laminate with underfloor heating 1st time

[donmazzei]

HI guys and girls i need some help, am doing my conservatory with laminate flooring and underfloor heating just a bit confused on how to layers all work on a concrete floor

do i go with vapour barrier under the fibreboard then a 3mm underlay on top then the heating mat then the vapour barrier for the heating mat then the laminate

or do i go out and buy the proper thermal insulation boards then go

vapour barrier, thermal board, electric matt, vapour barrier and then laminate?

or have i got it all wrong ?

bare in mind already have some fibreboard a mate gave me and the underlay which was free :)

any help is muchos appricated :)

tony