Landscaping License Practice Test

What is the recommended spacing for expansion joints in a concrete slab?

1. 5 ft apart

2. Every 10 ft in all directions

3. 2 ft apart

4. 3 ft apart

The correct answer is: Every 10 ft in all directions

The recommended spacing for expansion joints in a concrete slab is typically every 10 feet in all directions. This spacing helps to accommodate the natural expansion and contraction of the concrete due to temperature changes and moisture variations. When concrete slabs heat up, they tend to expand, and when they cool down, they contract. By placing expansion joints at this interval, you allow for movement without the risk of cracking, which can occur if the concrete is restrained. In addition, having expansion joints at consistent intervals creates a more uniform and manageable method for dealing with movement throughout the slab. It also simplifies maintenance and repair efforts, while enhancing the structural integrity of the overall paving or flooring system. Other suggested spacings, such as 2 feet or 3 feet, might not provide sufficient accommodation for the stresses that can occur with larger slabs, leading to increased risks of cracking. Therefore, specifying every 10 feet in all directions achieves an effective balance in managing the physical characteristics of concrete.