Water damage: covered, excluded, and the line between

Water is the leading cause of homeowners claims by frequency, and the coverage rules are more specific than most policyholders realize.

Generally covered

Sudden and accidental discharge from plumbing, heating, air conditioning or an appliance. A burst pipe, a failed water heater, a supply line to a washing machine letting go.

Accidental overflow, such as an overflowing bathtub.

Water entering through a storm-created opening. If wind removes shingles and rain enters through the resulting hole, the resulting water damage is generally covered.

Firefighting water, as part of a fire loss.

Frozen pipes, generally covered provided the property was heated or the water supply was shut off and drained. Leaving a house unheated in winter and having pipes freeze can void this coverage.

Generally excluded

Flood. Surface water, rising water, storm surge, overflow of any body of water, mudflow. Requires separate flood insurance.

This includes water that accumulates on the ground and enters the house, even if it originated as rain.

Water below the surface of the ground, including water that seeps through foundations, basement walls or floors.

This catches many people. A basement that takes water through the walls during heavy rain is generally an excluded loss.

Sewer and drain backup, excluded from standard policies and available by endorsement.

Sump pump failure and resulting overflow, also typically requiring an endorsement.

Continuous or repeated seepage or leakage over a period of time — commonly defined as fourteen days or more.

This is the exclusion that generates the most disputes. A slow leak inside a wall, discovered months later after causing substantial damage, is generally excluded on the basis that it was not sudden.

Water damage resulting from failure to maintain, including a roof that leaks because it is old.

The sudden versus gradual distinction

Everything turns on this, and adjusters investigate it specifically.

Evidence of gradual damage includes staining with tide lines suggesting repeated wetting, rot, mold growth requiring time to develop, corrosion, and deterioration of building materials beyond what a recent event would cause.

A pipe that burst yesterday produces different physical evidence from one that has dripped for eight months.

Which means prompt discovery and prompt reporting matter, and it means regular inspection of areas prone to hidden leaks — under sinks, around water heaters, at supply line connections, in basements and crawlspaces — has genuine financial value.

Mold

Frequently limited or excluded, with many policies providing a modest sublimit.

Coverage generally depends on whether the mold resulted from a covered cause of loss. Mold following a covered burst pipe may be covered to the sublimit; mold from humidity, condensation or a long-term leak generally is not.

Given remediation costs, sublimits are frequently inadequate, and higher mold limits are available by endorsement in many states.

The endorsements worth adding

Sewer and drain backup coverage. Inexpensive and covers a genuinely common loss, particularly in older neighborhoods, in areas with combined sewers, and in any house with a basement.

Choose a limit that reflects the cost of remediating a finished basement, which is substantial.

Flood insurance, through the federal program or private insurers.

Available outside high-risk zones at much lower cost, and a meaningful share of flood claims occur outside mapped high-risk areas.

Note the waiting period after purchase.

Service line coverage, which covers the buried water and sewer lines from the street to the house — the homeowner's responsibility in most jurisdictions and expensive to replace.

Increased mold limits where available.

Prevention that pays

Insurers increasingly offer discounts for water leak detection devices, and the devices are genuinely effective.

Automatic shutoff valves that detect abnormal flow and close the supply prevent the catastrophic overnight burst, which is the most expensive water loss scenario.

Other measures: replacing rubber washing machine hoses with braided stainless steel, which fail far less often; replacing water heaters proactively at end of life; insulating pipes in unheated spaces; maintaining gutters and grading so water moves away from the foundation; and installing a sump pump with battery backup where relevant.

Shutting off the water supply when leaving for extended periods is free and prevents a large proportion of severe losses.

If it happens

Stop the source. Know where your main shutoff is before you need it.

Document extensively before any cleanup.

Mitigate — extract standing water, dry the area, prevent further damage. Costs are generally reimbursable and mitigation is generally required by the policy.

Act quickly on drying, since mold develops within a day or two and the claim gets substantially more complicated once it does.

Report promptly, and be precise about when the damage was discovered and what you observed.

General information about insurance coverage, not insurance or legal advice. Policy language, exclusions and endorsements vary by insurer and state. Read your own policy and consult a licensed agent.