Concrete Caulking FAQ: What You Need to Know

Find the answers to some of the most common concrete caulking questions.

If you’ve noticed cracks or gaps between your concrete slabs, you might be wondering about your options for repair.

Concrete caulking is a practical solution that seals these gaps and cracks, protecting your concrete from the elements and preventing further damage.

At A-1 Concrete Leveling, we’ve spent over 30 years perfecting the art of concrete maintenance, including caulking. We've compiled answers to some of the most common questions about concrete caulking to help you make an informed decision.

1. What is concrete caulk used for?

Concrete caulk is versatile and can be used to seal cracks, gaps, and joints in concrete surfaces. This helps prevent water damage, pest intrusion, and potential trip hazards. Sealing these gaps also protects the base of your concrete slab from erosion, which can lead to settling and uneven surfaces.

In commercial settings, concrete caulk is often used preventatively to protect joints between slabs from water intrusion. Many people opt to caulk new concrete before it has even cracked or separated. It’s also beneficial for maintaining a clean, uniform appearance, especially in high-traffic areas.

2. Who does concrete caulking?

Concrete caulking can be performed by a variety of professionals, including companies that specialize in concrete caulking, general concrete repair and maintenance companies, masons, and even handymen. Some homeowners may even choose to tackle caulking as a DIY project.

Specialized caulking companies often handle large commercial jobs, such as those in shopping centers and warehouses. Masons and general repair companies typically focus on residential properties.

Here at A-1 Concrete Leveling, many of our locations are prepared to support both residential and commercial clients with concrete caulking and repair needs.

3. Does caulking stick to concrete?

Yes, caulking does adhere to concrete, but it doesn’t last forever. The longevity of the concrete caulk depends on environmental conditions, particularly the frequency of freeze-thaw cycles. Over time, the caulk may lose its adhesion and require replacement.

If the caulk was applied correctly—by grinding the crack or gap and ensuring the caulk is placed inside rather than on the surface—it can be removed and replaced when needed. This maintenance keeps the concrete protected and prolongs its lifespan.

4. Is concrete caulk waterproof?

Concrete caulk is designed to be waterproof, creating a barrier that prevents water from seeping through cracks and gaps in the concrete. However, over time, caulk can shrink or pull away from the concrete, especially in areas with significant temperature fluctuations. When this happens, gaps can form, allowing water to penetrate.

Regular inspections and maintenance are crucial to ensure your caulk remains waterproof. As long as the caulk is intact and properly adhered to the concrete, it will continue to provide a waterproof seal.

5. What’s the difference between concrete caulking and sealing?

While both caulking and sealing are essential concrete maintenance practices, they serve different purposes. (Note: These terms are often mistakenly used interchangeably.)

• Concrete caulking involves applying a polymer caulk to seal gaps and cracks in the concrete. This prevents water, pests, and weeds from entering these spaces. 
• Concrete sealing  involves applying a liquid sealant to the entire surface of the concrete. This creates a barrier that protects against water and other liquids that can seep into the concrete’s pores and cause damage.

Both practices are important for preserving the integrity of your concrete, but they address different types of protection.

6. What kind of caulk should be used on concrete?

It’s important to use a high-quality caulk designed specifically for concrete. Polyurethane, hybrid-polyurethanes, and other polymer-based caulks are commonly recommended because of their durability,flexibility, and strong adhesive properties.

These types of caulk provide strong adhesion to concrete surfaces and can withstand natural expansion and contraction with temperature fluctuations, ensuring a long-lasting seal.

Pro Tip: Rigid compounds, like concrete patches or mortar, don’t bond well to the concrete itself or expand and contract with the concrete slab. This lack of flexibility and poor adhesion causes the rigid compound to crack and break off relatively quickly.

7. How do you permanently fix cracks in concrete?

Unfortunately, once the concrete has cracked, there’s no way to make that crack go away completely or permanently unless the slab itself is replaced altogether.

However, concrete caulk can last many years, and when applied correctly it can blend in well with the surrounding concrete.

8. Can you caulk concrete joints?

Yes, caulking concrete joints is essential to prevent water from seeping into the gaps between slabs. This helps protect the concrete from damage caused by freeze-thaw cycles and helps keep the slabs from settling and forming trip hazards.

Caulking joints is especially important in areas that receive a lot of water runoff or rain.

Most people feel the need to caulk cracks because they clearly see the concrete is broken and needs to be repaired, but joints are also gaps that water can seep into and they should be caulked to keep water out, as well.

7. Should you caulk your concrete?

Yes, caulking your concrete is a crucial maintenance step that helps protect it from water damage, pest infestation, and further cracking.

Caulking is especially important for areas exposed to the elements, especially water flow. Regular caulking can extend the life of your concrete by preventing small issues from becoming larger, more costly problems.

Learn More About Concrete Caulking

Now that you have a better understanding of concrete caulking, you can decide if it’s the right option for addressing gaps, cracks, and joints in your concrete.

At A-1 Concrete Leveling, we believe in the importance of proper caulking as part of regular concrete maintenance. For more detailed information on concrete care, visit Concrete Academy. 

Check out some of these related Concrete Academy topics:

• Should You Caulk Concrete Control and Expansion Joints?
• All About Concrete Settling Due to Water Erosion
• Reasons Why Concrete Cleaning & Sealing May Be Right For You
• Concrete Cleaning and Power Washing

If you are interested in learning what concrete caulking can do for your specific situation, request a free onsite cost estimate with an A-1 expert near you!*

*Not all locations offer caulking as a service.