Well that's re-assuring - maybe I'm being too concerned. Because of this have barred this WC for big jobbies (there are others in the property!).It`s not an issue that will actually cause a problem
Hugh, if the join can't be undone, splicing the section is an option but something I really would like to avoid.
My builder put that tile under the join (in the first pic) and flexed the pipe at the bend going down and this provided at least some incline in that section. But to stay in that position he says would require a bracket to brace against that bit of chimney on the outside face. Apart form the fact that I don't want him to endanger his health doing that (he says not to worry but it just looks difficult to manage), it would also put continuous stress on the whole length. So, going by Nige's re-assurance, if I can leave everything as is and not worry about it, that would be great - or else it's the splice