Does homeowners insurance cover sewer backup?

Usually only with an add-on. Most standard policies exclude water that backs up through sewers, drains or a sump pump. To cover it, you add an endorsement often called water backup or sewer and drain backup coverage. Names and terms vary by carrier.

A backup happens when water or sewage can't flow out of your home and comes back up instead. It often shows up in a basement floor drain, a toilet or a shower on the lowest level. Common causes include:

• Heavy rain that overwhelms the municipal sewer system
• Tree roots or a blockage in your sewer line
• A sump pump that fails or loses power during a storm
• An aging or damaged pipe between your home and the main line

Policies differ, so read the wording. Water backup coverage often helps pay for:

• Cleanup and drying after the backup
• Damaged flooring, drywall and finished basement areas
• Damaged belongings, like furniture or appliances in the affected area

• The cost to repair or replace the sewer line or sump pump itself
• Flooding from surface water or rising water outside your home
• Damage from long-term leaks or poor upkeep
• Damage above the endorsement's limit

These are easy to mix up. Backup coverage is for water coming up through your plumbing. Flood insurance is for water rising from outside, like an overflowing river or storm surge, and it's a separate policy. If you live in a flood-prone area, you may want both.

Water backup endorsements usually have their own limit, which can be lower than your main coverage. Think about what's below ground level in your home. A finished basement with flooring, furniture and electronics may call for a higher limit than an unfinished one. Some states have their own rules on how carriers offer this coverage, so ask about yours.

• Don't flush wipes, grease or other items that can clog lines.
• Have your sewer line inspected if you have large trees or an older home.
• Test your sump pump and consider a battery backup.
• Ask a plumber about a backwater valve.