While a variety of malfunctions and mishaps may be a potential cause of home water damage, common plumbing leaks are number one. The network of supply plumbing that distributes water under pressure throughout the house, the drain pipes that carry away wastewater, and the various fixtures and appliances connected to this system present many potential scenarios for plumbing leaks.

Because most of the structure inside the attic is wooden, including beams, joists, rafters, and other constituents, roof leaks into the attic usually mean wet wood. Wooden attic structure is often untreated—building codes in many locales do not require it—and may be vulnerable to rot if attic water damage occurs from sources like roof leaks, plumbing pipes, or even high levels of condensation.

Home water damage presents a threat to more than just the house structure and contents. In many cases, home water damage can also be a health hazard to occupants of the house. Water from indoor sources, or water entering from the outdoors, can rapidly become a potential contributor to physical reactions ranging from simple irritation to severe illness.

While summer may bring damaging rain, winter’s the season of home water damage related to frigid weather. During one recent winter, 49 of the 50 states experienced freezing temperatures at some point. Home water damage in winter routinely totals over $1 billion nationwide.

Here are two areas where home water damage frequently occurs in winter, as well as strategies to deal with it.

Unpleasant odors are a frequent side effect in homes and other buildings affected by water damage. Contained within enclosed premises, the cumulative effect of chronic odors on occupants is often greatly intensified. Bad odors can also indicate an actual health threat present in the indoor environment, as well, from toxic contaminants such as mold.

Over-the-ground flooding, also known as surface water flooding, can be a cause of water damage to both the exterior and interior of your home. The definition of over-the-ground flooding is basic: Excess water that has entered—or fallen onto—areas from which it cannot rapidly drain away. It may take the form of flowing water in motion, continuous large puddles on hard surfaces such as a driveway or patio, or a marshy, over-saturated lawn.

If someone poured 18 gallons of water into your house every week, would you be surprised to find that water damage had occurred? That’s the approximate weekly content of water vapor generated inside a home by the daily living activities of a typical family of four. If that invisible vapor condenses into actual liquid, the result can be substantial indoor water damage, seen and unseen.

A water heater failure is a frequent cause of home water damage. At least 75% of water heaters will fail before 12 years of operation. The average cost of damage caused by a ruptured water heater tank exceeds $3,000. For these reasons, most plumbing experts advise preemptive replacement of water heaters when a unit reaches eight to 10 years old.

Flood cleanup after home water damage can be a daunting proposition. What to do first? What next? Minute by minute, water damage keeps getting worse if effective flood cleanup is delayed. Yet, pressure and uncertainty make decisive action difficult. An effective antidote to feeling overwhelmed by a crisis is to set priorities, make a list, and follow it.

Wet walls are an annoyance, a housekeeping issue, and—perhaps—the outward sign of a potentially damaging plumbing event. Most residential walls are constructed from drywall and not intended to resist continuous dampness. In many cases, frequently wet walls will exhibit peeling paint or wallpaper. They may also display conspicuous streaking, stains, or mold growth. In the worst-case scenario, chronically wet walls may warp, sag, or otherwise structurally deteriorate as drywall material is permanently compromised by moisture exposure.