insulating existing floors

[agencytart]

hi i have a victorian terraced house and i am on a mission to insulate as much of it as i can
my house has a mixture of solid (hall,kitchen & utility) and wooden(living room & dining room) floors
it is blessed with high ceilings so head clearance isn`t an issue, the floors are level and in good condition so i don`t really want to dig them up
my question (at last) is

Has anyone had any success with simply laying sheets of 25mm celotex or similar on top of the existing surface and laying a laminate or similar floor on top
this seems like a simple solution or am i missing something ?

 

[big-all]

if your talking 9mm laminate then then no as you need a structural timber normaly you would say 18mm minimum but you would probably be ok with 15mm as the foam will give some support

 

[agencytart]

i was thinking 1/2 inch ply so that might work
will the insulation suffer by being under compression?
i`m guessing the ply would spread the load
thanks for the advice

 

[big-all]

12mm should be fine
just remember all you skirtings will probably need replacing
your doors probably wont look good and will probably be weakend
they will certainly be beyond the normal 25 to 40mm manufacturers total removed from a door