Final answer:
Double hot-dipped galvanized or stainless fasteners and specially treated joist hangers are essential in high moisture or corrosive environments to prevent corrosion and maintain structural integrity, especially in outdoor construction.
Step-by-step explanation:
Double hot-dipped galvanized or stainless fasteners and specially treated joist hangers are required in environments that are exposed to high moisture or corrosive elements. This is particularly important in outdoor construction, such as decks and other structures that come into direct contact with the elements. Using these types of fasteners helps to prevent corrosion, which can weaken the structure over time and lead to safety hazards.
In areas with high humidity, coastal regions, or places where de-icing salts are used, the use of double hot-dipped galvanized or stainless steel fasteners and treated joist hangers is especially critical to maintain the integrity of the structure. They provide a higher level of protection against the elements compared to standard fasteners. It is important to follow local building codes and manufacturers' recommendations when selecting fasteners and hangers for construction projects.