There's no such thing as a good sewer odor, right? If there's a persistent, but unexplained, stink emanating from your bathroom the cause could be sewer gas. Sewer gas is supposed to stay down inside your municipal sewer system or private septic tank. Problems occur when it finds its way back up into the house via your toilet. Eeew.

Surprise, surprise. Plumbing experts say sewer gas is something you should take care of, and not just for the obvious reason that the stink is absolutely revolting. Did you know that sewer gas is toxic when breathed in repeatedly? It's also associated with a buildup of methane gas, which is explosive. Eeek! Now that's a potty problem!

According to trusty home repair extraordinaire, Tim "Ask the Builder" Carter, it's best to locate the root cause of the problem as soon as possible. Tim says the cause of the stink is usually a blockage or a crack in the plumbing drain line or vent pipe, with the latter being a lot harder to detect. Plumbers can find the leaks by forcing colored smoke from a smoke generating machine through the pipes. Cool!

Read more at AskTheBuilder.com.