Patricia Skinner, Bankston, Jr., Joseph D., Reichel, Claudette Hanks | 2/12/2005 1:25:34 AM
Most floodproofing systems have openings that need to be closed and watertight during a flood. A panel closure is any flat, firm sheet material used to block one of these openings. It may be plywood, aluminum, steel, wood planking, plexiglass or any rigid material. It can be permanently attached or designed to be set in place quickly in an emergency.
An opening that needs a closure may be completely clear, such as for a driveway. It may be partially blocked with a door or window that needs additional protection; water may leak between a door or window and its frame or between the frame and the wall.
When floodproofing systems fail, it is often because the closures were improperly designed or installed. In a system designed to hold back 3 feet of water, the panel closure itself must be strong enough to hold back 3 feet of water.
The force from water against a panel is transferred to the frame. In addition to using panels with sufficient strength, be sure the frames and mountings are strong enough to support the panels.
If a panel covers a door or window, the building must be strong enough at that point to resist the force that is transferred to the frame by the panel. If a building is structurally inadequate or weakened by decay or termites, you risk damaging it even further by attempting to floodproof the structure itself. Choose a method that holds water away from the building completely.
Floodgates can be hinged so they swing into place. Heavier gates may be installed on tracks so they glide into position. Either type can be designed to close and seal automatically to protect property from flood damage when no one is home.
Another type of panel closure resides underground and floats into place when its storage compartment fills with water.
Use gasket material in the frame or on the panel. The gasket on a stored panel may last longer than one mounted in the frame and continuously exposed to the weather.
Install a panel so floodwater pushes the panel into its frame more tightly. Install the frame on the water side of the supports so water pressure doesn’t try to unseat it. Use latches or screws to hold panels in place. Latches and thumbscrews that don’t require tools are preferable.
An engineer can estimate the total force on a panel and determine whether a particular material and support structure are strong enough to withstand that force.
See PDF for illustrations.