Talk to others. Ask people you know whether they've had completed a similar project recently. You'll need as much information as possible about the plumber. Find out whether they are licensed and insured. How long have they been in business? More information is better than less. The goal is to find a good plumber who is competent, reliable, and responsible. If you can, find 3-5 plumbers. If your network doesn't provide enough leads, consider checking with Angie's List. A link to more information about Angie's List is below.
Make sure the plumber is licensed. Those states that license plumbers keep lists of licensed plumbers. Most states require that all contractor advertisements, whether they're in an ad, the phone book, a newspaper, or on the company truck, must include the contractor's state license number. The Angie's List offers members a list of web sites by state and contractor category where you can check the license status of potential contractors, including plumbers.
Consider Using Angie's List [http://angies-list-details.synthasite.com/]. Angie's List uses technology to take the "ask-your-neighbor" approach to a whole other level. They screen 40,000 reports per month from their 750,000 members nationwide. The members report on recent use of plumbers and many other types of businesses. This service can make it easier to find a good plumber. These reports are the basis of reliable, unbiased information on local companies for consumers across the country in major cities. While Angie's List is a great tool, it shouldn't be your only tool. Make use of the resources available from your local building department, consumer protection agency, and the Better Business Bureau.
Look around before hiring a plumber. Reduce your list of plumbers by using the process above. The goal is to hire only the best. Then ask for written bids - a minimum of three should be sufficient. Be sure to comparing the bids based on identical plans, specifications and scope of work.
Beware of any bid that is considerably lower than the others. The plumber may have made a mistake. If you accept a low bid, they may have to cut corners or do substandard work to make a profit. Also beware of unlicensed plumbers. While they may offer a low bid, the risks of poor quality work and of financial and legal consequences far outweigh any benefits a lower bid may seem to offer.
Confirm that the plumbing contractor has the legally required insurance coverage. In most states this includes both workers' comp and commercial liability coverage. Ask for either the name of their insurance carrier or for a copy of their certificate of insurance. Either way, you need to verify their coverage. Any good plumbing contractor should be able to provide you with this type of insurance information quite easily. Beware of plumbers who cannot.
Most states require contractors to carry workers' comp coverage if they have employees. If they don't, and an injury to a worker occurs on your property, your homeowner's insurance may not cover it. That means you would be liable to pay for injuries and rehabilitation. Verification of the plumbing contractor's insurance is a small effort that can reduce your risk considerably.
The steps above provide a number of resources and, more importantly, a process, to help you find a good plumber, In addition, you will become more knowledgeable and reduce your risk of being victimized. This process will help you uncover the information you need to make an informed decision and find a good plumbers.