Skill Level Legend:
Beginner: Simple tools, no flame or cutting involved. Great for first-timers.
Intermediate: Requires basic plumbing knowledge and comfort with hand tools or heat.
Advanced: Complex techniques, potential for damage if done incorrectly. Best left to professionals.
Skill Level: Beginner Estimated time: 20–30 minutes
When installing or replacing a sink drain, one of the simplest yet most important steps is creating a watertight seal between the drain flange and the sink. That’s where plumber’s putty comes in. This soft, moldable sealing compound has been a go-to for plumbers for decades because it’s easy to work with and perfect for sealing sink drains, strainers and other fixtures.
In this guide, we’ll walk you through how to apply plumber’s putty to a sink drain so you can achieve a leak-free, professional looking results without calling in the pros (unless you want to, in which case, we’re always happy to help).
What You’ll Need
Before you get started, gather your tools and materials:
📌Plumber’s putty (make sure it’s safe for your sink’s material)
📌Sink drain assembly (drain body and flange)
📌Adjustable wrench or channel-lock pliers
📌Utility knife or plastic scraper (for cleanup)
📌Clean rag or paper towels
Step 1: Clean the Sink Surface
A good seal starts with a clean surface. Remove any old putty, sealant or debris from around the drain opening. Wipe it down with a damp cloth and dry thoroughly. Even small bits of old material can prevent the putty from sealing properly.
Pro Tip: If the old putty is stubborn, gently scrape it away with a plastic scraper to avoid scratching the sink.
Step 2: Prepare the Plumber’s Putty
Plumber’s putty comes in a tub and is soft and pliable, but if it’s cold or a little stiff, knead it in your hands for a minute or two to warm it up. Roll the putty between your palms into a rope about 1/4 inch thick long enough to wrap completely around the underside of the drain flange.
Note: Some modern sinks especially stone or composite can stain from traditional plumber’s putty. In those cases, choose a non-staining version or use a silicone sealant instead.
Step 3: Apply the Putty to the Drain Flange
Take your rope of putty and place it around the underside edge of the drain flange. Press it gently so it sticks in place but don’t flatten it completely yet, you want it to mold into the gap when you tighten the drain.
Step 4: Insert the Drain Body
Carefully position the drain body through the sink’s drain opening, with the flange (and putty) on top. From underneath the sink, attach the gasket, washer and locknut (these come with your drain assembly).
Step 5: Tighten the Assembly
Using your adjustable wrench or pliers, tighten the locknut underneath the sink while holding the drain body steady from above. As you tighten, the plumber’s putty will compress and form a watertight seal between the sink and the drain flange.
Pro Tip: Tighten gradually and evenly. Over-tightening can crack porcelain sinks or warp metal parts.
Step 6: Remove Excess Putty
Once the drain is fully secured, you’ll see excess putty squeezed out around the flange. Simply run a utility knife blade or your finger around the edge to remove it, and wipe the area with a clean rag.
Step 7: Test for Leaks
Before reconnecting the P-trap or drainpipe, place a bucket under the drain and fill the sink with water. Let it sit for a minute, then release the water and check underneath for drips. If it’s dry, congratulations, you’ve got a watertight seal!
Why Use Plumber’s Putty? Plumber’s putty is ideal for situations where you need a flexible, removable seal that’s exposed to water but not pressurized flow. Unlike silicone caulk, putty remains soft over time, making it easy to remove a fixture later without damaging the sink.
Common Mistakes to Avoid
- Using on the wrong surfaces: Avoid standard putty on granite, marble or other porous stone. Use non-staining putty instead.
- Skipping the cleanup: Leaving excess putty around the flange can collect grime and look messy.
- Not kneading the putty: Cold, stiff putty won’t mold properly and may cause leaks.
Maintenance and Longevity – A properly applied plumber’s putty seal can last for many years. You typically won’t need to replace it unless you remove the drain for repairs or upgrades. If you notice leaks in the future, it’s often as simple as removing the old putty, cleaning the area and reapplying fresh putty.
Applying plumber’s putty to a sink drain is one of those basic plumbing skills every homeowner should know. It’s inexpensive, quick, and can save you from frustrating leaks and water damage down the line.
Whether you’re tackling a DIY drain installation or just want to understand the process before calling us, knowing how plumber’s putty works gives you confidence in your plumbing projects.
And if you run into trouble or just prefer a leak-proof guarantee The Great Plumbing Co. is here to help. Our experienced team can handle everything from sink installs to faucet replacements, drain repairs and more all with friendly service and professional results.
The Great Plumbing Co.
For nearly three decades, The Great Plumbing Co. has been providing exceptional plumbing services for homeowners as well as business owners throughout Toronto and the GTA. Whether you’re dealing with a leaky hose bib, a clogged drain, or a toilet repair and service you can trust The Great Plumbing Co. to deliver timely solutions tailored to your specific requirements.
Contact us or book online to schedule your residential plumbing appointment.
The Great Plumbing Co.
For nearly three decades, The Great Plumbing Co. has been providing exceptional plumbing services for homeowners as well as business owners throughout Toronto and the GTA. Whether you’re dealing with a leaky hose bib, a clogged drain, or a toilet repair and service you can trust The Great Plumbing Co. to deliver timely solutions tailored to your specific requirements.
Contact us or book online to schedule your residential plumbing appointment.
