Acrylic-latex and silicone-based caulk are the two sealants that are commonly used for waterproofing joints, filling gaps, and covering cracks. And while both do the same job, there are significant differences between the two.
Key Takeaway
Acrylic-Latex caulk is inexpensive, will adhere to most materials, including wood, and can be painted over.
Silicone-based caulk offers flexibility, better water resistance, and UV protection, but it cannot be painted and is comparatively expensive.
Understanding the differences between silicone and acrylic-latex caulk will help you make the best-informed decision about which one to buy.
What is Acrylic Latex Caulk?
This is a water-based caulk that is primarily made from acrylic latex which is an organic substance. Acrylic latex is mostly used indoors and offers several advantages.
Latex Caulk Pros
The first and foremost advantage is the versatility of acrylic latex. You will often see this substance used by painters, hence its alternate name of “painter’s caulk,” But there are other advantages as well.
- Easy to Apply
- Can Work on Porous and Nonporous Materials
- Can be Painted Over
- Easy to Clean using Soap and Water
- Best Suited for Gaps that Remain the Same
- Inexpensive
Cons
The downsides include acrylic not being as long-lasting as silicone. But arguably worse is that it is not well-suited for outdoor use unless it has been augmented.
For the most part, acrylic caulk is used indoors where moisture is not as big an issue. However, it can also break down when exposed to ultraviolet light or UV rays, making it a poor choice to use outdoors unless it will be painted over.
What is Silicone Caulk?
Silicone caulk is made from inorganic material and is most often used on surfaces that are outdoors. The benefits of silicone caulk are considerable.
Advantages of Silicone Caulk
The first benefit is its inherent strength. Silicone caulk can last for a long time, even when exposed to UV rays and the elements. It offers other advantages as well.
- Hold Up to Extreme Temperatures and Climate Conditions
- Works on Gaps that Expand and Contract, as well as Stay Constant
- Flexible and elastic material that allows for movement
- Can be applied in low temperatures and withstands a broad temperature range.
- Doesn’t cause discoloration under UV exposure.
However, silicone caulk is more difficult to apply compared to acrylic latex. Plus, only certain types can be painted over. And while it does last considerably longer, it also is more expensive and has a stronger odor compared to acrylic latex caulk.
Cons
- Not easy to work with and difficult to shape.
- Pure silicon is not paintable.
- Hard to repair.
- 100% silicone will not adhere to the wood. (Use polyurethane caulk for wood)
- Expensive compared to latex.
Which Caulk is Better for Your Job?
It’s recommended that you have both types of caulks available since they are used for different types of jobs. But each has its own advantages, so choose the right one for the job.
- When to Go for Acrylic Latex Caulk? If you plan on painting over the surface, then the latex caulk is the better option. Acrylic latex can be used for most, but not all, indoor jobs as it is easy to apply, flexible, and durable if it is not exposed to the elements or UV rays.
- When to Use Silicone Caulk? Silicone is better for areas that are exposed to the elements, such as exterior walls and the roof. Plus, silicone is perfect for the bathroom, particularly to seal toilets and bathtubs that are attached to the wall. When there is a lot of moisture or water present, silicone is ideal.
Silicone caulk adheres to smooth and non-porous surfaces such as ceramic tiles, glass, mirrors, metal surfaces, etc. Because it is an inorganic substance, it is not affected by UV rays.
What Kind of Caulk for Baseboard Trim?
Acrylic latex caulk works best for baseboard, crown molding, and other interior trim. Latex caulk is easy to work with and can be painted to match the wall colors perfectly.
It is simplistic to say that silicone is for outdoor use and acrylic latex is for indoor even if it is mostly true. With new processes, there are hybrid acrylic latex caulks with silicone in the market that can resist UV rays and hold up better in moisture-rich environments.
Dan Miller is a professional toolmaker with extensive experience in the metalworking and tooling industry.
An avid DIY enthusiast and passionate hobbyist woodworker, Dan shares his expert knowledge here.