Can anyone recommend a better method of affixing UPVC (e.g. Homelux) floor trims to skirting other than the adhesive tape provided?
Can you mechanically affix them or is it just down to adhesives?
I don't like liquid nails as it dries out to no bond in 10-years or less & prefer Lock-Tite "caulks". But yes, you can nail that stuff. You'll need to pre-drill it (or it will split & explode) for the shank & for the nail head, since you're drilling & filling anyway you may prefer to screw it like I do.
If you mean plastic roll wallbase:
Use Liquid Nails or go with real trim.
With the "adhesive tape provided" ? Don't you mean 'the provided adhesive' ? If it comes with a roll of tape it's not the good stuff (if you want to call it that...) If it is the good stuff, with about an eighth inch of goo on its entire backside, what you did wrong was improper surface prep (scarify the surface and then clean it with alcohol). I've never put this stuff in but when it's done correctly, it does NOT come off without destroying the wallboard.
Try not to buy old stock and don't install it when it's cold.