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Building Inspections in Haiti

Erica Fischer reports on construction challenges facing post-earthquake Haiti

The earthquake that hit Haiti on January 12th was described as a “middle-class disaster.” I was not sure what that meant until I arrived in Port-au-Prince on March 20th and began doing building assessments with the ATC-20 guidelines. Those who could afford proper building materials, a structural engineer to design their house, and a skilled mason to build the house, had homes which were in pristine condition. These people are considered the upper class.

Those who could not afford proper building materials, and either built the house themselves, or had a mason who did not know proper construction methods, were left with collapses and damages beyond repair. This group was the middle class.

House in Delmas 31: owner would like to try and repair instead of rebuilding.

During my time in Haiti, I saw three different types of houses:

1. Multiple story concrete frame with masonry infill and cast-in-place concrete roof.

2. One story concrete columns with masonry walls and light-gauge metal deck roof.

3. Timber frame with stone infill and wood roof.

Each type of construction had houses that had collapsed and houses that are still standing.

Haitians build their houses in stages: what they can afford at first and then add on floors and additions as they make and save more money. Unlike Americans, no one in Haiti has a mortgage. Those who do not rent own their houses, which made the destruction that more difficult to bear. Unfortunately, in many cases, the original portion of the house was not designed for additional floors to be put on top. Nor was the house, on the whole, designed to withstand an earthquake—let alone one with a magnitude of 7.0.

House in Delmas 33, which was built with column rebar extended for a future addition. Homes in Haiti are built with cash. When owners can afford more, they add on.

Multiple story concrete frame with masonry infill and cast-in-place concrete roofs

House in Delmas 24: concrete columns and beams built first, then the masonry infill is installed.

Houses that are concrete frame with masonry infill were constructed in two different ways:

1. Place the concrete for the columns and beams and then infill the openings with masonry.

2. Build the masonry walls and then place the concrete for the beams and columns.

When the beams and the columns are placed first, there is no connection between the masonry and the concrete frame, and thus the building does not perform compositely. I found, in this instance, that there were cracks along where the ceiling meets the walls and where the walls intersect. This was a result of the plaster coating the masonry and the columns cracking because there was no connection between the two.

On the other hand, when the CMU walls were built first, and then the concrete placed for the beams and columns, the concrete was able to fill the voids of the masonry, thereby making a connection between the columns, beams, and the masonry walls. This allowed the building to work compositely. In these buildings I did not see cracks at the corners, nor where the slab met the walls. In all, these buildings performed much better than those built using the first method.

CMU blocks in Delmas 95 made of poor concrete.

Especially with this type of construction, it is crucial to have a skilled mason or a structural engineer involved. The majority of those who could not afford a structural engineer, or did not use a skilled mason, found their homes in shambles after the earthquake. Nevertheless, structural engineers and skilled masons are expensive, and when money is not available to hire them, Haitians will build homes themselves. When this happens, the concrete is usually poorly mixed and will crumble easily.

There are many different factors that go into the construction of a concrete and masonry building. The type of aggregate used in the concrete, the amount of water added to the concrete, the size of the mortar joints in the masonry walls, how the concrete is mixed, and many others. In the United States, there are strict rules for the design-mix used in concrete buildings. Laboratories must submit mix designs to the structural engineer far in advance of placing the concrete itself. In New York, for example, concrete contractors and laboratories are required to sign off on each mix design with the Department of Buildings. In Haiti, there is little-to-no quality control on concrete mixes or designs.

Mixing of concrete for columns and beams.

One story concrete columns with masonry walls and light-gauge metal deck roof

The second type of building I saw was made of concrete columns, masonry infill, and then a wood framed metal corrugated deck roof. These buildings were built in two ways, just as the concrete frame with masonry infill buildings were built: columns first and then masonry infill wall; or walls first and then concrete columns. In these types of buildings, there are no beams on the top of the walls and, therefore, most of the walls collapsed. These walls were not confined masonry walls, but cantilevered walls that were not braced on the top. The metal roofs were tied into the structure by taking the rebar in the columns, if there was any, and wrapping it around the wood framing for the roof. In most cases, the roofs were not tied into the structure, which resulted in partial or full collapses.

