Recently moved overseas to a country that doesn’t have wood stud walls to hide pipes in. As a result, they don’t separately vent fixtures but depend on the main vertical drain riser to be vented. I am installing a bath with 2 branch lines. 1 for the toilet which will be only 2 feet from the vertical riser. And, 1 for the shower, lavatory, laundry sink, floor drain, and washing machine drain (max. run 10 feet). Have been advised locally that I don’t need additional vents at each location. I am skeptical, but don’t know where to run the vent pipes except to use a Studor vent or surface-mount the vents to the wall. All locations will be trapped. Any predictions as to the performance of drains and traps and back-siphoning? I am very interested in everyone’s opinion of this. Don’t even ask about code inspectors here. I have yet to hear of their existence here.
Drains of Malta. Can’t advise you of the regulations cause you didnt mention the country but you have alluded to Malta. I have seen some pretty weird plumbing in my day & most work. The only advice would be – When in Rome – do as the Romans do. you might learn something. Bob