Backup sits in the gap between two covers
A supply line that bursts inside the house is covered. Rising surface water is flood and is excluded. Water that comes back up through a floor drain, a toilet or a sewer connection is a third thing, and the standard homeowners form excludes it unless a backup endorsement has been added. Households discover this category exists only when they are standing in it.
The damage is concentrated and unpleasant
Backup losses hit floors, drywall, and whatever is stored low, and they bring a contamination problem that ordinary clean water does not. The cleanup is specialist work, which is why the claims run higher than their square footage suggests.
The endorsement is cheap and limited
It is usually offered at several limit options for a modest premium. The common fault is buying the smallest option available, which can be less than a single finished room costs to restore.