House in Delmas 95: concrete columns with masonry infill. There are no concrete beams on top to confine the masonry.
Typical connection from concrete columns to wood framed metal deck roof.

In an earthquake it is important to have a light-weight structure. Earthquakes are attracted to mass, so the more your structure weighs, the more force an earthquake will exert on it. A metal corrugated deck roof with wood framing is a great way to reduce the mass of your structure. However, when the roof is not properly tied in, it won’t act to brace the top of the walls. When the walls are not braced on the top, the walls act as a vertical cantilevered beam instead of properly supporting the structure.

 

Timber frame with stone infill and wood roof

Wood framed house in Grand Goave; there was no structural damage to the house from the earthquake.

The third type of building structure—which I saw more frequently outside of Port-au-Prince—was timber framed with stone infill. These buildings were very interesting because, as I approached the structure for an inspection, I would notice the building was leaning. I soon learned that the wood used for the timber construction was not straight, and instead of straightening the wood, the builders constructed the house to the shape of the wood: on a slant. After a timber frame was erected, stones were stacked for infill, and then everything was plastered over. These structures were very lightweight, and since earthquakes are attracted to mass, these buildings, on the whole, fared very well.

Wood framed house in Leogane which did not survive the earthquake.

However, being lightweight isn’t always enough to save a structure, and houses which were not built with skilled labor, or with a proper grade lumber, sustained significant damage.

Wood construction has its pros and cons, yet one of the advantages is that less quality control is required. A skilled laborer is not necessarily required when building a wood home, which, for those who cannot afford a skilled laborer, allows people to build their own homes. This is important to keep in mind when it comes to rebuilding the country.

A major disadvantage to wood construction is, of course, deforestation. This is especially true in Haiti, where the country is already 98% deforested. Current rebuilding efforts involving wood construction are importing wood from the United States to Port-au-Prince. With the various taxes and fees imposed at the port, this is not a sustainable method for low income housing. Future rebuilding efforts will have to use products produced or grown within the country itself. Many different organizations have begun to look into light gauge steel as a source of material. Light gauge steel has the same advantages as wood: easy for people to build with themselves, and low quality control.

No matter what the future building material of Haiti is, it will need to be something that is lightweight, easy for people to build with themselves, and produced in Haiti itself.

Despite any damage that had occurred, all the residents I encountered were very proud of their homes. I felt honored that the Haitian people invited me into their homes and private spaces to look around. I would say that the most rewarding part of the trip was being able to tell a family that their house was safe and they no longer had to sleep outside.

———

AUTHOR BIO

Erica Fischer, an Engineer at Murray Engineering PC’s New York office, has worked as a structural engineer in New York City for three years.

Born and raised in Pound Ridge, NY, Erica grew up a Yankees and Giants fan. Not wanting to venture far from her New York roots, she attended Cornell University, graduating with a Bachelor of Science in Civil Engineering. After moving to New York City, her work has focused on high-end cultural renovations and new residential buildings.

Erica’s renovation experience concentrates on residential and theater renovations. In addition to working on the structural design of the David H. Koch Theater at Lincoln Center, Erica has worked on a variety of residential and mixed-use, high-rise buildings throughout New York.

Erica is currently chair of several committees for the Structural Engineers Association of New York (SEAoNY) including the Programs Committee Co-Chair, University Outreach Committee Chair, and the Sponsorship Committee Chair. Through these roles she helps plan the SEAoNY monthly lecture series at the Center for Architecture in New York as well as full day seminars for SEAoNY. She also plans SEAoNY university lectures in New York, where young members speak to students about current significant projects under construction.

Erica will be attending Purdue University this fall for her Masters of Science in Civil Engineering.

