Solar PV on a corrugated roof - help

Hi All
I need a bit of advice on fitting PV on a corrugated roof.
The roof is 4x2 timber with stirling board which i think is 18 or 2mm. The board is then covered with corrugated sheets. There corrugated sheets are black and seem to be pvc or some thing similar. Im not an expert on this type of roof so i'm a bit concerned about penetrating it when fixing the rails for the PV.
I intend to fit the rails with hanger bolts which have sealing washers http://www.segen.co.uk/Installer/Product/1789/Hanger_bolt_200_20
I was thinking about putting a flashing tape on the roof before fixing the hanger bolts.
I'm concerned about water penetration. Does this sound ok to you guys?

Thanks in advance