Vapour barrier needed under floor?

[Screech20]

Get guys,

This is the log cabin we're currently putting up.

I'm going to put 60mm insulation in between the bearers before the floorboards go down.
Should I put down some kind of vapour barrier? If so, on top or under the insulation?
Cheers[/b]

 

[Screech20]

Anyone?

Hoping to get the floor down over the weekend.

Cheers