Sink installation: a guide for pros

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

Offering sink installation

Sink installation is a fit-and-seal job, and many callbacks come from a sink that did not fit the cutout or a seal that was set wrong. Confirm the fit before the old sink comes out.

What customers ask

  • Will the new sink fit my counter?
  • Do I need a new drain?
  • Why is the sink leaking at the rim?
  • Can you put in an undermount sink with the granite I already have?
  • Who fixes the counter if it cracks when the sink is cut?

How to win the job

  • On the first call, get the sink model, the counter material, the cutout size, and photos of the cabinet below, and ask whether the drain and supply are in place.
  • Bring undermount clips, rim seal, plumber's putty, a new drain assembly, a trap kit and supply lines to the first visit.
  • Confirm the cutout and the support before you order the sink, and show the customer the fit on a template if one is needed.
  • Quote the sink, the drain assembly, the trap, the supply lines and the sealant as separate lines.
  • Set the sink with the right seal for its type, and let the seal cure before you load the sink with weight.
  • Test the drain and the supply under water and check the rim seal before you leave.

What to put on your profile

  • Photos of a finished undermount or drop-in install, showing the rim or the clip detail
  • List the sink types you install, and the counter materials you work with
  • Note the drain assembly and trap replacements you do with each sink
  • Show a before and after of a sink that was leaking at the rim, fixed and tested

Follow-up that helps the customer

  • Offer to check the seal and the drain after the first week of use
  • Suggest a new supply line check for the faucet, when it is installed with the sink
  • Recommend a cabinet check under the sink, if the old sink leaked into it

Licenses and permits

Sink installation's plumbing portion is commonly done by licensed plumbers, and counter cutting may be handled by a different licensed or trained trade. Confirm the requirements with your state or local licensing agency before you take the work.

Questions

What do I say when the new sink does not fit the cutout?

Stop before cutting. Show the measurement and the options, which are a different sink, a counter change, or a cutout by the counter trade. Put the choice in writing.

How do I handle a customer who wants an undermount sink with a silicone-only seal?

Explain that undermount sinks need mounting clips and a proper seal. Show the clip detail and quote the clips as their own line.

What should I check in the cabinet during a sink install?

Look for rot, water stains, and a soft base. Show the customer any damage and quote the repair before setting the sink on it.

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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