When you’re tackling a plumbing project—whether it’s installing a new faucet, sealing a drain, or fixing a leaky sink—choosing the right sealant is key. But many homeowners get stuck on one common question: should I use plumber’s putty or silicone?
These two materials might seem similar, but they serve different purposes. Using the wrong one can lead to leaks, costly damage, or wasted effort. In this guide, you’ll get a clear, side-by-side comparison of plumber’s putty vs. silicone caulk—so you know exactly when to use each one.
What Is Plumber’s Putty?
Plumber’s putty is a soft, moldable substance used for creating watertight seals around plumbing fixtures. It’s often used by pros for tasks like setting sink drains or faucet bases. It never hardens completely, which makes it easy to reposition or remove later.
The consistency is similar to clay or dough, and you apply it by rolling it into a rope and pressing it around the edge of a fixture. Once installed, the putty compresses and seals out water without needing any dry time.
Typical Ingredients:
- Limestone
- Mineral oil or other non-drying oils
- Clay compounds
Common Uses for Plumber’s Putty:
- Sink drain assemblies
- Faucet bases
- Strainer baskets
- Non-pressurized fittings
Plumber’s putty is known for being easy to work with. If you make a mistake or want to move a part later, you can simply remove the putty and reapply.
What Is Silicone Caulk?
Silicone is a rubber-like adhesive that creates a permanent, waterproof seal. Unlike putty, it cures over time—usually within 24 to 48 hours—and becomes flexible and durable once dry. It’s ideal for sealing joints, corners, or gaps where water could enter or leak out.
Silicone is a go-to for high-moisture environments like bathrooms and kitchens. It’s especially useful where surfaces expand and contract due to heat, like around bathtubs or tiles.
Common Types of Silicone Sealants:
- 100% silicone (most waterproof)
- Siliconized acrylic latex (paintable, but less waterproof)
- Mold- and mildew-resistant formulas (ideal for wet zones)
Common Uses for Silicone:
- Bathtubs and shower enclosures
- Toilet bases
- Backsplashes and countertops
- Outdoor fixtures exposed to the elements
Unlike plumber’s putty, silicone sticks to nearly everything and is designed to stay in place long-term.
Plumber’s Putty vs. Silicone: What’s the Real Difference?
Here’s a detailed look at how they compare across key categories:
| Feature | Plumber’s Putty | Silicone Caulk |
|---|---|---|
| Adhesion | Non-adhesive; creates a seal through compression | Strong adhesive bond to most materials |
| Dry/Cure Time | Immediate seal; no curing required | 24–72 hours to fully cure |
| Water Resistance | Water-tight in low-pressure, indoor settings | Fully waterproof, even under pressure |
| Removability | Easy to remove and replace | Difficult to remove after curing |
| Flexibility | Remains pliable but not stretchy | Flexible and expands/contracts with surface |
| Appearance | Hidden under fixtures; not meant to be visible | Can be visible; available in various colors |
| Suitability for Outdoors | Not recommended (can dry out, crack) | Excellent for outdoor use |
When Should You Use Plumber’s Putty?
Best use: under sink drains or faucet bases where the putty stays compressed between two surfaces.
Choose plumber’s putty if:
- You’re installing a drain basket in a kitchen or bathroom sink
- You need a seal that you might want to undo or redo later
- You’re working with non-porous surfaces like stainless steel or porcelain
Avoid it if: you’re sealing plastic, granite, or any porous material—it could stain. Also, don’t use it on pressurized joints or threaded pipes. It’s not meant to hold pressure like pipe thread sealant or Teflon tape.
When Should You Use Silicone?
Best use: for visible or long-lasting seals in high-moisture or outdoor environments.
Choose silicone if:
- You’re sealing around bathtubs, shower stalls, or tile edges
- You need a waterproof seal that won’t move or shift
- You’re working outdoors or in humid areas like basements
Avoid it if: you might need to remove or reposition the part later. Silicone is a pain to clean up once cured and can leave behind residue.
Tips from the Pros
“Plumber’s putty is great when you need something forgiving—like under a sink drain where you might have to adjust the fit. But for tubs and tile, silicone wins every time.” — Licensed Plumber, 15+ Years
“If it’s visible and needs to stay put, I always go with silicone. Putty is just too soft for anything exposed.” — Kitchen Remodel Contractor
How to Apply Each One Correctly
Using Plumber’s Putty:
- Roll it into a snake about ¼-inch thick.
- Apply it evenly around the edge of the part being sealed (like a drain flange).
- Press the part into place and tighten it.
- Wipe away excess putty that squeezes out.
Using Silicone Caulk:
- Clean and dry the surface thoroughly.
- Cut the nozzle at a 45° angle and load the tube into a caulk gun.
- Apply a steady bead along the joint or seam.
- Smooth it with a wet finger or caulk tool.
- Let it cure for at least 24 hours before exposure to water.
Still Not Sure Which to Use?
Here’s a quick cheat sheet:
- Sink drain basket? → Plumber’s putty
- Bathtub edge? → Silicone
- Outdoor pipe joint? → Silicone
- Faucet base installation? → Plumber’s putty
- Toilet base? → Silicone (for permanent seal)
Conclusion
Choosing between plumber’s putty and silicone comes down to the job at hand. Each one serves a specific purpose:
- Use plumber’s putty for easy-to-remove, non-pressurized seals under sinks or faucets.
- Use silicone for long-lasting, waterproof seals around tubs, showers, and tiles.
Understanding the difference helps you avoid mess, damage, and wasted time. And for any plumbing upgrade, don’t forget one last thing—your septic system.
Protect your pipes and plumbing with SEPTIFIX – The #1 Septic Tank Treatment. It keeps your system clean, odor-free, and clog-resistant—so your next seal job doesn’t turn into a septic emergency.
Ready to seal smarter? Choose the right product, apply it well, and keep everything flowing properly with a little help from SEPTIFIX.