What condition will a steel roof beam that is directly exposed to fire experience?

When a steel roof beam is directly exposed to fire, it will become unprotected. This condition arises because the high temperatures associated with fire can cause any protective coatings or insulation on the steel to degrade or be destroyed. As the protective elements are compromised, the steel beam is left vulnerable to the intense heat, which can lead to significant changes in its physical properties.

Steel has a known characteristic where its strength is compromised at elevated temperatures. As it reaches certain critical temperatures, it loses its load-bearing capabilities, eventually leading to structural failure. Therefore, becoming unprotected is a critical condition highlighting the potential danger posed by fire to structural steel elements in a building. This understanding emphasizes the importance of fire protection measures and good fire safety practices in buildings.