Silicone vs Rubber

In this article, you will learn about the main properties of different kinds of elastomers, and their usage in plumbing. These well-known materials – silicone and rubber – often get confused with one another because of their elastic behavior. After this close inspection, deciding whether ‘’Silicone vs Rubber’’ is the right sealant for your fittings will be easy.

Is Silicone a Rubber?


The breaking down of this distinction begins from the core elements of these materials – and the elements they share.

In short, the answer is no. The silicone acts as synthetic rubber, whereas the rubber is natural.

However, there is a synthetic rubber made and used just as frequently. Also, both silicone and natural rubbers are elastomers and polymers.

To make things less confusing, here is the explanation of these terms:

  • Polymers – a substance that consists of a group of natural or synthetic molecules
  • Elastomers – are polymers displaying elastic behaviors. They can be natural or synthetic
  • Synthetic – means man-made, something that can’t be found in nature

Synthetic materials can also be natural materials but synthesized. That’s the exact case with the silicone, too.

Silicone is a man-made product, extracted from natural sand, and passed through hydrocarbons. If we were to look closely into it, we would see that this polymer is made out of polysiloxane.

Polysiloxane – combined atoms of silicon, oxygen, carbon, and hydrogen.

What does all of this have to do with silicone usage in plumbing or HVAC?

The unique combination of atoms makes it a material with many beneficial properties that are hard to find in other elastomers. The benefits of silicone elastomers include:

  • Resistance to extremely high temperatures
  • UV-light resistance
  • Weather resistance
  • Antimicrobial
  • Non-toxic
  • Odorless

These characteristics of silicone make it a perfect sealant for many plumbing jobs. It’s used to fill out gaps and seams, seal plumbing fixtures or undersides of sink drains or other pop-up fittings.

Silicone also serves as a perfect plumber’s putty alternative, as it can stop mold from growing in areas exposed to moisture. In contrast to putty, it can be applied to many porous surfaces including wood, porcelain, marble, etc.

Silicone vs Rubber : Structure

How these materials are structured in turn affects their properties and performance in plumbing jobs.

Silicone is often considered a superior rubber, as its silicon-oxygen bonds perform well at very high temperatures. In those conditions, silicone also shows exceptional tensile and tear properties, and is resistant to fungus and some other chemicals.

Natural rubber, on the other hand, is extracted from the rubber tree and is mostly made out of carbon-carbon bonds. [1]

It’s a material praised for its elasticity and waterproof qualities. This is why we often see the rubber used for making medical devices, gloves, electronics, car ties, etc.

In plumbing, they act as a sealant or against corrosion damage, because of the waterproof qualities of the rubber.

Rubber is also less heat resistant than silicone, as it shows poor tensile and tear properties under high temperatures.

This is why silicone is a synthetic product, made specifically to perform well under demanding conditions.

Moreso, natural rubber still serves as an excellent waterproof, elastic product. Combined with its insulating and anti-static properties, it’s still a widely used and desirable material.

Is Silicone Latex Based?

Before we go on, let’s clarify the meaning of Latex, as it frequently shows up as a synonym to rubber and/or silicone, at times.

Latex is a milky white sap tapped from rubber trees and we get natural rubber from it. [2]

Since latex is harvested from a plant, it’s a natural element, but it can be also produced artificially through some of the chemical processes.

Latex is more commonly natural but can be synthetically produced too.

Often, latex is treated through many different processes to produce rubber, including heating, extrusion, vulcanization, etc. So, the natural rubber does contain latex, as it is made from it.

Silicone, on the other hand, is a completely man-made product and is not latex-based.

By now, you may wonder, why is this distinction important for my plumbing work?

It’s very important to note that latex can cause severe allergic reactions in some people. In contrast, silicone does not cause any allergic reactions and is more durable than latex.

Think about this next time you buy your gloves, caulking, or other plumbing equipment. Even though latex is cheaper and eco-friendly, silicone is safer to use and stronger for most of your plumbing jobs.

Silicone vs Rubber: Caulks and Adhesives


Silicone and rubber can serve as both caulks and adhesives.

However, first, note the difference between caulks and adhesives.

Caulk serves as a sealant for pipes and plumbing to create a barrier for water or gas. On the other hand, adhesives serve to bond different (or the same) materials together.

The Uses of Silicone Caulk :

  • Sealing the bathroom or kitchen fittings exposed to water and/or high temperatures
  • Adheres to metal, plastic, marble, ceramic, and glass
  • Can also be used for cables, electronic devices, and other appliances

Avoid using silicone caulk on wood or any other surface you plan to paint over, as it’s not paintable. Also, be careful when using it as cleaning it up is not easy.

The Uses of Silicone Adhesives:

  • To assembly windows
  • Bond glass, metals, ceramics, and plastic
  • Brickwork

Silicone adhesives are equally as resistant to high temperatures as silicone caulk. They require a drying time of up to 24 hours.

The Uses of Rubber Caulk:

  • Building work including wood, masonry, drywall
  • Stronger rubber caulks can be used to fill in gaps in metal, bricks, and concrete

Rubber caulk is not as long-lasting as silicone, but it’s possible to paint over it and easier to clean up.

The Uses of Rubber Adhesives:

  • For gluing almost any material including plastic, metal, wood, glass, ceramics, concrete, paper, and even rubber

Despite the variety of their use, avoid using rubber-based adhesives on surfaces exposed to pressure and water.

Silicone Rubber Gaskets


Besides caulks and adhesives, there is Silicone Rubber.

Silicone Rubbers are elastomers composed of silicone. They are specifically designed with properties useful on many occasions, such as in-home repair and hardware.

Now, when quality meets practicality, you get silicone rubber gaskets!

Silicone rubber gaskets are used to create a mechanical seal on a wide range of areas where extreme temperatures are present. As they contain silicone, they are highly resistant to both cold and hot temperatures and are also effective in stopping leaks.

Another great advantage they have is that they stay equally as elastic during those changes in temperatures. They are also resistant to most chemicals, UV-light, and waterproof.

All of these characteristics make silicone rubber gaskets a perfect fit for vent ducts, doors, windows, and HVAC in general. These gaskets can be used for thermal insulation because of their excellent high-temperature resistance.

Silicone rubber gaskets are super resistant to not only water, but also fire, ozone, aging, and pressure. They show great tensile and tear strength.

Best of all, silicone rubber gaskets have a really long life span. This is very useful information, as it can save you some costs for those expensive plumbing repairs.

Finally, there are now silicone rubber gaskets molded perfectly for your occasion. If you’re in need of bespoke gaskets, make sure you order a molded gasket specifically manufactured for your needs.

Bottom Line

Choosing whether Silicone vs Rubber is the right material greatly depends on the situation you plan on using them.

With outdoor home repairs, one has to use the material which is resistant to temperature and weather changes. Silicone performs better in demanding conditions, as it is a synthetic product made for that purpose.

On the other hand, natural rubber still serves as an amazing elastic material, suitable for stopping water leaks and thermoregulation.