You've probably had the experience of opening a can of liquid and finding that you need to make two holes in order for the can to drain well. That extra hole lets air come in to the can to replace the liquid, allowing the pressure to escape and enabling the can to drain a lot faster. Your plumbing system works in a similar manner. In order for liquid (and sold waste) to flow down your sewer pipes with ease, your system needs a "second hole" which comes in the form of a plumbing vent.
Most plumbing vents are found on the roof. They look like little towers -- either round or square-sided -- and usually with screen-like caps on top. If you've been noticing odors and gurgling coming from your drains and toilets, there's a good chance there's a blockage in the vent, resulting in the sewage not flowing freely. Here's a closer look at this problem.
How do sewer vents become blocked?
Sewer vents can become blocked in two main ways. Material can enter the vent from the outside and cause a blockage, or it can enter from the sewage pipes. When the material comes from outside, it's usually either leaves, a birds' nest, or snow. When the material comes from inside, it may be toilet paper, other paper products, or a toy that your child flushed down the toilet. These items may initially clog the sewer pipes themselves, and then get pushed up into the vent pipes by increased pressure caused by the clog.
Can you remove a blockage yourself?
If the blockage originated on the outside, you may be able to alleviate the issue yourself -- as long as you're confident climbing up onto the roof and can do so safely. First, look at the top of the vent. Make sure there are no leaves stuck to the outside screen. This is a simple issue that can cause pretty serious sewer problems but that is really easy to fix. Just sweep the leaves away with your hand. If snow is covering the top of the vent, just move it.
If there is no visible blockage right on the outside of the sewer vent, remove the screen from the top of the vent and use a flashlight to look down into it. If you can spot something blocking the vent, you may be able to reach down with a hooked wire and pull it out. If this does not work, or if the blockage is too far down, you'll need to call your plumber.
How will your plumber remove the blockage?
If your plumber needs to come remove the clog, they can do so with a pipe snake -- the same tool they would use to remove a clog from your actual sewer pipe. They send the snake down into the pipe from the roof, and rotate it to ensure it grabs onto the clogging material. Whether the material originated outside the home or from inside the sewer pipes, this method should remove it.
How can you prevent future sewer vent clogs?
Make sure the top of your sewer vent pipe is indeed covered with a screen. This keeps leaves and other items from ending up inside -- though you may still need to sweep the wet leaves off the screen occasionally. Also, ensure your sewer vents are tall enough that they do not become buried in snow. If yours is frequently becoming snow-logged, consider having your plumber extend its height. Make sure nobody in your home flushes baby wipes or feminine hygiene products down the toilet, as these can create clogs that later move up into the vents.
Visit a site like http://www.rkknightplumbing.com for more suggestions.