It's been called many things -- the loo, WC, the lavatory or simply, the toilet. Whatever you may call it, one thing is certain -- life would be pretty unbearable without it. When something goes awry with your porcelain throne, plumbers can be called in to fix the problem. But a plumber's job goes way beyond unclogging toilets. Plumbers do everything from installing piping systems and fixtures to ensuring compliance with building safety standards.