FLOOD07643

• County: Statewide
• Basin: Statewide
• Title: Physical and Economic Feasibility of Nonstructural Flood Plain Management Measures
• Date: 3/1/1978
• Prepared For: US
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Educational/Technical/Reference Information

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CHAPTER 10
CONSTRUCTION MATERIALS AND PRACTICES FOR
NEW OR EXISTING STRUCTURES

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Description
When constructing new structures in a flood hazard area or repairing existing structures,
water resistant materials and damage reducing construction practices are available to reduce
potential damage. Generally, this includes modifying one or more of the following: basement
and/or firsl'floor walls, floors, ceilings; structure exterior walls, insulation, outside utilities; and
electrical, heating and air-conditioning systems. Specific modifications are described below and
in Appendix D.

Basements - The greatest danger to basement walls and floors during flooding is that of
collapse. Rising and receeding flood waters can create excessive hydrostatic forces on basement
walls and floors causing failure. Several actions can be taken to reduce this danger (Figure 10-1).

· Install drains and valves in the foot of walls so water pressure inside and out will be
equalized.

· Use permeable backfill adjacent to walls, floors, and around drains.

· Use water resistant tile, linoleum, carpeting, and plywood.

· Paints and paneling can be of materials which are serviceable after getting wet.

· Basement ceiiings can be constructed with drains to allow drainage between framing joists
and through the ceiling to prevent excessive weight on the drywall.

· Cabinetry can be of metal or exterior plywood and anchored to walls, floors, or ceilings to
prevent flotation.

· Basement stairways can be made wider to facilitate removal of furnishings to higher floors.

First Floor - Paints, paneling, and flooring materials can be selected which are water resistant
and serviceable after contact with floodwaters. Cabinets, bookshelves and other furnishings
which are susceptible to water damage can be constructed of water damage resistant
materials - exterior plywood, metal, or similar materials. Stairways can be made wider to allow
movement of furnishings from the first floor to the second floor.

Exterior and Outside - Superstructures and outside tanks can be anchored to their foundations
to prevent flotation. A manually operated sewer cutoff valve can be installed in the sewer lateral
to prevent backflow from a surcharged sewer. Insulation can be nonabsorbent and all exterior
materials can be "exterior grade" to r~duce possible water damage. Sub-floor joists and wall
studs can also be of lumber which has been treated to repel water.

Electrical, Heating, and Cooling Systems - Actions to reduce water damage to electrical, heating
and cooling systems include: anchoring fuel tanks to prevent flotation; venting fuel tanks to the
outside atmosphere above the first floor to prevent escape of fuel inside; heating and cooling
ducts can be providedwith drains; electrical circuits can be separated to allow closing circuits in
lower areas while leaving them on in upper areas (this allows utilization of electricity in some

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