Concrete caulk is a good tool to have on hand if your home has a concrete driveway, sidewalk or patio. Although concrete looks incredibly strong, it can still suffer from cracks and other damage thanks to weather and environmental conditions.
Therefore, concrete requires regular inspection and maintenance to keep it functional, safe and beautiful. Concrete caulk will be your best asset for this purpose. Fortunately, using concrete caulk is easy, even for people who are new to DIY projects. What caulking types exist, and which should you choose as the best outdoor caulk for your concrete repair?
About Urethane Caulk
Most caulks that you'll find in stores are urethane or polyurethane caulks. Like other caulks, this material provides an impermeable adhesive to prevent moisture, air and debris from entering cracks. Unlike silicone caulks, you can paint over urethane caulks, which is an important factor to keep in mind if you plan to paint your patio, porch or other space.
What's the downside of urethane caulk? It degrades over time. Expect to replace it every few years.
Self-Leveling Concrete Caulk
Another type of concrete caulk you'll encounter is called self-leveling caulk. This characteristic means that you do not need a putty knife or other tools to spread and level out the caulk. It naturally spreads to fill in the gaps on horizontal surfaces. It should not be used for vertical or sloped surfaces, as it may be too runny.
Silicone Caulk for Joining Concrete to Other Materials
Silicone represents another popular material to use as a concrete caulk. It does not degrade as fast as the organic urethane caulks, and it remains flexible yet sturdy in its hold.
One of the best uses for silicone caulk involves filling the gaps between concrete and other materials, such as brick, wood or metal. Silicone caulk adheres well to all of these materials, and because it has elasticity, it won't crack or break when materials like wood expand in response to environmental conditions.
How to Caulk Concrete Joints or Cracks
Now that you have chosen the best outdoor caulk for your needs, it's time to get to work.
First, choose a sunny day to perform this task. The caulk needs to dry and cure. Most do this in a matter of hours, but a sudden rain shower or downpour can affect the strength and properties of the caulk. Don't waste your time or money; look at the weather forecast ahead of time.
Second, clean up the area that you'll be caulking. It does not need to be sparkling clean, but it should be free of obvious dust, dirt and debris. Remember, you want the caulk to adhere to the concrete. Anything that gets in the way can affect how well the caulk sticks and does its job.
Evaluate the Size of the Crack or Joint
One thing you don't want to do is waste your caulk by having it sink down into the joint. It doesn't do any good down there.
Instead of filling the entire depth with caulk just to be able to seal off the top, stuff the joint or crack with a foam backing rod. This is a flexible strip of foam that fills the extra space in these joints or cracks, allowing you to apply caulk or sealant to the surface, where it can do its job of keeping moisture and debris at bay.
Apply the Caulk
Cut the tip off of the caulk tube and load it into a caulking gun. Squeeze a bead of caulk into the crack or joint in a smooth, fluid motion. If you don't have self-leveling caulk, you'll want to smooth the caulk and spread it lightly with a tool. Something as simple as the back of a plastic spoon works just fine.
Follow the instructions on the caulk tube regarding drying and curing times before using, painting or hosing down your driveway, patio or sidewalk. That's all there is to it.