Plumbers putty vs silicone: Which sealant is best for your plumbing?

Sealants are materials used to fill gaps, joints, or seams between plumbing fixtures to prevent water leaks. They come in different forms, such as pastes, gels, or liquids. Two of the most common types used in plumbing are plumber’s putty and silicone sealant.

So, how do you decide between plumbers putty vs silicone for your plumbing project?

In this guide, we’ll explain their key features, benefits, and drawbacks, helping you choose the best plumber’s sealant for your specific needs.

What is plumber’s putty?

Plumber’s putty is a soft, malleable sealing compound with a flexible, clay-like texture that does not harden over time. 

And what is plumber’s putty used for exactly? It’s applied around sink drains, faucet bases, shower drain fittings, bathtub drains, and overflow plates. Plumber’s putty is also useful for filling small gaps or imperfections between sinks and countertops to prevent water from leaking into unwanted areas.

Key features of plumber’s putty

A key feature is that you can create strong, watertight seals that stay soft and flexible even after they're applied. This makes them easy to remove and reposition if you need to make adjustments later. You can also mold them into any size or shape you need.

Another essential feature is that plumber’s putty is very simple to use. You don’t need any tools, making it a favorite for professionals and DIYers. Just roll it into a rope and press it where required. If you use too much, wipe away the extra. There's no drying time, no mixing, and no sticky mess.

Advantages and drawbacks of plumber’s putty

Plumber’s putty is a popular choice for many plumbing tasks because of its versatility and ease of use. However, it’s not the right choice for every job. Let’s look at its advantages and some drawbacks:

• Ease of use and malleability: Plumber’s putty is easy to handle. You don’t need tools or special skills. Just roll it into a rope and press it where needed. This makes it great for filling gaps, curves, and corners where a perfect fit is needed. 
• Reliable watertight seal: Plumber’s putty creates a strong, watertight seal perfect for areas that don’t experience high pressure, like the base of a sink drain or around a faucet. It performs well in these conditions for years without cracking, shrinking, or drying out. However, it’s unsuitable for pressurized systems, such as threaded pipe joints or water supply lines, where it can fail or wash away over time.
• Used across various surfaces: Plumber’s putty works well on various non-porous materials, including metal, stainless steel, and some types of granite, and it won’t stain or discolor their surfaces. However, it’s unsuitable for plastics, marble, or unsealed granite as they will absorb the oils in the putty, leading to staining or surface damage.
• Cost-effective: Plumber’s putty is affordable. A small tub typically costs just a few dollars and will last through multiple projects. However, if the container isn’t sealed tightly after use, the putty can dry out and become crumbly or unusable.
• Limited resistance to harsh conditions: Exposing plumbers’ putty to chemicals, direct sunlight, or extreme heat and cold will shorten its lifespan, weaken the seal, and cause cracking.
• Clean application: Overall, it’s a clean product to work with and easy to wipe away excess, but using too much can cause the putty to squish out around the edges of the fixture.

How long does plumber’s putty take to dry? You don’t actually need to wait for plumber’s putty to dry or cure. Once applied, the fixture can be used immediately.

What is silicone sealant?

Silicone is a flexible, rubber-like substance made from silicone polymers that creates strong, waterproof seals in plumbing and construction. It’s commonly applied around sinks, bathtubs, toilets, and pipes to prevent water leaks and protect joints from damage.

Silicone sealant is often grouped with traditional caulk, but there are notable differences between the two. For instance, traditional caulk is usually made from acrylic or latex and tends to dry hard and brittle over time, leading to cracks and failure in areas with frequent movement or moisture. Silicone sealant, by contrast, stays elastic and durable, making it more suitable for wet or high-stress environments. Additionally, silicone offers better adhesion to a broader range of surfaces and is more resistant to mold and mildew.

Key features of silicone

Silicone is known for its strong adhesive and waterproof properties. Once it cures, it forms a rubber-like seal that tightly bonds to various surfaces. Another standout feature of silicone is its durability. It can withstand exposure to moisture, high temperatures, high pressure, and even direct sunlight without breaking down or losing its seal. This makes it perfect for both indoor and outdoor use.

