Sink repair: a guide for pros

What customers ask, how to win the job, and what to put on your profile.

Offering sink repair

Sink repair is mostly a joint-and-washer job, and the callbacks come from a joint that was not checked under water. Find the leak source first, then replace the part that failed.

What customers ask

  • Why is the sink leaking under the cabinet?
  • Is the sink cracked, or is it just the trap?
  • Why does the sink gurgle when I run the other sink?
  • Can you stop the drip from the faucet without replacing it?
  • Is the water damage under the sink serious?

How to win the job

  • On the first call, ask where the water shows up, whether it leaks only when the drain runs, and whether the sink has been cleared recently.
  • Bring trap kits, slip nut washers, supply lines, shutoff valves, a cartridge kit and a flange kit to the first visit.
  • Dry the joints and run the drain while you watch, so you find the leak before you change parts.
  • Show the customer the failed washer or trap, and explain what failed and why.
  • Quote the parts and the labor as separate lines, so the customer can see what was replaced.
  • Test the drain under water and check the cabinet floor before you leave.

What to put on your profile

  • Photos of a trap or drain repair, with the joint and washer visible
  • List the sink types and faucet brands you service under the sink
  • Note the cabinet and subfloor repairs you do when a sink has leaked
  • Show a before and after of a rotted cabinet base repaired and sealed

Follow-up that helps the customer

  • Offer to check the supply lines and shutoff valves on the same visit when they are old
  • Recommend a cabinet check when the leak was slow and the floor was wet
  • Suggest a drain clean-out for the kitchen sink when grease has built up in the trap

Licenses and permits

Sink repair on the drain and supply lines is commonly done by licensed plumbers, and some simple washer or trap work is allowed without a license in some areas. Confirm the rules with your state or local licensing agency before taking the work.

Questions

What do I say when the customer wants the whole sink replaced for a trap leak?

Show the trap and the joint, and explain the repair. Only recommend the sink replacement if the bowl or mounting is the real problem, and show the reason.

How do I handle a sink that has rotted cabinet floor under it?

Stop and show the damage. Quote the cabinet and floor repair separately, and do not reset the sink over soft wood.

How do I test a repair under the sink?

Fill the sink, drain it, and run the faucet while you check each joint and the cabinet floor. A repair is not done until the joints are dry under load.

About this guide

This national guide is written and checked by infinibell. Rules and conditions differ by place, so local pros are credited on guides for the cities they serve, not on national ones.

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