NEW ORLEANS (RNS) Relief organizations whose volunteers built or repaired hundreds of damaged houses after Hurricane Katrina have found they installed toxic Chinese drywall in more than 200 buildings, requiring hundreds of low-income families to move out for months while the houses are gutted anew and rebuilt.

For many families, it’s a return to stress, dislocation and helplessness more than five years after the storm-and long after they thought their ordeal was over.

And for relief organizations, which have decided to shoulder the full cost of millions of dollars in repairs, doubling back to gut and rebuild old homes is a major budget setback that cuts into their future work.

The saga of Chinese drywall is best known to thousands of families-especially in Louisiana, Florida and Virginia-whose new or repaired homes were ruined by defective drywall introduced to the U.S. market after 2006.

In class-action suits in federal court in New Orleans, they described how sulfurous Chinese drywall emitted vapors that corroded electrical wiring; ruined the circuitry of air conditioners, appliances, computers and televisions; tarnished jewelry and other metals; pitted mirrors and sometimes made their homes stink of rotten eggs.

Habitat for Humanity, Catholic Charities’ Operation Helping Hands and Rebuilding Together New Orleans have all launched programs to identify tainted homes, move homeowners out, sustain them for months and make the houses safe for occupancy.

“We’re committed to these clients because many of them are elderly,” said Kevin Fitzpatrick of Operation Helping Hands. “They’re vulnerable. They don’t have the means or resources to make a claim, and a class-action suit could be five, six, seven years away.”

Fitzpatrick’s agency has begun testing at least 44 suspicious houses it picked out using internal records tracking Chinese drywall. Another batch of 24 or so will follow.

The largest of all the agencies, New Orleans Area Habitat for Humanity, has to redo 189 houses. It has already ripped apart and rebuilt 79, said Jim Pate, its executive director.

All of the agencies have decided to pay families’ moving costs and rent for the three to four months it typically takes to gut and rebuild a damaged house, officials said.

“For me, this is like another Katrina,” said Daniela Rivero, executive director of the group Rebuilding Together New Orleans, which has at least 19 homes with bad drywall. “We worked so hard to rebuild these houses, and now we have to rebuild them again.”

(Bruce Nolan writes for the Times-Picayune in New Orleans)