By Jason Allen, CBS 11 News

NORTH TEXAS (CBSDFW.COM) – After a month with 16 tornadoes in North Texas, storm shelter companies are scrambling to fill a sudden rush of orders coming in from across the country.

Some producers said they’re receiving as many as 100 calls a day from customers ready to pay any price.

In Rockwall Friday, Russell Mims had one of his family safe storm shelters on a trailer and ready for a weekend delivery.

The buyer didn’t want to wait for him to build a custom size. “They just wanted whatever I had available. They wanted it and they wanted it now.”

Mims said he gets 10 calls a day from people ready to pay cash for his shelters which start a $4,500, if he can deliver and install the steel rooms instantly.

“We’ve ramped up production, hired more welders,” he said. “We’ve called the steel suppliers and had them increase the steel supply.”

Bret West of U.S. Storm Shelters said he had received more than 15 messages Friday that he hadn’t had time to return yet.

He was too busy installing two shelters in Alvord in Wise County. He said he’s booked solid with local orders until late May.

With the sudden rush on safe rooms though, shelter builders are urging buyers to make sure they get something that will survive the biggest storms.

FEMA standards developed in 1998 call for shelters to survive 250 mile per hour wind gusts, and withstand a 2 x4 piece of wood fired at a wall at 100 miles per hour.

The National Storm Shelter Safety Association started putting seals 10 years ago on shelters that meet the most stringent standards.

“Ask your shelter producer if they’ve been tested and if they have then they should have the paperwork that says they completed the report,” said NSSSA president Tom Bennett. “Look at the report and see if they passed or failed.”

Tarrant County received a FEMA grant last year to reimburse residents or developers half the cost of a new storm shelter, up to $3,000. As of Friday though, only five people had received money.

>>Click here to find out about the grant<<

The average amount reimbursed has been about $2,200. Four more shelters are under construction and the county got permission to extend the application deadline for the money, until March 16, 2012.

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