Comments/Discussion

12 Responses to “Building Inspections in Haiti”

  1. Gary Katz

    Erica,
    Thank you for sharing your story and photographs! We have another author, an architect and project manager, who is working on a similar story, exploring concrete versus wood construction in Haiti, along with deforestation. We hope to publish that story in a few more weeks!
    Gary

    Reply
  2. Eric Tavitian

    Erica,
    This was a great view into the way the Haitians have been building their houses in past. I grew up in Boston and did my apprenticeship there. I have been a licensed contractor here in Southern California since the 80s. After learning to build structures a certain way for so long it’s hard to conceive that people in other countries don’t have the fail safes we have here and invite disaster. One thing is for sure, Haiti needs to improve the building regulations for the rebuild that’s coming. Are there any plans for the country of Haiti to beef up their inspection force so that the next earthquake won’t have such a devastating affect?

    Reply
  3. Joe Lopes

    Thanks SOOOO much for the informative article. What needs do they still have that we can help with? I suspect the need is mostly financial and of course is the easiest to help with for those of us who can’t go there. But the concern is always that if the finances actually are getting to where they are needed the most. Any suggestions?

    Again, thanks for the report and the sensativity it was written with.

    Reply
  4. Raymond T, McConnell

    These people are not getting the money or building permits from the government to do anything. Money buys a better home. Work done with improper building will fail.

    Reply
  5. Erica Fischer

    The UN is working with the country of Haiti in order to create a Building Department that will have building inspectors that need to follow strict guidelines. I think that it is something that will be developed over time and I am not sure about the details. As far as I know no new construction is allowed in Haiti right now until this department can be formed and there can be a standard of construction.

    In terms of money the hardest part is that the middle class builds their homes themselves. There are some organizations out there that are teaching Haitians how to build correctly such as AIDG and Build Change. Both of these organizations employ American Engineers and Masons to help train Haitians. I am sure there are more out there but these are the ones that I have been aware of.

    Reply
  6. Sim Ayers

    Erica, great article on the effects of being middle-class in an earthquake disaster. Next time I’m over budget on structural hardware, I’ll tie off my beams with rebar for the continous load path.

    Reply
  7. Teeg Merchant

    Erica,
    Thank you for the excellent synopsis of the various Haitian construction methods and their responses to a severe earthquake. Before my father (an architect) passed away he was working a prefab panel system of light steel studs and 1/2″ cement board plus drywall (do they have drywall in Hati?). This results in a versatile and light weight wall system that with proper shear detailing will be structually sound, fireproof, moisture resistant and impervious to insect attack. Plumbing and electrical are greatly faciltated as well. Moisture barrier, stucco and interior finishes are on site work. Foundation/floor is of course dependant on site conditions but any thing from slab to pier blocks on poured pads works. My dad planned on a steel moment frame but he envisioned centralized fabrication (though in country) of almost all components.
    Thanks again for your article and good fortune to the Hatians
    Teeg Merchant

    Reply
  8. MacMarty15221

    @Teeg – Your late father’s system sounds very interesting. I’ve recently been wondering if the standardized designs of Katrina Cottages would apply well in Haiti, perhaps using your father’s materials rather than wood. Do you have any thoughts? It’s easy and perhaps inappropriate for me to judge from here, (and I’m a layman, not a builder or engineer,) but the photos of concrete being mixed on a floor just SHOUT that prefab components could be made more uniformly for improved strength, and still be affordable and attractive to the middle class folks being described.

