Many builders and homeowners in the last decade are realizing the advantages of sealing the crawl space under their new construction, retrofitting, or converting the crawlspace under an existing building to a sealed crawl space.
With dehumidifiers operating in the crawl space, usually under the control of a humidistat, such advantages include reduced humidity and a relatively constant temperature in the crawl space, which result in lower heating and cooling bills for the building, reduced mold, fungus, and mildew under the building, and fewer problems from small animals entering through the crawlspace. Conventional air vents are disadvantageous with a sealed crawl space, because dehumidifiers under the building will not work as well with an influx of humid outside air entering the crawl space through conventional air vents.
However, houses and other buildings built in a flood-prone area require some sort of crawl space venting to prevent the building walls from weakening or collapsing during a flood event. Without vents that permit flood waters to flow in and out of the crawlspace under a building, hydrostatic pressure in the crawl space can reach a break point beyond which the building walls may crumble. It has therefore been impossible to seal a crawlspace in a building on a flood plain while complying with government rules and regulations. Up to this point, there have not been any cost-effective vents that obstruct air flow completely and provide insulation, yet allow water to flow into and out of a sealed crawl space.
The Flood Flaps flood vent opens to permit the flow of water in or out of the building when the water level outside (or inside) the building rises, thereby avoiding an excessive pressure differential to develop between the interior and exterior of the building, as well as damage or failure of the building while maintaining a sealed vent when high water conditions do not exist.
Flood Flaps flood vents help protect your home from damage when flooding occurs. After preliminary testing, we determined the flow rate of Flood Flaps to be substantially higher than competitors. This means fewer vents per structure and significant savings on building and insurance costs.
Owners of existing elevated buildings with enclosures below the BFE may wish to retrofit the enclosures as lower NFIP flood insurance rates may apply.
Flood Flaps may be used as a traditional air vent as well on non-sealed crawl spaces and elevated structures. Simply remove the flaps and use in open air crawl spaces while maintaining the high flow rate for flood insurance.
The NFIP Regulations and Building Codes require that any residential building constructed in Flood Zone Type A have the lowest floor, including basements, elevated to or above the Base Flood Elevation (BFE).
Enclosed areas (enclosures) are permitted under elevated buildings provided that they meet certain use restrictions and construction requirements such as the installation of flood vents to allow for the automatic entry and exit of flood waters.