Advantages and drawbacks of silicone

Silicone sealant offers dependability and versatility. However, depending on the project, there are also some trade-offs to be aware of.

• Long-lasting and weather-resistant: Once fully cured, silicone creates a rubbery, permanent seal that holds up for years and won’t crack, dry out, or crumble when exposed to constant moisture, UV rays, or extreme temperatures. This makes it an ideal choice for indoor and outdoor applications where reliability is needed.
• Versatile on many surfaces: Silicone sticks well to various materials, including glass, ceramic, porcelain, metal, plastic, and wood. However, it doesn’t bond well to oily or dusty surfaces, and certain types of silicone may not be paintable or suitable for porous materials like raw stone or unsealed concrete.
• Strong seal for demanding environments: Plumber silicone performs well in high-moisture and high-pressure areas like shower stalls, bathtubs, and joints that expand or contract due to heat or movement. It also resists mold and mildew in humid areas.
• Curing time and difficulty in removal when cured: Silicone sealant requires 24 to 72 hours before it becomes waterproof and fully effective. This can slow down a project or a fixture's usage. Additionally, silicone bonds tightly once it dries and is difficult to remove without damaging the surface. Hence, it’s not always the best for DIY projects.
• Slightly more expensive: Silicone sealant costs more than putty and usually requires a caulking gun, which adds to the cost if you don’t already have one.

Comparing plumbers putty vs silicone

Plumbers putty or silicone are common sealants used in plumbing, but they serve different purposes and perform differently depending on the situation. Understanding their differences can help you choose the right one for your project.

Adhesion

Silicone vs plumbers putty? Silicone has strong adhesive properties. It sticks tightly to surfaces and forms a long-lasting bond that’s hard to remove once cured. On the other hand, plumber’s putty doesn’t bond to surfaces. It forms a watertight barrier by being pressed into place.

Durability

Once silicone cures, it’s heat-resistant and UV-resistant and won’t crack or crumble over time. It can hold up in high-moisture, high-pressure, and high-temperature environments for years. Plumber’s putty is more short-term. It will lose its seal if exposed to heavy water flow, pressure, or fluctuating temperatures.

Waterproofing

Both silicone and plumber’s putty are waterproof. Silicone seals out air and moisture, making it great for wet and draft-prone areas. Plumber’s putty works more by blocking water entry rather than bonding surfaces together.

Ease of use

Plumber’s putty is easy to work with, especially for beginners. There’s no curing time; you can install your fixture and use it right away. Silicone takes more time and tools. It’s applied with a caulking gun, needs a clean surface to bond, and takes 24 to 72 hours to cure before being exposed to water. Plus, if you make a mistake, it’s tricky to remove dried silicone.

Best use cases

Plumber’s putty is perfect for temporary seals in indoor plumbing, like sink drains, faucets, or other fixtures where you may need to remove or adjust the part later. Silicone is better for permanent installations or situations involving high water pressure, movement, or outdoor exposure. It’s your go-to for sealing around tubs, showers, windows, and toilets.

When not to use plumber’s putty

Using plumber’s putty in the wrong setting can lead to leaks, damage, or a failed seal. Here are the most common cases when it should not be used.

• Plumber’s putty can break down certain types of plastic, especially ABS, causing it to warp, crack, or weaken.
• Oil-based putties can stain or discolor porous stone surfaces, leaving behind permanent marks.
• Plumber’s putty doesn’t bond to surfaces or harden, so it can’t withstand movement, vibration, and high pressure.
• Putty is not for exterior purposes, as it cannot withstand UV rays, extreme temperatures, rain, or snow.

Silicone sealant is a much better plumber’s putty alternative in these high-pressure situations. Once cured, it resists pressure, temperature changes, moisture, and movement. This makes it ideal for sealing water supply lines, pipe joints, toilet connections, and outdoor plumbing where durability and a watertight seal are critical.

Choosing the right sealant for your plumbing needs

The right sealant depends on the project and the conditions attached. A rule of thumb is to use plumber’s putty for indoor, low-pressure applications like sealing sink drains and faucets. Conversely, plumbing silicone is best for high-pressure, outdoor, or constantly wet areas, such as around toilets, water supply lines, or outdoor pipes.