Hi guys..I have a guttering union joint leaking and after pushing the guttering back into the joint several times over the past few yrs I think now the joint is probably knackered as it seems to leak now even when pushed back in so I need to replace it but I do not want to remove the existing faulty one till I have the new replacement at hand..question is how do I measure a union joint? To make sure I get the correct sized replacement ?..the current one is the semi circle type...many thanks for any advice /help