Once a building has been exposed to a large volume of water, it becomes extremely hazardous as water causes both health and structural risks.

Water Damage Related Health Hazards and Risks
Dampness and humidity promote the growth of moisture-related mold and mildew that can lead to toxic, mold-related reactions such as immune disorders, pathogenic disease and cancer. Allergic reactions consist of painful headaches, disorientation and dizziness, nausea, diarrhea, chronic asthma, rashes and open sores, and chronic fatigue.

Be aware that floodwaters may also be contaminated with sewage and waste. These are fertile breeding ground for disease carrying termites and insect infestation.

Water Related Structural Hazards and Risks
Water saturation affects and damages structures in a few ways.

Direct damage to materials leading to structural instability:

Wallboard disintegrates Structural integrity of concrete is undermined Support columns resting in waterlogged soil slowly twist and tilt Wood swells, warps, and rots Stairs, floors, and roofs may collapse bulging ceilings, indicating trapped water Electrical systems can short out, malfunction, and cause fires or shock.

Leaking LP gas (also known as natural gas) can cause fire or gas poisoning.

Household possessions and interior design can be damaged as follows:

Mud and silt get possessions and valuables dirty Paint and wall coverings peel off Floor tiles are lifted Panels wrap Carpets stain and rot Furnishings such as textiles and furniture stain Books, photographs, paintings become extremely fragile Property value decreases after being wet. Most insulation is ineffective, but it will continue to hold and create high moisture conditions which will damage metal, masonry, and wood.