Water Backup
An add-on covering damage when sewers or sump pumps back up — a very common exclusion worth checking.
When a drain does its job in reverse, the water that comes back into the house lands in a gap. Sewer and sump pump backup is a written exclusion in most standard homeowners forms. Water backup is the endorsement that buys that loss back — and without it, the cleanup and repairs typically stay with the homeowner, no matter how high the dwelling limit runs.
The usual causes are ordinary plumbing problems that happen to be someone else's plumbing. A city sewer main clogs. Tree roots crack the pipe running from the house to the street. A long storm overwhelms the system. Or the power goes out and the sump pump stops while the pit keeps filling. The water arrives from below — through floor drains, showers, and toilets.
The coverage is almost always written with its own sub-limit, separate from the rest of the policy — commonly sold in steps such as $5,000, $10,000 or $25,000. That ceiling generally has to cover everything the event ruined: drywall and flooring on the dwelling side, plus furniture and boxes on the personal property side. Some versions carry their own deductible as well.
It is easy to confuse with two neighbors. Flood is surface water arriving from outside, and the home policy excludes it entirely. A pipe that suddenly bursts inside a wall is usually covered with no endorsement at all. Backup sits between them, which is why one wet basement can be covered, excluded, or both at once.
Details vary by insurer and state. Some forms include a sump pump that fails mechanically or loses power; others cover the overflow but not the pump itself. Insurers sometimes ask for a battery backup pump or an alarm before offering the higher limits.
In real life
A storm knocks the power out for six hours. The sump pump stops, the pit fills, and four inches of water spread across a finished basement. Drying and rebuilding runs $9,000, and another $4,000 of stored belongings are ruined — $13,000 in all. The policy carries a $10,000 water backup sub-limit, and that is the ceiling on the whole event, structure and belongings together. It pays $10,000. The remaining $3,000 stays with the homeowner.
Common questions
Does homeowners insurance cover sewer backup?
Generally not on its own. Standard homeowners forms exclude water that backs up through sewers, drains, or a sump pump, no matter how high the dwelling limit is. Most insurers sell the coverage back as an endorsement with its own sub-limit, often in steps like $5,000 or $25,000, and sometimes its own deductible. The endorsement has to be on the policy before the loss happens.
Is water backup the same as flood insurance?
No. Flood generally means water arriving from outside and covering ground that is normally dry, and a standard home policy excludes it — flood coverage is a separate policy through the NFIP or a private carrier. Water backup covers water pushed up through the building's own drains or sump. One storm can cause both at once, and they are handled under two different pieces of paper.
How much water backup coverage can I get?
It varies by insurer and state. The coverage is usually offered in fixed steps rather than matched to the home's value, with figures like $5,000, $10,000 and $25,000 being common and higher tiers available in some places. The sub-limit is a ceiling on the whole loss, including structural repairs and ruined belongings together, so a finished basement reaches it faster than an unfinished one.
See how this shows up on YOUR policy
Upload your declarations page and get a free report card — what's covered, what's missing, and what each gap means in plain English.
Scan my policy — freeRelated terms
Definitions describe how these terms are generally used across the U.S. market. Wording, limits and exclusions vary by insurer, policy form and state — the policy you hold is what controls. See the full Insurance Glossary.