Your bathroom has a plumbing problem, and you feel confident enough in your DIY dexterity to confront the issue on your own without a professional plumber. Before you get started, we recommend familiarizing yourself with a few important things — like what not to do.
 

The alternative? Risk making a mistake and wind up paying a plumber to do the repair anyway, which will set you back at least $45 per hour depending on where you live and the experience level of the plumber.

Here are nine bathroom plumbing mistakes to avoid when working on your sink, shower, tub or toilet.

Forgetting to Put Traps on Drains

You know the U-shaped curve in your drains? Those are called traps, and sometimes DIYers make the mistake of not using them, says Terry O'Shea, a plumbing manager for Roto-Rooter in the greater New York City area.

A lot of homeowners, he says, assume the trap is there to make it easier to retrieve items that are inadvertently dropped down the drain. However, the trap is actually there to prevent odors from sewer gasses from entering your home — so you absolutely don't want to forgo it.

Overtightening Your Connections

It might seem logical that the tighter you crank your plumbing connections (pipes, coupling and joints), the more likely they'll stay put and not leak. Not so, says Aaron Mulder, co-owner of Mr. Rooter in San Antonio, Tex.  In reality, he says, if you take the tightening too far you will actually cause your fittings to split or even rupture.

Mulder suggests making sure fittings are snug, but not tight. A good rule of thumb is: For slip joint nuts and flexible supply lines, finger tighten and then tighten an additional one-quarter to one-half revolution. You can always tighten the joint a little more if it leaks.

Forgetting to Turn Off the Main Water Line

We know you are eager to get going on that bathroom project. But you should never even start a plumbing project before turning off the main water line to your home. (The location of your main water line valve depends on where you live and whether you are on city water or a well). The disastrous potential consequences? Flooding! Avoid the troublesome and expensive cleanup by doing this quick-and-easy task first thing.

Note: Many sinks and toilets have shut-off valves located near the fixtures that allow you to make repairs safely without turning off water to the whole house. Know where your main shutoff valve is located and test it to make sure it's working before starting any plumbing repair. This way, if your fixture shut-off valve leaks or you run into some other problem requiring you to close the main water supply valve, you'll be prepared.