Plumbing tasks are more challenging than many people would like to admit. Many DIY projects do not go according to plan, especially when done by individuals without experience. When someone tries fixing their home's pipes and drains for the first time, they tend to make mistakes that can be hard to detect and costly to correct in the long run. This is why people should know the various DIY plumbing mistakes and avoid them. Using liquid drain cleaners instead of tools Many DIYers use liquid drain cleaners in excessive quantities to clear blockages from the kitchen or bathroom sink. While these cleaners may be effective sometimes, one should avoid using them because they can harm metal traps and pipes. There may also come a time when one may have to hire a professional plumber to remove the trap arm and fill it with a corrosive caustic drain cleaner, which is a tougher task than just clearing an obstructed sink. So, instead of making this mistake, one should simply use a snaked or barbed drain cleaning tool to clear blockages from their sink. Wrapping thread tape backward or using the wrong tape Thread tape must be wrapped clockwise around the threads to work correctly. Unfortunately, many DIYers wrap it backward, causing the tape to unwind from the threads as they tighten the fitting. Besides wrapping the tape correctly, one must use the right tape. Buying yellow gas-rated tape is recommended for threaded gas line connections. Moreover, one must never use threaded tape on flare or compression fittings. Over-tightening plumbing connections People often inadvertently damage their pipes by over-tightening the elbows, tees, and coupling. Over-tightening creates an excessive force in the pipeline, and it can crack when water flows through it. The problems will not be apparent immediately but will be seen in the long run. If one has over-tightened their connections, they can simply call a professional to loosen them up or use other solutions to reduce the force in the pipeline. Another common plumbing mistake DIYers should try to stay away from is greasing the elbows too much in the plumbing connections.