What term is associated with construction that protects against entry of water from heavy rain?

The term "rain tight" specifically denotes construction methods and materials that are designed to prevent water from entering a structure, even during heavy rainfall. This implies that the building or component has been engineered to resist water infiltration effectively, utilizing various design strategies such as proper sealing, sloping surfaces, and the use of water-resistant materials. The concept of rain tightness encompasses not only the integrity of the materials but also the workmanship and installation methods employed to ensure that water cannot penetrate the building envelope, thereby protecting the interior from potential water damage.

The other terms may suggest varying degrees of water resistance but do not provide the same level of assurance as "rain tight." For example, "rainproof" and "rain-resistant" may imply some level of protection but can sometimes be interpreted as less stringent than being truly rain tight. "NEMA 3R" refers to a rating for enclosures intended for outdoor use that can withstand rain, but it may not specifically denote the level of protection against water entry as clearly as "rain tight."