Should we use Varnish, Oil or Wax on new Radiata Pine Staircase Kitchens, doors, rails, stud, tables, chairs, stair cases, garden furniture etc... Find answers and ask questions here!

[Hinckley Hammer]

I've just had a new radiata pine staircase fitted and need to know what the best treatment would be to preserve and protect it. Would this be Osmo? varnish? Or a wax type treatment? Thank you.