In many home improvement projects, there are gaps. For example, there are gaps between the window frame and the window sill. There are gaps between the bathtub and the wall. There are gaps between the sink and the wall. For kitchen and bath projects, silicone sealant is the ideal product. It’s waterproof and temperature resistant. In this article, we’ll answer some frequently asked questions or FAQs about silicone sealant.

What Is Silicone Sealant?

Silicone sealant is a liquid semi-viscous material that can be applied to gaps in various home improvement contexts. Its purpose is to prevent water or air from entering or escaping various cracks or gaps in your home. It’s usually applied from a caulking gun and takes about 24 hours to completely dry. Many people confuse silicone sealant with polyurethane caulk, but they are not the same thing.

What’s the Difference Between Polyurethane Caulk and Silicone Sealant?

Caulk and silicone sealant both serve the same purpose: to fill in gaps. This is typically done in a building and prevents air or water from entering or escaping through said gaps. Polyurethane caulk is more rigid than silicone sealant and doesn’t work as well on gaps that are more prone to expansion and contraction. Caulk also doesn’t handle water and moisture quite as well as silicone sealant. However, it does dry quicker than silicone sealant. You can also paint over caulk, while you’ll need to pre-paint any surface that you use silicone sealant on.

Silicone sealant is excellent for surfaces that are prone to high levels of moisture. Since they can expand and contract, sinks in the kitchen and bath can be sealed safely with silicone sealant. It can also be applied to tiles if their grout has worn away over time. One of the main benefits of silicone sealant is its flexibility. It is more resilient than polyurethane caulk. This pliability is what makes silicone sealant the quintessential product for expanding and contracting household gaps.

Silicone itself is non-toxic. It's used in the creation of dishes and even medical implants. Many silicone sealants contain chemical additives to make the material easier to apply. It is typically these additives that prevent silicone sealant from being completely non-toxic.

Despite this fact, silicone sealants are better for the environment than most other caulking compounds. According to BuildingClean.org, “Silicone sealants are used eight out of ten times in the construction market, in part because their low VOCs [volatile organic compounds] enable builders to earn green building credits.”

One way to avoid some of the toxicity of silicone sealant compounds is to use silicone sealant without additives. You can purchase silicone sealants that are 100% silicone, and these are the least toxic silicone sealants. 

With all that being said, you should still take safety precautions when working with silicone sealant. This includes using safety glasses and gloves while working with the material. If possible, you should crack a window as the fumes from the silicone sealant can build up over time. Refrain from touching your eyes when using silicone sealant and make sure to wash your hands when you’re done using it.

How Do I Apply Silicone Sealants?

The easiest way to apply silicone sealant is by using a caulking gun. To begin, you’ll need to fit the tube of silicone sealant into the caulking gun. To do that, you’ll first need to pull back the loading pin. Then you can insert the base of the silicone tube into the back end of the gun. From there, you can push the loading pin in to lock the tube of caulk into the gun.

Next, you’ll want to clean the area where you’re going to apply the silicone sealant. You can do this by using a sponge with soap and water. Ensuring that the area is clean before using the silicone sealant will give you a better seal. Make sure that you dry the area completely with a towel before applying the silicone sealant.

Next, you’ll want to cut the end of the silicone sealant tube with a utility knife. Cut a small hole at a 45-degree angle so that you can precisely control the amount of silicone sealant that exits the tube.

Before applying the silicone sealant, you can test it on a piece of scrap material. If you’re satisfied with the flow, you can then apply the sealant to the gap you’re working on. Use the trigger and apply the silicone sealant as slowly and evenly as you can. Keep a bucket of water nearby. You can wet your finger and smooth out the silicone sealant as you go. Once you’ve completely filled the gap, give the silicone sealant about 24 hours to dry.

What Type of Silicone Sealant Should I Use for My Next Project?

There’s no definitive answer to this question. In general, your project will determine which type of silicone sealant you use. However, Silicone Depot recommends the Premium 100% RTV Silicone Sealant. It’s made from 100% silicone and comes in a tube that fits nicely into any caulking gun. Before you begin your next project, check out our selection of high-quality silicone products today!