    Reply
    • Teeg Merchant

      MacMarty,
      Your observation about standardizing is the fundamental underpinning of modular building systems. A uniform panel size based on common component material sizes and assembled into standard (and simple!) sizes of structure is the key to success. A rigorous commitmant to these factors eliminates error at every step of the way. Materials are delivered to a centrally located facility where local labor assembles the panels (I think my fathers envisioned 5 : exterior wall-w/ or w/o door or window and interior w/ or w/o door, all the same size) on jigs and loads them and the other components onto trucks. At the site, AFTER local labor has completed the utilities, (wells, water lines and sceptic) as well as the foundations, to the satisfaction of a foreman/supervisor/inspector (not a job description that would fly in the U.S. is it ?) the complete building packages-panels, drywall, stucco, solar panels, propane tank, windows, paint, cabinets, romex, soft copper (no brazing) roofing, appliances etc. etc. are delivered to the owners who are now responsible for the materials that will become their homes. The local crews who built the foundations would assist with assembly and some finishing but the owner is going to have some serious sweat equity in that building! Though some tools would be included with delivery and remain the owners property (they can repair their house) the larger and specialized tools are with the local construction crews (these guys would become the re-model contractors of the future). Necesscity dictates that these structures will be cookie cutter plans, (although certainly more than one plan) but nothing prevents a multiplicity of options, chosen by the owners in regards to paint, linoleaum, cabinet style (Ikea anyone) or even light fixtures. My father believed that if impovrished populations could live in dwellings where vermin were kept outside, good hygiene became possible, the women didn’t have to haul water or the men firewood and the children could study at night, that decreased disease, increased literacy and ultimately social stability and prosperity would follow as a matter of course.
      Once the program was underway (which is also streamlined and simple) these buildings would be cheap and simple to erect. They would go up at an astonishing rate.
      May something like it happen soon for Haiti and elsewhere TGM

      Reply
      • Andy

        I am a Los Angeles architect and I just returned from a two week vacation in Haiti. As an LA architect, I have more than a passing familiarity with seismic design. There were two things that caught my eye, here.

        First, Erika, is that your essay very closely resembles my own “shoot-from-the-hip analysis of the types of seismic building failures in Haiti. Excellent essay so there is no need to repeat the details of mine here.

        Second, Teeg, I love your excitement for the wall panel system. I had taken an interest in that system for a project here in California about five years ago. I never found a client who would let me “experiment” on them. So I put that idea away… for the time being.

        Three weeks ago, while driving through Port-au-Prince surveying the disaster, I noticed something rather interesting. All of the concrete telephone poles were intact. Concrete poles would have been too expensive to ship so I assumed they were made locally. The next day at a party, by rather extraordinary coincidence, I met a friend of the company owner.

        I’m sure it’s obvious but what is significant about the telephone poles is that I now know that there is somebody in Haiti who is experience with and equipped to produce prefabricated structural concrete products… such as panels. (Structural you ask? Remember that a telephone pole is just a vertically cantilevered beam)

        I am planning a return trip soon to explore this idea a bit further. But the challenges are epic and there is nothing that can be taken for granted in Haiti. What is an appropriate roofing system? I wouldn’t use wood because that requires a waterproof roof. Even if Asphalt shingles were available they are expensive, have a short life cycle in the climate and almost certainly will not be repaired or replaces appropriately. (Remember, minimum wage is $5.50 – even a $500 roof replacement would be prohibitive.) A corrugated steel roof would cook the occupants in short order… then rust. In order to save money, how often will the insulation be left out of the wall cavities, further cooking the family. Since stud-frame construction is rare, wouldn’t fiberglass bat be equally rare. Do we use drywall (a more “exotic’) material or do we use stucco for the interior walls.

        The one thing that the concrete construction did do well was to keep people cool and never rotted.

        I share your enthusiasm for the panel system but the laundry list of questions could run on for as long as I have time to type. In reality, I am not that qualified to design solutions for Haiti. I have too much cultural and technological baggage. What I will do is go to Haiti, build a small sample panel in the corner of a telephone pole manufacture’s lot and ask them “So, what do you think we can do with this?”

        “Vacation in Haiti? you ask? Not most people’s first choice but they have 8,000′ mountains surrounded by stunning Caribbean Seas. We forget that this is also a stunningly beautiful island and the people are gracious and friendly. If you really want to help Haiti, spend a week on Ile la Vache or at a resort near Cap Haitian.

        Reply

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