Friday, I was at an event organized by the National Association of Women in Construction (NAWIC). It was a fun event where I got to talk to a group of women who are also in the construction field or related support services. It was at the AC Hotel by Marriott at Dadeland.
I got to chatting with one of the women who is an insurance agent for commercial insurance for contractors about the devastation on the West Coast of Florida. She was telling me that only about 10% of the houses out there were insured for flood. Flood insurance is very cheap, and she didn’t understand how you could live next to the ocean and not get flood insurance. Really, it’s truly hard to believe. She added that the losses are in the trillions of dollars.
What I don’t understand is why we are still allowing houses to be built with wood frame construction. Even in South Florida, we have wood-framed roofs for most single-family homes.
I recall Hurricane Andrew. As a Miami architect, I saw the devastation from Hurricane Andrew first-hand. I was there 24 hours after the hurricane hit the area of Homestead and the southern parts of Miami. Later, I heard the report from the engineers who were hired to do an analysis of what caused all the damage. There were only about 6 major things:
(1) Unbraced gable ends. One truss would knock down the next truss and that truss would knock down the next truss until there were no trusses left supporting the roof. This can be easily prevented by bracing the first truss from the attic.
(2) No reinforcing at the corners which led to houses twisting off their footings.
(3) Windows and doors were blown off. Once you lose your windows and doors, the wind comes in and tears up your house. (4) Roofing tiles or shingles and/or the roofing membrane below being blown off. This would lead to raining inside the house.
(5) Plywood would be ripped off the roof because of inadequate nailing or screwing. Oriental strand board as a substitute for the plywood sheathing would disintegrate when it got wet.
(6) Wood-framed second floors which were not correctly tied to the concrete tie-beam below. I saw many houses which looked perfect from the front because for some reason the second-floor front façade held, but when I walked around the house, there were no second-floor walls on the other three sides.
In residential Miami architecture, the connections from the wood-framed portions of a house to the concrete tie-beams are of the utmost importance . In many cases during Andrew, these connections were flawed and the buildings failed.
In South Florida, we require strapping from wood members to the concrete tie-beams. We now require the plywood to be screwed every 6 inches along the trusses. Our construction systems are better than they were in 1995. We have improved the roofing systems so that roof tiles have a better adhesion method. But I still ask myself why we are using wood at all.
If you look at the photo above from NOAA Hurricane Imagery you can see the destruction. Can we do better? Can we change some of our construction methods so that next time we have a hurricane, people don’t die and houses stand up better? Let’s see what is proposed in the new Florida Building Code which will be implemented in 2023.
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