How to Choose the Right Caulk or Sealant for Your Project

There are many types of caulks and sealants available, so it can be tricky to pick the right one for your bathroom or kitchen project. A good place to start is by understanding the difference between caulk and sealant.

You may have noticed that people use the words"caulk" and "sealant" in similar ways. That's because both are used to fill gaps, cracks, and bonds between materials, like attaching countertops to sink bases. Both products are also used to prevent leaks and can be applied with or without a caulking gun. This is why sealants are often seen as a type of caulk.

What's the Difference Between Caulk and Sealant?

The main difference between caulk and sealant is elasticity.
Caulk is usually made from a mix of latex and acrylic, which makes it more rigid and prone to shrinking after it dries.
Sealants, on the other hand, are more flexible and resistant to water because they are mainly made from silicone. This allows them to expand and contract with temperature changes while still keeping a strong seal. Sealants are perfect for areas with a lot of moisture or where the weather changes frequently, like kitchens, bathrooms, and around doors and windows.

Kingwits Tip: When choosing caulk or sealant, always consider the temperature and moisture levels of the area you're working in.

Now, let's look at some common types of caulks and sealants to help you choose the best one for your project.

Acrylic Sealant

Acrylic sealant is a water-based, paintable option made from acrylic polymers. It's great for indoor use, such as sealing cracks or gaps around windows and doors. If you need a caulk that you can paint to match your walls or trim, acrylic latex caulk is a good choice. It works well in low-moisture areas and cleans up easily.

Silicone Sealant

Silicone sealant (also called rubberized silicone caulk) is flexible and long-lasting. It doesn’t crack, peel, or lose its waterproof barrier, even after a long time. This makes it perfect for wet areas like showers, bathtubs, sinks, and toilets. Silicone is also a good option for outdoor projects, as it resists moisture and harsh weather. However, it can’t be painted and usually comes in clear or white colors.

Polyurethane Sealant

Polyurethane (PU) sealant is a strong, flexible product that bonds well to many surfaces. It's often used in construction because of its durability and ability to handle tough conditions. PU sealants are great for waterproofing and protecting against water, dirt, and UV damage.

MS Polymer

MS polymer, or hybrid sealant, is a newer type that combines features of silicone and polyurethane. It’s moisture-curing, easy to apply, and environmentally friendly because it doesn’t contain solvents. MS sealants are known for being durable and versatile.