Install New Mounting Assembly — Install Faucet and Strainer on the Sink
Part of project
How to Install an Undermount Kitchen Sink · Step 3 of 10
In this video
Take a generous amount of plumber's putty and roll it into a rope about a half-inch thick. Wrap this putty rope around the underside of the new sink flange. Press the flange firmly into the sink drain opening. From under the sink, slide the fiber gasket on, followed by the backup flange and the mounting ring. Hold these in place while you install the snap ring into the groove on the sink flange to hold the assembly together. Finally, use a screwdriver to tighten the three mounting screws evenly and firmly, which will pull the assembly tight against the sink and create a watertight seal.
Goal: Install New Sink Flange and Mounting Hardware
- Tighten the three screws in an alternating pattern to ensure even pressure and a good seal.
Used in this video
- Screwdriver (Tool Type: Hand tools, Screwdriver Type: Phillips) — Tightening the mounting screws.
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FAQs
Is installing an undermount kitchen sink truly an intermediate DIY project for a novice, given the 8-hour estimate?
While listed as 'intermediate' with an 8-hour estimate, the project involves critical plumbing connections, working in tight spaces, and precise sealant application, which can be challenging for beginners. If you're not confident with plumbing or power tools like a drill, consider hiring a professional for specific steps or the entire installation to avoid potential issues like leaks.
What are the most crucial specialized tools I'll need for this undermount sink installation, beyond basic household items?
Key specialized tools include adjustable and tongue and groove pliers (like the Channellock 430) for securing plumbing connections, and a reliable drill for installing the mounting clip anchors. A putty knife is essential for working with plumber's putty, and a good flashlight (like the NITECORE P20iX) will be invaluable for inspecting connections in dimly lit cabinet spaces.
What are the most common reasons for leaks after an undermount sink installation, and how can I prevent them?
Leaks typically occur due to insufficient sealant around the sink's rim, improperly tightened drain or water supply connections, or issues with the garbage disposal seal. Ensure a continuous, even bead of sealant when mounting the sink, hand-tighten plumbing connections first then give a quarter to half-turn with a wrench, and double-check all gaskets during assembly.
The project mentions Oatey Plumber's Putty; can I use 100% silicone sealant instead for mounting the sink to the countertop?
Yes, 100% silicone sealant is often preferred for undermount sinks, especially with stone countertops, as it creates a stronger, more permanent, and flexible waterproof bond than plumber's putty. While plumber's putty is excellent for sealing drains and strainers like the KRAUS Kitchen Sink Strainer, silicone offers enhanced long-term durability for the sink-to-countertop seal.
Install New Mounting Assembly — Install Faucet and Strainer on the Sink
Part of project
How to Install an Undermount Kitchen Sink · Step 3 of 10
In this video
Take a generous amount of plumber's putty and roll it into a rope about a half-inch thick. Wrap this putty rope around the underside of the new sink flange. Press the flange firmly into the sink drain opening. From under the sink, slide the fiber gasket on, followed by the backup flange and the mounting ring. Hold these in place while you install the snap ring into the groove on the sink flange to hold the assembly together. Finally, use a screwdriver to tighten the three mounting screws evenly and firmly, which will pull the assembly tight against the sink and create a watertight seal.
Goal: Install New Sink Flange and Mounting Hardware
- Tighten the three screws in an alternating pattern to ensure even pressure and a good seal.
Used in this video
- Screwdriver (Tool Type: Hand tools, Screwdriver Type: Phillips) — Tightening the mounting screws.
Frequently Asked Questions
Is installing an undermount kitchen sink truly an intermediate DIY project for a novice, given the 8-hour estimate?
While listed as 'intermediate' with an 8-hour estimate, the project involves critical plumbing connections, working in tight spaces, and precise sealant application, which can be challenging for beginners. If you're not confident with plumbing or power tools like a drill, consider hiring a professional for specific steps or the entire installation to avoid potential issues like leaks.
What are the most crucial specialized tools I'll need for this undermount sink installation, beyond basic household items?
Key specialized tools include adjustable and tongue and groove pliers (like the Channellock 430) for securing plumbing connections, and a reliable drill for installing the mounting clip anchors. A putty knife is essential for working with plumber's putty, and a good flashlight (like the NITECORE P20iX) will be invaluable for inspecting connections in dimly lit cabinet spaces.
What are the most common reasons for leaks after an undermount sink installation, and how can I prevent them?
Leaks typically occur due to insufficient sealant around the sink's rim, improperly tightened drain or water supply connections, or issues with the garbage disposal seal. Ensure a continuous, even bead of sealant when mounting the sink, hand-tighten plumbing connections first then give a quarter to half-turn with a wrench, and double-check all gaskets during assembly.
The project mentions Oatey Plumber's Putty; can I use 100% silicone sealant instead for mounting the sink to the countertop?
Yes, 100% silicone sealant is often preferred for undermount sinks, especially with stone countertops, as it creates a stronger, more permanent, and flexible waterproof bond than plumber's putty. While plumber's putty is excellent for sealing drains and strainers like the KRAUS Kitchen Sink Strainer, silicone offers enhanced long-term durability for the sink-to-countertop seal.