Which type of construction has a rating of two hours or more and has the most favorable fire rating?

Fire resistive construction is specifically designed to withstand fire for a specified period, usually two hours or more. This construction type utilizes materials that can maintain structural integrity and limit the spread of fire and smoke during that critical time. The use of reinforced concrete, gypsum, and other fire-resistant materials ensures that the building can withstand intense heat and flames, thereby providing occupants critical time to evacuate and enhancing overall safety during a fire incident.

In contrast, light frame construction typically has a lower fire rating due to the use of wood and other combustible materials, which can ignite and spread flames more quickly. Ordinary construction, while more durable than light frame, also does not meet the heightened fire resistance standards of fire resistive construction. Non-combustible construction involves materials that do not burn but may not necessarily provide the same structural integrity under extreme fire conditions, making it less effective than fire resistive when considering the comprehensive rating that includes time durability against fire exposure. Therefore, fire resistive construction is recognized for its superior fire protection capabilities among the provided options.