You can fix most household plumbing repairs and even update plumbing fixtures with just a few special tools and a little elbow grease. The work isn't physically challenging. But you do have to know the differences between the many types of pipes, fittings, glue and solder because that's one big area where DIYers often mess up. In addition to not using the right parts, DIYers also make these other common mistakes. Here's how to avoid the top 10 most common plumbing mistakes and get the job done right.