There are other skills plumbers need aside from being able to work with water. One of the most common things that a water leak on is fixing water lines.
Visually water line repair examine the frozen pipe for signs of damage including cracks holes or breaks. Begin your quest in the areas that are located closest to cold area such as the outer walls and crawl spaces. The holes can be as tiny as a pinprick, so inspect the pipe closely.
After you have the stems out you should be able to find the washer on the "inside" end. If it is nicked, torn or brittle it is likely the cause of your drip. Even if it looks brand new, go ahead and replace it. You've already come this far. You can get replacement washers at almost any hardware store. Sometimes you may want to replace the whole stem, especially if the handle end is stripped out. It's best to just take the stem with you to the store and see if you can match it up. Most Do It Yourself stores have replacement stems for many popular brands. If your valve has a center diverter valve to switch the waterfrom the tub spout to the shower head the same process applies. Many times it is easier to replace the diverter stem than to repair it. This really depends on the design of the stem.
Clean the hole in the gutter railing first. It must be free of any debris, so you may want to clean the entire drain channel using a proper cleaner. In this way, you will have a clean surface area which will allow you to repair the hole more easily.
Keep an eye on any leaks in and around the house. Inspect taps, pipes and your roof regularly. Watch for leaks and if you find them, get it water line repair as soon as possible.
From your own point of view, it is important that the plumber be trustworthy and credible. Ensure the plumber comes with at least two strong references which you can verify. This will help you be more secure and suffer less anxiety.
By the time that you have made your pick, make sure to check ID and Certification. Remember, these individuals will be doing their works inside your home. The security of your family is also an issue here. If they can't present any papers of identification, then don't take them in! When it comes to your family's safety, there's no room for experiments.