stesso

Project

Take a small amount of plumber's putty and roll it into a snake-like rope about 1/2-inch thick. Press this rope firmly around the underside of the new sink flange (the metal drain piece). From the top of the sink, press the flange down into the drain opening so it is seated evenly. From underneath the sink, slide the fiber gasket, then the backup flange (a metal or plastic ring), and finally the mounting ring over the sink flange's neck. Secure these by threading on the snap ring; push it on until it pops into the groove on the flange. Tighten the three mounting screws on the mounting ring evenly with a screwdriver. This will squeeze the backup flange up, compressing the putty and creating a watertight seal. Scrape away any excess putty that squeezes out in the sink basin.

You're viewing a step from: How to Install a Garbage Disposal for the First Time

Beginner

30 minutes

2/4 Inventory

A comprehensive, step-by-step guide for a first-time installation of a garbage disposal. This process involves preparing the sink area, removing the existing sink drain, installing the new disposal mounting assembly, mounting the unit, and connecting all plumbing and electrical components.

Based on content fromThis Old House· 2.2M subscribers

Frequently Asked Questions

What are the essential safety steps to take before and during a first-time garbage disposal installation?

Always turn off the power to the sink area at the circuit breaker first to prevent electrical shock. Wear safety glasses to protect your eyes from debris, and use a bucket and rags to manage water spills. Ensure all electrical connections are secure and properly grounded before restoring power.

Beyond the disposal unit itself, what critical tools and materials are often overlooked but necessary for a smooth installation?

Don't forget plumber's putty for sealing the sink flange, a large bucket and plenty of rags (like HDX Microfiber Rags or WYPALL Towels) for catching residual water, and a good flashlight (like the Panther Vision FLATEYE) to illuminate the workspace. While not always included, you may need a specific InSinkErator 3 ft. Power Cord Installation Kit if your unit isn't pre-wired.

How much time should a beginner set aside for this project, and which part is typically the most challenging?

A first-time garbage disposal installation typically takes 2-4 hours, assuming no major plumbing issues. The most challenging parts are often securing the mounting assembly tightly to the sink to prevent leaks, and making proper, safe electrical connections if you're wiring it yourself rather than just plugging it in.

What are the most common mistakes first-time installers make, and how can I avoid them, especially regarding leaks?

Common mistakes include not applying enough plumber's putty around the sink flange, forgetting to remove the dishwasher knockout plug (if connecting a dishwasher), or not tightening the mounting bolts evenly. To avoid leaks, ensure all connections are hand-tightened and then carefully finished with pliers, and always double-check by running water through the sink for several minutes before buttoning everything up.