Thanks for the advice however I have ordered the skirting already and it is not MDF but solid wood with a walnut veneer. I have no intention of painting or staining it ever, as I simply wouldn't have the time for it, hence the choice of pre-finished (talking 200m of skirting).
Having said that I have done a little test on a piece of skirting and I can actually sand it slightly (it is a layer of"real wood" veneer) so should be able to touch up and varnish if required or add moisture protection on the few lengths of skirting I have where I have tiles. But I think as the veneer is wrapped around the timber I don't see how moisture would penetrate.
I have had unfinished untreated (due to fact I had no time to ever stain it) pine skirting in my kitchen and with all the floor washing I have done there I have not seen any effect on the look of the skirting, so am not really concerned.
But I would like to stay on topic and would welcome any suggestions on specific techniques for installing or any realistic estimates on the cost of installing per foot.