Here’s how to test for plumbing skills

Nobody thinks about plumbing until it stops working. Then it's the only thing anyone can think about.

That's the odd position plumbers occupy. Their work is invisible when it's done right and unforgettable when it isn't. Hiring for it has the same problem: a solid plumber and a shaky one can sound identical in an interview. A plumbing skills test is one way to tell them apart before anyone shows up at a customer's house with a torch.

The pressure to get this right is growing. Bloomberg reported that the U.S. could be 550,000 plumbers short by 2027, according to NewsNation's summary of that reporting. That's an estimate, not a census, but the direction is hard to argue with. Bloomberg Businessweek's March 2024 coverage, as recapped by Mechanical Hub, pointed to the same problem. Young people are shying away from work that's physically demanding and sometimes messy, even though it pays well.

When candidates are scarce, the temptation is to hire the first person who says the right words. That's exactly when verifying skills matters most.

Here's the catch. "Plumber" on a resume can mean a licensed journeyman, a service tech who's mostly swapped fixtures, or someone who spent two years as a helper carrying pipe. Interviews don't sort these out easily, either. Trade vocabulary is learnable, and confident talk about flux, fittings, and venting is not proof someone has installed a system that passes inspection.

The state of the plumbing workforce

Start with how people get into the trade. Most plumbers, pipefitters, and steamfitters learn on the job through an apprenticeship, and most states require plumbers to be licensed. Per the Bureau of Labor Statistics, that training can run four to five years. You can't add capacity quickly when the pipeline (no pun intended) is that long.

The demand side isn't slowing down either. BLS projects employment to grow 7% from 2025 to 2035, with about 42,000 openings a year. The median annual wage was $63,800 in May 2025. Most of those openings aren't new jobs. BLS says many come from workers transferring to other occupations or leaving the labor force, such as to retire.

The retirement piece matters because experience walks out the door with it. Reporting on the skilled-labor gap notes that more than one in five construction workers is 55 or older, and that the departing tradespeople are often the most experienced. So employers are increasingly hiring people earlier in their careers, and judging how far along someone really is gets harder.

What a miss costs

Not every leak is a hiring mistake. But the stakes of plumbing work are easy to see in insurance data. According to Triple-I data reported by This Old House, water damage and freezing made up 22.6% of all home insurance claims in 2023. Only wind and hail claims were more common. The average water damage or freezing claim from 2019 through 2023 was about $15,400.

Those claims have many causes, from storms to frozen pipes to worn-out appliances. Water gets into places it shouldn't, and cleanup is expensive. A plumber who misjudges a material, a system requirement, or a joining method can turn a routine job into a call-back, or worse.

Ideal industries and jobs

The Plumbing (U.S.) assessment is useful anywhere pipes, fixtures, and water systems need to be installed, maintained, or repaired. According to BLS occupational data, most plumbers, pipefitters, and steamfitters work for contractors, but the need extends well beyond them.

Plumbing and mechanical contractors

Service and install companies can use the test to sort applicants by readiness before deciding who rides along with a senior tech and who can run calls independently.

Construction

General and specialty contractors hiring for new builds and renovations can use it to check that applicants understand the materials, components, and system requirements behind rough-in and finish work.

Facilities and property maintenance

Hospitals, schools, hotels, and apartment portfolios all have a plumbing system that has to keep working. Maintenance hires often need broad plumbing knowledge, not just a general "handy" résumé.

Utilities and municipal services

Public works and utility employers can use it as a structured checkpoint for field technician roles.

Representative job titles:

• Plumber / journeyman plumber
• Plumbing apprentice or helper
• Service plumber
• Plumbing installer
• Pipefitter
• Maintenance technician
• Facilities maintenance worker
• Building engineer

What does the Plumbing Skills assessment cover?

When you hire for plumbing, you're really asking two questions. Does this person know what the work requires? And can they make sound decisions when a job doesn't match the textbook?

The test covers these subject areas:

• Equipment Installation
• Piping Materials
• System Components
• System Requirements
• System Types
• Tools

These map to real decisions. Choosing the right pipe for the application, knowing how components fit into a larger system, understanding what a system needs to function properly, and using the right tool the right way are the building blocks of most jobs. Weakness in one area tells a hiring manager where to probe in the interview. It can also show where a promising candidate may need some training.

Test format

The Plumbing Skills test consists of multiple choice, select-all-that-apply, and true/false questions. Test builders can choose from among 40 questions, and add questions from other test categories (or write their own) as well.

Complementary questions

Plumbing rarely lives in isolation, and eSkill assessments can be customized by combining subjects to fit the role. Here are subjects to consider pairing with the plumbing skills test. 

• Blueprint Reading: Plumbers work from plans. This test covers topics including Mechanical Systems and Sitework, Grading, and Site Utilities.
• HVAC: Useful for mechanical and maintenance roles where plumbing and heating/cooling overlap.
• Welding Knowledge: Helpful for pipefitting or industrial roles where joining methods extend beyond the basics.
• Units and Conversions Skills: Measurement and sizing mistakes are avoidable ones.
• Basic Math: A quick check on the everyday calculations behind materials and layouts.
• Attention to Detail: Small oversights on a pipe run have a way of becoming big ones.
• Environmental, Health and Safety: Worksite awareness matters for anyone going into crawlspaces, trenches, or mechanical rooms.
• Critical Thinking Skills: For diagnostic and troubleshooting roles, where the problem isn't always where it first appears.
• Electronics: For maintenance roles that touch pumps, controls, or other powered equipment.
• Customer Service: Residential service plumbers spend their days in other people's homes, so how they communicate matters.

For a residential service plumber, for example, you might pair Plumbing (U.S.) with Blueprint Reading, Attention to Detail, and Customer Service. For a facilities maintenance technician, consider Plumbing (U.S.), HVAC, Electronics, and Environmental, Health and Safety.

Why use a plumbing skills test?

Plumbing skill is hard to verify through a resume and a conversation, and the cost of guessing wrong is real. A plumbing skills test gives you a consistent way to check what candidates know, under the same conditions, before you commit interview time.

A few practical benefits:

• Look past titles. Two candidates with the same job title can have very different knowledge. A test helps you compare them on the same footing.
• Screen more consistently. Every applicant answers the same questions, so you're not relying on who interviews best.
• Spot trainable candidates. Strong results in some areas and gaps in others can point to someone you can develop, which matters when experienced plumbers are hard to find.
• Make interviews sharper. Results give hiring managers specific areas to ask about, such as piping materials or system requirements, rather than generic questions.
• Reduce rework risk. While no test can guarantee a hire's performance, checking core knowledge up front can help you catch gaps before they turn into call-backs or training surprises.

Testing works best as one input alongside structured interviews, license verification where required, and hands-on evaluation. It supports your judgment. It doesn't replace it.

Letting it sink in

The plumbing trade is getting older, demand for skilled people isn't going away, and every new hire carries more weight as the talent pool tightens. Employers who can reliably tell who has the knowledge and who is bluffing will be better placed to staff their crews. A plumbing skills test is a practical way to start.