Underlay then Ply

[DorothyMantooth]

Hi folks,

Ive decided to forego 2 sheets of ply on my westy floor (9mm and 6mm) and go with a single sheet with thermawrap underlay.

Does anybody roll with this? Is there any bowing \ dip in the ply?

Which underlay is popular? I've access to b and q and screwfix however most of the underlay does not mention if it is closed cell or not which is why I thought that thermawrap would do the job

Cheers!

 

[Supertramp]

Can't imagine this will work? When I put the 9mm down I had some spare underlay underneath just to protect the floor and the 9mm dipped in various parts.