There is a 99% chance that if you live in Los Angeles, your wood frame home survived the 1994 Northridge earthquake. It was a magnitude 6.7 event, caused $20 billion in damage, and seventy-two deaths. The damage to homes was primarily stucco cracks at door and window openings, and un-reinforced masonry chimney failures. There was a surge in demand for foundation bolting and bracing after the earthquake, but even before building codes accounted for seismic events, our wood frame homes were both strong and flexible; two characteristics that are essential to surviving a temblor.
Look closely at the photos from Haiti. You will see slabs of broken concrete with little, if any, reinforcing steel. Concrete is strong, when made properly, and reinforcing steel is flexible. The difficulty with concrete construction is it requires sophisticated engineering, quality control for the concrete mixture, and meticulous execution. Without those measures, the result of a 7.0 earthquake—as occurred in Haiti on January 12, 2010—is catastrophe.
When the first concrete truck arrived at the last project I inspected as an ACI Field Technician, I checked what time the driver left the batch plant, how much water he added in transit, and how many revolutions the drum had turned. Then I tested for temperature, slump, and air content; all according to ASTM Standards. Finally, I made test cylinders for laboratory compression testing. I repeated this process throughout the day as new loads arrived.
Quality control at the batch plant is similarly regulated, as is the production of cement and aggregate. It’s a demanding process that cannot be relaxed, if the goal is to achieve the performance in the field that the engineer calculated on paper. Unfortunately, it’s a process that does not occur in many countries.
Quality control is not as stringent in some countries as it is in others. This can have unfortunate consequences down the road.
Over 80,000 people died in the 2008 Sichuan earthquake, including thousands of school children, and it’s a tragedy all-too-often repeated around the world. The reoccurring theme is improperly engineered and constructed concrete and masonry (concrete block, brick, mud, etc.). A stunning exception to this was the February 2010 earthquake in Chile which was 500 times more powerful than the one in Haiti, and moved the entire city of Concepción ten feet to the west. Were it not for the implementation of building codes years prior, the fatalities would have been in the thousands instead of the hundreds.
The per capita income in Chile is over $14,000. In Haiti it’s $1,300. Chile has the resources to enforce building codes. Haiti does not. According to a 2003 census, the official population of Port-au-Prince was just over 700,000. The population of the hillside slums surrounding the city was over 2,000,000. Construction in the slums is unregulated: there is no building department and no infrastructure.
Homes in Haiti are not wood frame because there are no trees. According to the Library of Congress Federal Research Division, over 60% of Haiti’s land was forested in 1923. By 2006, 98% of the country was deforested. What happened?
French colonialists stripped the country of Mahogany, and Haitians cut down most of the remaining trees for charcoal. The demand for charcoal—made from burning trees—skyrocketed as population increased in Port-au-Prince. Charcoal is used as a cooking fuel and its use contributes to deforestation—and global warming—worldwide. Breathing indoor cooking fumes is the number one cause of child deaths in the world.
The country is now an example of societal failure due to environmental degradation, as Jared Diamond, professor of geography at UCLA, describes in Collapse: How Societies Choose to Fail or Succeed. The way out is reforestation and finding alternatives to charcoal. Amy Smith, an engineering professor from MIT, and recipient of a MacArthur “genius” grant, has developed a method of making low-smoke charcoal from agricultural waste, and much of her research has focused on Haiti. Her method is affordable and sustainable. In the meantime, how should Haiti rebuild?
Wood construction costs less than concrete, masonry, or steel. It is also the only building material that is a renewable resource and naturally absorbs carbon dioxide from the atmosphere, thus mitigating global warming. Wood framing has a distinct advantage over other building materials when it comes to achieving structural integrity: it’s easier to engineer, construct, and inspect. A 7-story wood frame condominium tower underwent a simulated 7.5 magnitude earthquake at a laboratory in Japan, and survived with little damage. The building was outfitted with metal connectors that any carpenter can install. Similar connectors are used for hurricane resistance.
What’s the downside? The unregulated construction in the slums of Port-au-Prince is not only a public health hazard but also a fire hazard. Buildings lack proper separation, there are impassable clearances, and limited fire-fighting infrastructure. As rebuilding takes shape, these issues need to be addressed.
In the face of earthquakes, hurricanes, and global warming, the need for wood construction and reforestation has never been greater. It is time to turn to the ingenuity and ability of American carpenters, and bring our greatest resource to the world: experience, strength, and hope.
Gary Goldblum left architecture to go to trade school and become a carpenter. He went on to be a superintendent and building inspector, and returned to architecture decades later after becoming wheelchair-bound. He now works as a senior project architect and specifications writer for Harley Ellis Devereaux in Los Angeles. He has written about energy efficiency and photovoltaic design for Home Energy, Solar Today, and The Construction Specifier, and is passionate about wood construction and reforestation.