Engineered wood over parqet

[RoyByron]

Hello all,

I have some engineered wood floor to put down over a 1960's parquet floor. Not sure on if I need a DPM or not? The parquet is stuck down with Bitumen so my thought is that would provide a barrier?

The parquet is solid but just showing its age and as much as I would like to restore it, it's going to take far too much effort (to much effort to remove the bitumen) and it's a bit dark and gappy.

I was going to use these underlay boards from screwfix
http://www.screwfix.com/p/vitrex-premier-wood-laminate-underlay-boards-5mm-9-76m-green/68038
but as they are more of a 'hard' foam than a fibreboard I'm not sure if that is providing a barrier. Would fibreboard be better?

After a fair bit of time on google I am unable to find a solid answer to my question, any thoughts welcome.

Cheers

 

[RoyByron]

I should add it's concrete under the parquet

 

[dazlight]

There won't be a damp proof membrane under the old parquet but if solid you might get away with it. All depends on your water table.
If you go over you take a gamble.
You could take them up and put down a liquid DPM. But depends if you want to go that length