Are you trying to say that shielded cable gives better protection against moisture?Yeah, you should have just left it as yogi was trying to help you out.
He's putting it outside, there will be moisture in the air, even if you put it in the piping. At that length, one would rather install it once and forget about it rather than having to swap it out after a couple of years, especially as the price difference is maybe R100 at that length. I doubt you'd even find unshielded unless you buy per meter and splice it yourself. At that length, your cable will be more prone to interference as well, but if he's burying it in piping it should be fine.
You can find outdoor UTP cable like this: https://scoop.co.za/download/linkbasic/UTP-100.pdf
