We have sewage plumbing insurance with the city, and after some back ups we called them up and a plumber came over. He said repeatedly there was an issue with the water trap, that he suspected there was a third one buried under the floor, and this was a one-inch pipe, which is not the four-inch accepted by the city. I had a feeling he was full of shit because I personally was involved with the building of this house and I never saw a water trap where he was indicating, and this entire set up was approved by the city inspectors; we would not be allowed to move in otherwise. So our contractor called a plumber he knew, who proclaimed it was a root problem. He also said it was impossible for us to have a one-inch pipe because his 1.5-inch-diameter camera would not have fit into it otherwise.

People are distrustful of plumbers, maintenance men, electricians, and the like because they often don't have the knowledge to dispute their claims and are at the mercy of their trustworthiness. I personally don't think I've been lied to, but the whole affair made me less faithful in these people's abiltiies. It's not just this incident, but others all along the construction project: the AC units, the gas, the electical wires... This isn't like an English class where everyone has their own opinion that's hard to dispute. This is engineering and science that should have some sort of definite answer. What the fuck is causing my plumbing problems. I should not have two completely different answers.