Summer/Fall 2013 When the Levee Breaks Flood Vents Protect Homes From Hurricane Sandy The Quest for Greener Landscapes The Evolution of the Sustainable Sites Initiative
By Chris Towery When the Levee Breaks Flood Vents Protect Homes From Hurricane Sandy When Hurricane Irene hit in 2011, the pressure from the floodwaters caused the foundation walls of Justin Kooy s home to collapse, which compromised the structural integrity of his entire house. Kooy wasn t alone, as dozens of his neighbors in Woodbridge, New Jersey, suffered similar damage to their homes. After getting his insurance money, Kooy decided to tear down his old house and rebuild a new one on the same location. In late October 2012, just three weeks after Kooy moved into his new residence, Hurricane Sandy plowed into the New Jersey coastline about 100 miles south of Woodbridge. Sandy devastated large areas of New Jersey and New York, eventually becoming the second-most destructive hurricane ever, surpassed only by Katrina. Once again, Woodbridge was hit hard: code officials found 35 homes in the town with collapsed foundations caused by the floodwaters. Incredibly, while neighboring homes on his block many of which had just been rebuilt following Irene were seriously damaged, Kooy s new home suffered practically no damage at all. Under Pressure One of the primary reasons Kooy s home survived unscathed while many of the neighboring houses were destroyed was thanks to a relatively inexpensive construction product known as flood vents. Flood vents are small (typically 16 x 8 ) engineered openings made from stainless steel or aluminum installed in a home s exterior walls to allow floodwaters to automatically flow in and out of the home s lowest enclosed area. This relieves the intense pressure, known as hydrostatic load, floodwaters exert on the walls, preventing them from collapsing. 10 www.southerndesignandbuilding.org
Kooy installed five flood vents in the walls of his new home s foundation, and while Sandy s floodwaters did ruin some of the ductwork in his crawlspace, the house suffered no structural damage, unlike some of his neighbors who rebuilt their homes without adding flood vents. The flood vents did their job 100 percent, says Kooy. There were houses on my block that had their foundations collapse during Irene, which were then repaired back to the way they were, but they collapsed again during Sandy. Not only did the flood vents protect Kooy s home from damage, they also saved him on his flood insurance premiums. In the old house, we were paying over $2,400 a year in flood insurance, but with the new house that s equipped with the flood vents, the premium went down to just $331 a year. The amount homeowners can save on their flood insurance varies, depending on the home s location, elevation, size, and other factors, but most people can expect to see a fairly dramatic decrease in their premiums by installing flood vents. Over the past 11 years, homeowners have experienced an average of 83-percent savings on their flood insurance premiums by installing our vents, says Tom Little, Vice President of Smart Vent, the brand of flood vents Kooy added to his home. Lack of Education With such benefits, it seems like nearly everyone would want to install flood vents in their homes, but many living in coastal areas have yet to take advantage of the technology. Some people who fail to install flood vents live in older homes, where they assume they re safe, mainly because they ve yet to face a serious flood. For example, many of the regions recently hit by major storm like Sandy are located in floodplains, but since these places haven t seen a substantial hurricane in decades, homeowners weren t aware of the dangers the lack of flood venting posed until it was too late. The lack of knowledge out there is amazing, says Brian Shaw, Business Development Manager of Smart Vent. Right now, many homeowners aren t aware that their homes have inadequate venting until they re faced with a flood. But it s not just the homeowners who are dragging their feet. Another reason people have been slow to adopt flood vents is because local building code officials have been lax in enforcing the laws. Some of this might be attributed to code officials who allowed homeowners to slide, while in other situations, code officials themselves may have lacked the knowledge of proper flood venting requirements. Sometimes even the code officials aren t aware of the danger of non-compliant flood vents, says Shaw. They may have been working in the business for 20 years, but unless a storm hits, the vents they ve been approving never get tested by a flood. In New Jersey, however, code officials became aware of the danger a couple of years ago and began seriously stepping up enforcement of non-compliant flood vents. In Sea Isle City during summer of 2011, the city issued nearly 200 court summonses to homeowners who were not in compliance with the Federal Emergency Management s (FEMA) flood standards. Most of these summonses were issued because of insufficient flood venting, and the homeowners were ordered to bring their homes into compliance or be called before a judge. One reason homes in Sea Isle City were not in compliance was because the FEMA standards had been updated in 2008. In this revision, FEMA imposed stricter requirements for flood vents, so even though homes may have had some type of venting system, the new standards meant that some of these systems were no longer sufficient. Through no fault of anyone, these vents became about one-third less than the standard requires, Sea Isle City Construction Officer Neil Byrne told the Press of Atlantic City. FEMA no longer accepts it. The foundations of Justin Kooy s home were destroyed by Hurricane Irene. Summer/Fall 2013 11
Although most of these homeowners were undoubtedly not very happy about having to pay for the installation of new vents, Byrne said that all of those issued summonses eventually brought their homes into compliance. This proved to be a blessing in disguise when Sandy hit just one year later, none of the homes with the new flood vents suffered structural damage. FEMA Standards According to the FEMA standards of 2008, the part of a home required to have flood venting is any enclosed area, such as crawlspaces or garages, located below the Base Flood Elevation (BFE). FEMA defines the BFE as the level where, in any given year, there is a one-percent chance of floodwaters reaching or exceeding. Any enclosed portion of a home that falls below the BFE must be vented to reduce the chance that the hydrostatic pressure of the floodwaters will cause the walls to collapse. But just because a home has openings where floodwaters can pass through doesn t necessarily mean the A Smart Vent flood vent installed in a home s foundation wall. openings are FEMA compliant. For example, many homes in flood-prone areas have openings on the foundation walls for ventilation, known as air vents, which typically don t meet the standards. This noncompliance can be for several reasons, but