Final answer:
A second inspection of a building on a slab foundation should be done after significant events such as earthquakes, floods, or nearby construction that could affect the building's integrity, as well as when structural issues are observed.
Step-by-step explanation:
You should make a second inspection of a building on a slab foundation after any significant event that could potentially affect the integrity of the structure. These events include natural disasters like earthquakes and floods, substantial nearby construction activities that might cause ground vibrations or alteration in water table levels, or after a period where the building has shown signs of structural issues like unusual cracking or settling. Performing such inspections can help in early identification of issues, allowing for preventative measures to be taken before they worsen, ensuring the safety and longevity of the building.