Bob Stupica, a plumber in the Chicago area, has bailed out weekend DIY warriors countless times. “There have been some unusual problems, like the time a guy connected his toilet to a hot water line. Talk about being on the hot seat! But, for the most part, there are some common mistakes that I see all the time,” said Stupica.

The good news: He believes most weekend warriors can dodge typical problems with a little forethought.

Lack of planning

With YouTube and other online resources, many DIYers can get overconfident in what they can accomplish. “They’ll jump right in, thinking they will figure it out as they go. Rather, they should take the time to walk through the entire process before they begin. They should have a plan for each contingency they may encounter,” Stupica advised.

Forgetting to turn off the water

Virtually everyone remembers to turn off the water to the house as they start a plumbing project. But, Stupica warned, “Over the course of the project, the water can get turned on and off repeatedly as the project is tested. Sometime during this activity, the homeowner can forget to turn it back off when he or she goes back to work. Boom! You can end up with a real problem.”

Running out of time

They are called “weekend warriors” for a reason. Their projects are usually done over one or two days. “But it’s common for these projects to take much longer than planned. And, when they are out of time and their family is out of water, we get a call in desperation.” Stupica recommended budgeting twice as much time as you think you need just to be safe.

Using the wrong tools

Stupica sees DIYers try to use only the tools they have on hand for plumbing fixes. This can lead to bad connections and damaged fixtures. He advises homeowners to get the right plumbing tools for the task and learn how to use them properly. He noted that plumbing supply houses and tool rental stores can help people get what they need and also demonstrate how to use the tools.

Not remembering how to put things back together

Taking connections and fixtures apart often goes quickly and smoothly. But putting them back together can be a different story. Repeatedly trying to solve the puzzle is a huge time waster. And if you put things back incorrectly, there could be drastic repercussions. “A great practice is to continually take photos with your cellphone throughout your project. This way you remember what you have done and how things go back together properly,” Stupica suggested.

Using too much muscle

Stupica has covered for many he-men who love to really torque down with a wrench, leading to split fittings and striped threads. He recommended tightening with your hands and then using the wrench to snug things up with no more than a quarter turn.

Not knowing when to call it quits

When things go wrong, know when to call in reinforcements. Compounded mistakes can lead to spending even more money when you need to bring in a professional.

Said Stupica, “I hope you don’t have to call me. But, if you do, I hope you call me before things get too far out of hand.”