North Carolina General Contractors Practice Exam

How is the thickness of the caulking compound specified for CMU control joints?

1. 1/2 inch

2. 3/8 inch

3. 3/4 inch

4. 1 inch

The correct answer is: 3/4 inch

The specified thickness of the caulking compound for Concrete Masonry Unit (CMU) control joints is set at 3/4 inch due to the need for effective movement accommodation and preventing water infiltration. Caulking serves as a sealant that not only fills the joint to provide a finished appearance but also allows for thermal expansion and contraction of the CMU materials. A thickness of 3/4 inch is appropriate because it offers sufficient flexibility to handle the dynamic forces acting on the CMU structure over time, minimizing the potential for cracking or joint failure. Additionally, using the right thickness ensures that the caulking can properly bond to the sides of the control joint, which is crucial for maintaining the integrity of the building envelope. In contrast, the other thickness options, such as 1/2 inch, 3/8 inch, and 1 inch, would not meet the necessary requirements for expansion and may lead to either insufficient coverage or over-compensation, which could compromise the caulk's effectiveness and longevity.