one of the main ones is because air vents often have coverings, such as grates, louvers, or grills, that can be opened or closed to increase or decrease the airflow depending on the season. Because these vents require someone to manually open or close them, they are not considered compliant, as FEMA requires that flood vents provide for the automatic entry and exit of floodwaters without human intervention. The only exception to this would be if an air vent s covering has been permanently disabled in the open position. Another reason many air vents fail to comply is because their coverings (grates, grilles, louvers, etc.) decrease the amount of open area for floodwaters to enter and exit, as the portion of the opening that s obstructed by the covering does not count toward the net open area. Moreover, such coverings frequently clog with debris that s swept up in the water. When there s a flood, the water churns up grass, leaves, twigs, and all types of muck that can clog up a typical covering on these air vents, says Shaw. This causes the hydrostatic pressure to build up, and eventually the foundation collapses. Outside of air vents, other openings that do not meet FEMA standards for flood venting include doors, windows, or garage doors, since none of these can automatically open during a flood without human intervention. While it is possible to comply with the FEMA standards for flood venting with air vents or other similar openings, building code officials and flood plain managers recommend that homeowners install true flood vents, which are manufactured specifically to equalize the hydrostatic pressure on foundation walls during floods. Some flood vent manufacturers also make a combination of flood and air vents that satisfy both flood protection and ventilation in a single product. True flood vents are classified by FEMA as engineered openings, versus simple air vents, which are considered non-engineered openings. To be classified as engineered openings, flood vents must be certified in one of two ways: 1) they are certified by a registered professional engineer or architect licensed in the state in which the building is located or 2) the flood vents have been issued an Evaluation Report from the International Code Council Evaluation Service (ICC-ES). To obtain an Evaluation Report, the flood vent must undergo evaluation and testing by the ICC-ES. Once issued, the Evaluation Report certifies the flood vent as an engineered opening 12 www.southerndesignandbuilding.org
In Sea Isle City, during summer of 2011 the city issued nearly 200 court summonses to homeowners who were not in compliance with FEMA s flood standards. in all 50 states, without the need for further certification from local design professionals. Currently, only Smart Vent flood vents have been issued an Evaluation Report by the ICC-ES. Further, FEMA stipulates that there must be at least two openings on two different exterior walls in any enclosed area below BFE. For non-engineered openings, FEMA requires that the flood vents provide one square-inch of net open area for each square foot of enclosed area. For example, if each vent has 42 square inches of net open area, an enclosed area of 1000 square-feet must have 24 vents. This formula must be used because non-engineered vents have not gone through official testing. For engineered openings (ICC-EScertified products), FEMA allows the coverage to be the same as what was achieved during the ICC-ES testing and evaluation. For example, if each vent is rated as providing 200 squarefeet of coverage, an enclosed area of 1000 square-feet must have five flood vents. Additionally, the bottom of each flood vent both engineered and non-engineered must not be higher than 12 inches above the final grade. Vent Function Depending on the company that produces them, there are a few different ways in which flood vents are designed to provide for the automatic entry and exit of floodwaters. One of the simplest designs incorporates a panel covering the vent opening that automatically pops out under a predetermined amount of pressure. Another style of flood vent has a panel covering the vent opening that functions like a doggy door. The panel is hinged at the top and opens at the bottom, allowing for a bi-directional flow of water when pressure reaches a certain level. Rather than relying on water pressure to push the vent open, Smart Vent flood vents feature a patented system of floats that open the vent door when floodwaters rise. These floats are located inside the door, and they keep the vent closed until floodwaters enter and cause them to rise, which automatically unlatches and opens the door. The door is hinged in the middle and can open in either direction, allowing floodwaters to either flow in or out of the enclosed area to relieve the hydrostatic pressure. When there s a flood, water lifts up the floats and unhinges the door, so the vent can open, says Shaw. When the flood door opens up, there s a three-inch clearance on the bottom to let debris get through. The vent is made from all marine-grade stainless steel, so it s not going to rust or corrode. Post-Sandy Changes Following the severe devastation of Hurricane Sandy last year, FEMA is in the process of modifying its flood maps, so the BFE in some regions, especially in New York and New Jersey, is likely to change. This can be stressful for residents looking to invest in flood vents for their homes or make other protective modifications, since the vents cannot be installed without knowing the exact BFE. The situation is bothersome even for residents like Kooy, who have already installed flood vents. In Kooy s case, FEMA has proposed raising the BFE by several feet in his area, which would require him to add even more flood protection, despite the fact that his home survived Sandy with almost no damage. FEMA is looking to raise the BFE by four feet in my area, says Kooy. Now the first floor of my home is going to be one foot under BFE, instead of three feet above it, even though we didn t have any damage from Sandy. It s so frustrating. While the changes to the BFE and other FEMA standards can be difficult for homeowners to deal with, the frequency and strength of storms affecting our coasts has been steadily increasing over the last several years. The destruction caused by recent hurricanes like Irene and Sandy prove that, in many cases, homes and other buildings are unprepared to handle the most powerful of these storms. To this end, although the stepped up standards may be inconvenient, they re ultimately a small price to pay for enhanced safety. The raising of standards since Sandy has definitely been a positive thing, says Byrne. We want to be sure the properties on the shore are the safest and the securest they can be. To read the full text of FEMA s updated flood standards from 2008, visit www.fema. gov/national-flood-insurance-program-2/nfiptechnical-bulletins and download Technical Bulletin 1 Openings in Foundation Walls and Walls of Enclosures. 14 www.southerndesignandbuilding.org