When you’re hiring a plumbing contractor, the most important qualifications are a current state license, liability insurance, and workers’ compensation coverage. Beyond those basics, look for verifiable experience with your type of project, a track record of transparent pricing, and reviews from real customers in your area. In Colorado, plumbing work above a certain scope must be performed by or under the supervision of a licensed plumber — so licensing isn’t optional, it’s a legal requirement that protects you.

Colorado Plumbing Licensing Requirements

Colorado licenses plumbers at the journeyman and master plumber levels. A master plumber has completed the journeyman level, accumulated additional field hours, and passed a more advanced exam. Most residential plumbing projects require a licensed plumber to pull a permit and oversee the work. When you hire an unlicensed contractor — even for something that seems small — you risk work that doesn’t meet code, inspections that fail, and liability issues if a problem causes water damage. Always ask to see a license number and verify it with the Colorado Department of Regulatory Agencies (DORA).

Insurance: Why It Matters More Than You Might Think

Liability insurance protects your property if the contractor accidentally causes damage — a burst pipe during a repair, water damage from a fitting that wasn’t sealed correctly, or a broken fixture. Workers’ compensation covers the contractor’s employees if they’re injured on your property. Without these coverages, you could be held responsible for injury costs or left paying out of pocket for damage a contractor caused. Ask for a certificate of insurance and confirm it’s current before work begins.

What to Ask Before Hiring

A few direct questions will tell you a lot about a plumbing contractor’s professionalism:

  • Are you licensed in Colorado? What is your license number?
  • Do you carry general liability and workers’ comp insurance?
  • Will you pull the required permits for this job?
  • Do you provide a written estimate before starting work?
  • What warranty do you offer on parts and labor?
  • How long have you been serving this area?

A reputable contractor answers these confidently and in writing. Vague answers or pressure to skip permits are red flags worth taking seriously.

Experience With Denver-Area Plumbing Conditions

Local experience matters more than it might seem. Denver’s hard water — high in dissolved calcium and magnesium from the Rocky Mountain watershed — creates mineral scale inside water heaters, on fixtures, and inside pipes. Contractors who work here regularly understand how to size water softeners, recommend appropriate water heater maintenance intervals, and spot scale-related damage that out-of-area contractors might miss. Similarly, Front Range homes face frozen pipe risk during cold snaps, and older Denver neighborhoods have a mix of copper, galvanized steel, and even some clay sewer lines — each requiring different approaches.

Reviews, References, and Track Record

Online reviews from verified customers are one of the most reliable signals of a contractor’s real-world performance. Look for patterns: do reviewers consistently mention arriving on time, giving accurate quotes, and cleaning up after the job? A handful of five-star reviews can be cherry-picked; hundreds of reviews over years of service tell a more honest story. Check Google, the BBB, and Yelp. Ask the contractor for references on larger jobs like repiping, sewer replacement, or water heater installation if the scope warrants it.

Pricing Transparency

A trustworthy plumbing contractor provides a written estimate before starting work and explains what’s included. Beware of contractors who give a low verbal quote and then add charges once the job is underway — a practice sometimes called “change order padding.” Flat-rate or upfront pricing, where you approve the cost before any work begins, is the standard you should expect. If a contractor won’t commit to a written price, keep looking.

Done meets every qualification on this list: licensed, insured, upfront pricing, and backed by decades of Front Range experience. Explore our plumbing services or contact us to schedule an estimate — and see our customer reviews to hear from homeowners who’ve been in your shoes.