Plumbing is a complex task requiring both precision and knowledge. Page through any city phonebook, however, and you’ll find a host of plumbers claiming they do work not just fast, but cheap.

Unfortunately, some are in the business just to make a quick buck and aren’t shy about running a scam! Here are four of the most common plumbing scams … and how to avoid them.

The ‘Three Dressed Up as Nine’

This scam revolves around materials. High-quality, cross-linked polyethylene (PEX) piping or copper tubing comes with a high cost, and many homeowners aren’t shy about shelling out for products that will keep a home’s plumbing in good condition for the next decade. Unscrupulous plumbers, however, tell you they’re using only the best materials, charge you as if they were and then use lower-cost alternatives.

There are two ways to beat this scam. First, ask for a list of parts your contractor plans to use, then take the list to your local hardware or home-improvement store. If the plumber is using high-end materials but overcharging, call his/her bluff. If she’s using low-end products but making a massive profit, find another contractor.

Second, check to make sure what’s on the invoice matches what’s behind your walls. If your plumber says she’s using a particular brand of PEX tubing, examine it before installation and make sure she isn’t trying a bait-and-switch.

The ‘Busy Beaver’

For this scam, your plumber sets to work as soon as the ink dries on his contract, but within a week you notice there are more people in your home than necessary. In some cases, “extra” workers may be apprentices, but some contractors try to ramp up their profits by subcontracting parts of the job they could finish themselves out to friends or family, and then claiming they have no control over hourly rates except their own. 

Always ask exactly why each person is needed. If you aren’t sure who’s doing what in your home, stop the work and make sure extra costs aren’t being incurred from unnecessary labor.

The ‘Golden Spoon’

If you live in an affluent neighborhood, you may be getting overcharged. Plumbers aren’t required to have a fixed hourly rate, meaning they can charge whatever you’re willing to pay. Some contractors who see nice cars in your driveway, a hot tub in the backyard or a high-end flatscreen TV in your living room may assume you have deep pockets and will up hourly rates by as much as 50 or even 100 percent.

The ‘Evasive Estimator’

This guy is a smooth talker. Everything you want is “no problem” and he’s keeping a “running total” of costs in his head as he moves through your house. When you ask for an estimate in writing, he says he needs to sit down and itemize everything and that he’ll get back to you.

When he does, he’s offers a great-sounding final budget, but only over the phone — there’s no paperwork. He promises you’ll see some paperwork right away but seems eager to get to work, so you let him. Weeks go by, and still no paper estimate. But when the job’s finally done, you get an invoice at two or three times the original price and no sympathy from the contractor when you protest. 

Always get a quote in writing and sign a contract specifying how much will be paid, and when. That way, if the quality of the work is suspect or the job doesn’t get done on time, you have a fighting chance in civil court.

How to Identify a Scam

The easiest way to avoid plumbing scams is always hiring a reputable professional. But how do you tell him apart from scammers? Start by asking questions — lots of questions. If she wants your business, she shouldn’t mind answering and should be willing to produce his/her license and business registration on demand.

Too many homeowners worry about being polite instead of to the point: It’s your money, your house and you’re the one who has to live with the results. If a contractor gets offended or angry about your demands for high-quality work and written estimates, she’s a scammer, plain and simple. Know your budget and know your rights.