any advise for laying solid wood onto concrete?

[Joiner_Mike]

Hi all
Hope you are all well.
Im just after some advise and helpful tips.
I am going to be laying a solid wood flooring onto a concrete slab. I am doing around 100sqm running into 4 rooms. I have decided to do this using the sleeper method using 2"x1" batons. I was thinking of doing it in this stage if you have any advise or tips please inform me
1) Re-check moisture content of slab again prior to fixing.
2) Lay blue visqueen sheeting on floor running up the walls 4" and taping with mositure proof tape, overlapping sheets by 6"
3) Lay 2"x1" battons 250mm centres overlapping instead of buttuting up end grains of 2 battons. Fixing with plugs and screws. Laying width of room.
4) Lay polystirene inbetween battons.
5) Fix flooring length ways using 40mm/35mm tounge tite flooring screws leaving expanson gap around all edges and cutting in doorways

If you have any advise I would be very greatful to recieve it. What expansion gap do u suggest, should i put in expansion joints at doorways and if so how?
I have choose batton method as its cheaper and the height isn't a problem as all of down stairs is getting done and all exterior doors have the space under the door for me to do this