Illinois Roofing Practice Exam

In the case of water build-up due to improper drainage, which of the following is LEAST likely to happen?

1. Damage to the deck

2. Increased weight load on the roof

3. A sudden change in the slope and the strength of the deck

4. Formation of ice dams

The correct answer is: A sudden change in the slope and the strength of the deck

The statement regarding a sudden change in the slope and the strength of the deck is least likely to happen because a roof's slope and structural integrity are determined by its design and construction, which do not suddenly change due to water accumulation. Improper drainage may lead to water pooling, but this does not inherently alter the slope or change the inherent strength of the deck in a sudden manner. Conversely, damage to the deck and increased weight load are direct consequences of water build-up. Prolonged exposure to water can deteriorate roofing materials and weaken the underlying structure, while the weight of standing water adds significant stress to the roofing system. Formation of ice dams is also a concern in certain climates where melting snow and refreezing lead to water trapping, but again, this does not alter the fundamental characteristics of the deck’s slope or strength directly.