Keeping the water out and ensuring everything is sealed up tight is important for taps, pipes, and more. And that’s where plumber’s putty and silicone are invaluable—but which one should you use?
Silicone is better than plumber’s putty for repairing cracks or for sticking things back together. This is because silicone is an adhesive. However, plumber’s putty is preferable if you need to mold around a small area and want a flexible finish.
It’s clear that both plumber’s putty and silicone have their uses in bathrooms, kitchens, and other areas around the home. I’m going to look in more detail about when to use each one.
Plumber’s Putty Vs. Silicone
Plumber’s putty and silicone are often lumped together, and many people believe them to be interchangeable.
This is not the case.
The qualities of plumber’s putty and silicone are very distinct and separate, which makes them suitable for different types of jobs.
Much of the confusion arises because both can produce a water-resistant finish, and both are commonly used in kitchens and bathrooms. However, that’s where the similarity ends.
To understand the best ways to use plumber’s putty and silicone, let’s have a look at what each of them is made from.
What Is Plumber’s Putty?
Plumber’s putty is a soft and malleable compound that can be squished into shape and molded around pipes as needed.
It’s made primarily from clay and linseed oil, together with other materials such as limestone, fish oil, and talc.
Plumber’s putty is a staple of any plumber’s toolkit and can be used for a variety of jobs that require a water-resistant seal.
What Is Silicone?
Unlike plumber’s putty, silicone is an adhesive which means that it hardens after use.
Silicone is a synthetic polymer which is made from silica, a type of sand that is commonly found in quartz.
Silicone isn’t as toxic as other types of adhesives, which makes it a popular choice for any kind of repair that requires bonding and a water-resistant finish.
Understanding the Key Differences Between Plumber’s Putty and Silicone
Although plumber’s putty and silicone can be used for similar purposes, they are quite different substances.
It’s important to understand the relative pros and cons of each to choose the best option for the job.
Below is an overview of them both:
Plumber’s Putty Pros and Cons (Table)
| Pros | Cons |
|---|---|
| Soft and pliable | Doesn’t always stick very well and is susceptible to gravity |
| Easy to mold into shape | It’s not an adhesive, so it won’t stick things together |
| Can be pulled off and re-positioned as many times as you need | Not designed for use over large areas |
| Old plumber’s putty can be easily removed | Can stain |
| Can last for decades without failing | |
| No need to wait for it to dry before use |
Silicone Pros and Cons (Table)
| Pros | Cons |
|---|---|
| Dries to a hard finish, so it won’t easily crack or leak | Difficult to remove—a tool will be required to retrieve the small, hardened pieces |
| Can be used over very large areas | Must be placed precisely, as it can’t be repositioned |
| Can be used as an adhesive as well as a sealant | Not very easy to shape or mold due to its hardness |
| Works well on ceramic and plastics | Lasts 10-20 years—much less than plumbers putty |
| Must properly dry out and become hard before use |
What To Consider When Choosing Plumber’s Putty or Silicone
Looking through the above table, it’s clear that there are some occasions where the choice between plumber’s putty and silicone will be obvious.
To help narrow the decision down further, it might be helpful to consider the following factors:
1. Drying Time
Plumber’s putty will always remain soft; this is one of the qualities which makes it so popular.
This means that it doesn’t need to dry on application, and you don’t need to wait for it to harden.
In contrast, silicone will take a minimum of 24 hours to set and may need as long as 72 hours, depending on the humidity and temperature.
You’ll need to be able to leave the silicone to set before use, and this needs to be considered when carrying out the repair.
2. Materials
The materials you will be using may be the deciding factor.
This is because plumber’s putty isn’t as versatile and only has limited applications.
Silicone can be used on a huge range of materials that plumber’s putty doesn’t like to stick to, including metal, PVC, glass, porcelain, tiles, marble, granite, and natural stone.
3. Toxicity
Plumber’s putty is non-toxic and biodegradable, meaning you can use it in smaller spaces, such as bathrooms, without a problem.
Silicone needs special care to be handled correctly, and it can release VOCs (Volatile Organic Compounds) into the air.
If you breathe these in, they can be harmful to your health, so good ventilation is vital when working with silicone.
4. UV Exposure
Because plumber’s putty is intended to stay soft and pliable, it doesn’t like UV light.
When exposed to UV light, the putty becomes brittle and hardens, gradually breaking down and crumbling.
Silicone is not affected by UV light and can be used in outdoor applications or around doors and windows.
5. Water-Resistance
Plumber’s putty can’t be used to create a watertight seal in an exposed area.
It is water-resistant, but if you need an exposed seal that’s strong and watertight, putty won’t do the job.
It’s better used around pipes to seal joints, under sinks, or around faucets out of sight.
The harder finish of silicone means that it won’t absorb any water, and it’s far more water-resistant.
It’s better to use in exposed areas but you’ll need to make sure you have access to be able to scrape off the silicone in the future, should you need to remove the part.
6. Application
Plumber’s putty is soft and easy to shape with your hands, which is ideal if you want to seal around a pipe or a joint.
Providing the material is compatible with plumbers’ putty, it’s easy to apply, and you don’t need to worry about waiting for it to dry.
Due to the length of time silicone takes to dry, you’ll need to consider gravity when applying it.
It’s also not possible to mold or shape silicone, and once it’s been applied, there’s no second chance to get it right.
Final Thoughts
Both plumber’s putty and silicone are suitable for use in repairs where the finish needs to be water-resistant and leakproof.
If you are repairing an area that is likely to need to be replaced in the future, such as a drain cover, the soft and pliable nature of plumber’s putty makes it the best solution.
However, for sticking areas together or for large repairs, the hard, adhesive finish of silicone would be better.
Both silicone and plumber’s putty have their uses, and hopefully, now you’ve got a better understanding of how to select the right one.
Cheers, tools owners!
