Problem to have DPM between floorboards and solid flooring?

[OscarLomax]

Hi, I want to fit 18mm solid flooring to old house with suspended floorboards and could do with some advice.

The original floor is flat and I've been told to directly secret screw the boards (oak) down.

I have also been told to use 3mm underlay between as it adds thermal insulation, but it has a built in DPM and I have ALSO been told 'NEVER put a DPM between floorboards and new solid wood floor'!

Any comments? I'm particularly interested in the DPM issue. The existing floor in well ventillated from below and the new flooring would, obviously, be well ventillated from above, so what's the problem?

Thanks in advance,

Osc

 

[freddiemercurystwin]

I have also been told to use 3mm underlay between as it adds thermal insulation

A 3mm layer will not add any thermal insulation. It may prevent some drafts which you may perceive as thermal insulation. You don't need a dpm between the boards.

 

[OscarLomax]

Thanks for reply, what about builders paper between flooring and boards? Or should I literally just screw directly to existing wood?

Also, I have also been told (by wood supplier) to glue & screw but I don't like the sound of that. I know it stops large sheets of T&G chipboard squeeking, but I don't think the glue is needed for T&G oak (??????)

Cheers!