Months after February’s freeze, many Texans are still living in damaged homes after learning too late that they had inadequate insurance.

The extreme weather that caused days of blackouts in the Lone Star State has triggered one of the costliest and most unusual insurance events in Texas history, when indoor plumbing froze and exploded in homes bereft of heat.

The damage is expected to cost insurance companies $18 billion in Texas and surrounding states, according to risk-modeling firm Karen Clark & Co., akin to the impact of a major hurricane.

Some homeowners have been left to deal with losses that their insurance doesn’t cover. Many have discovered that their policies limit payouts on plumbing-related water damage, often at $5,000 to $10,000—well below what they need.

Katherine Hensley, a 78-year-old retiree, sold her home on Tiki Island near Galveston for $575,000, far less than its prestorm appraised value of $843,000, because she had a $10,000 cap in her policy and decided that at her age, she couldn’t maintain the damaged property.