• In this video, Ask This Old House plumbing and heating expert Richard Trethewey helps a homeowner reattach an undermount kitchen sink to a granite countertop.

    1. Turn off the water supply to the sink.
    2. Disconnect plumbing connections using a wrench and unscrew by hand.
    3. Disconnect any remaining sink clips, using a screwdriver.
    4. Remove sink from granite and set aside.
    5. Scrape off leftover caulking on the sink and the underside of the granite countertop using a putty knife.
    6. Insert undercounter-mount sink clips into the existing holes in the granite.
    7. Loosely screw the machine screws into the brass threaded insets using a screwdriver.
    8. Put a bead of silicone caulking around the rim of the sink using the caulking gun.
    9. Place the sink back into the hole in the granite and pull it up into place using a string wrapped through the drain.
    10. Have another person underneath the countertop to tighten the machine screws into the granite and place the clips under the rim of the sink.
    11. Place wood braces tight under the sink for support.
    12. Run a finger along the rim of the sink to smooth out caulking and add more as needed.
    13. Reconnect pipes and turn the water back on.
    14. Wait 24 hours before removing the wood braces or using the sink.
    • Difficulty: Moderate
Ask TOH users about Kitchen Sinks

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      Video Directory

      Selected Topic/Section

      Tools List

      • multi-bit screwdriver
      • adjustable wrench
      • caulk gun
        Caulking gun
      • putty knife
        Putty knife

      Shopping List

      Undercounter-mount sink clips (comes with wing nuts and machine screws)

      1-inch fender washers

      Silicone caulking

      Length of string

      Wood braces