Picture this: you’ve just moved to a nice little cottage by the sea. You’ve got some beautiful views, and you’re literally steps away from the beach. It’s almost like a dream. And then a hurricane hits, and suddenly you’ve woken up from your dream as your little cottage is destroyed by a devastating cocktail of wind, rain, and flood. Instead of moving somewhere a bit further away from the coast, you choose to rebuild. But what do you do, or how do you rebuild, to ensure that this doesn’t happen again?
Coastal regions such as Florida and South Carolina have a long history of getting hit hard (and often) with hurricanes. Over many years of dealing with destruction, flooding, and rebuilding, they’ve discovered three basic principles: elevate structures, build with materials that can get wet, and build structures that can easily dry when that happens. For new buildings, the first levels are typically used for parking, storage, and building access, regions that can afford to get wet. If homes are elevated high enough, then the flooding water won’t get into the bottom floors and cause horrific water damage.
To combat water damage in a building, ventilation is essential. Cavities in a building should be designed to be ventilated, and interior cavities shouldn’t have any insulation (more on that in a bit), and be designed to allow vent openings to be easily provided at the top and bottom.
Buildings, in addition to being elevated, shouldn’t be built out of water-sensitive materials. Florida has been pioneering this movement, with the majority of new buildings in the state being constructed from masonry and concrete. If Floridians want to use water-sensitive materials for aesthetic reasons, they do it smart. For example, if they’re going for a “rustic” look, then they’ll build the first level from masonry, and then the top level will be made of wood. This practice actually has its origins in the Middle Ages, when the bottom levels of structures were made from stone to resist invaders.
Two of the most water-sensitive materials out there are also pretty common in building: paper-faced gypsum board, and fiberglass, used to insulate cavities. To minimize water damage, those have got to go, but they can be replaced pretty painlessly. For example, use non-paper-faced gypsum board on the inside of assemblies and exterior of non-combustible assemblies. Instead of fiberglass cavity installations, install your insulation on the exterior of steel stud assemblies, and design your cavity to be ventilated after water comes along.
When constructing exterior surfaces, avoid both wood and wood-based cladding and trim materials. Instead, look at fiber-cement and plastic composite materials. Make all exterior cladding and trim “back vented”, and if you still absolutely 100% have to use wood trim and cladding, then coat it on all sides before it’s installed to reduce water absorption.