laying junkers floorboard

[dents]

i am laying junkers oak wideboard ,20.5mm thick in the living room which is above a cellar.

as an underlay i am using polylay which has a dpm (bought by mistake i think as just a dpm would do) also i am using the felt type underfloor boards 7mm thick laid at 45 degrees .

i will be secret nailing the boards,,but i would like to hear comments if you think i am going over the top with my preps for the oak boards.

also would it be wise to follow the same board direction as the excisting ones or go in the direction of the joists which would look better for appearence.

should i have done a floating floor? or will it be ok to do what i plan and have already started?

would be interested to know what you think
oh and which way up do the underfloor boards go ? :lol:
cheers

dents