the plywood laid on top does no matter how many screws I put in! Is this a known problem with plywood? Is it possible to put something like carpet underlay between the ply and floorboards to stop the squeaking? Thanks, John

[Alex]

Have you included a expansion joint between sheet edges and skirting, most squeaking will beat at the edge of the board a cork strip would work, what type of ply have you used,

16mm seems a bit overkill, was the original floor boards secured before fitting

for a vinyl floor tempered hardboard would have been adequate