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Floodplains and Home Elevators: 5 Guidelines You Need to Know

Is your home or project located on a floodplain? FEMA provides specific guidelines to protect against damage when installing elevators in flood zones. Here are the top five.

1. Your Control System Must be Mounted Above the Base Flood Elevation

The Base Flood Elevation (BFE), as defined by FEMA, is the elevation to which floodwater is anticipated to rise during a base flood. BFE is sometimes referred to as the 100-year floodplain. Damage to an elevator due to flooding is more likely if the car, pit, or machine room are below the BFE.

Two primary elevator drive systems are appropriate for floodplain applications. A Hydraulic Drive requires that the machine room be located on a level above BFE. The Inline Gear Drive (IGD) has a motor mounted to the top of the guiderail structure and is by its very nature above BFE. The IGD controller can be mounted inside the elevator shaft at the top of the hoistway or remotely up to 40 feet away from the motor.

2. The Elevator Needs Float Switches

Float switches prevent elevators from entering flooded areas. A float switch indicates to the elevator controller if a measurable amount of water is in the hoistway. If water is present, the float switch keeps the elevator from accessing a flooded floor, which protects the elevator car from water damage.

3. The Elevator Should Retreat to a Level above the BFE

A homing timer automatically returns an elevator to a designated floor. The homing timer can be set to any time from 5 minutes to several hours. This assists in protecting the elevator car from being damaged by flood water by sending the elevator to a level above BFE.

4. Consider Your Elevator Type

The type of elevator you choose has an impact on potential elevator flooding. As noted above, an Inline Gear Drive is situated safely above the elevator.

If you plan to install hydraulic elevators in flood zones, opt for a holeless hydraulic elevator with a jack installed inside the shaft above the BFE. Remember that hydraulic elevator pumps and reservoirs are also vulnerable to flooding and the machine space should therefore be located at a level above BFE.

5. Protecting Elevators from Flood Damage

Careful planning during the installation process reduces the risk of elevator flooding, as can the use of safety features designed specifically for elevators in flood zones. Features that mitigate the risk of elevator flooding include:

  • Constructing elevator shafts or enclosures that extend below the BFE from reinforced masonry or concrete to resist erosion, waves, and scour (when water erodes the ground beneath a structure’s base).
  • When possible, all elevator equipment should be located above the BFE.
  • When possible, all elevator equipment should be located above the BFE.
  • If elevator equipment must be located below the BFE, flood-resistant materials should be used whenever possible.
  • Commercial elevators with fire recall circuitry should send elevators to floors above the BFE.
  • Adequate drainage for elevator pits must be included during construction.
  • Shaftless home elevators are less likely to require equipment installed below the BFE, and are a good choice for residential elevators in flood zones where transport to only two floors is required.

Know Your Local Elevator Codes

Local codes and code enforcement officials’ standards may differ for elevators in flood plains and affect the construction practices of the elevator and shaftway. Contact your local Symmetry Elevating Solutions representative to help determine the best practices for construction and installation for your location. To see complete elevator installation information provided by FEMA, download the Elevator Installation for Buildings Located in Special Flood Hazard Areas in Accordance with the National Flood Insurance Program document.

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