“MOBILE-HOME PARK BECOMES DEATH trap in tornado” (USA Today, 11/13/05), and “Four hurt when tornado hits mobile-home park” (Cincinnati Enquirer, 5/28/04) headlines blare. The connection between tornadoes and the destruction of manufactured homes is so commonplace in news stories that one can almost understand why a congressman would be moved to ask HUD to investigate whether tornadoes were somehow attracted to mobile-home parks (see this month's cover story, “Tumbling Dice,” page 128). Of course, that is not the case, but since half of all recent tornado-related deaths occurred in manufactured homes, the congressman can probably be forgiven for wondering.
Those deaths, some 50 to 80 each year, are not great in number, especially when compared with other causes of accidental deaths. But with sales of manufactured homes increasing, the number of fatalities is increasing as well. This is happening in spite of the strengthening of the HUD Code in 1994, mandating tougher regulations for manufactured housing in some coastal zones after the devastation delivered by Hurricane Andrew.
But those regulations did not apply to the entire middle portion of the country where the so-called Tornado Alley is found. HUD revised the code again in 1999, but the guidelines were still thought to be too general. In 2000, Congress passed the National Manufactured Housing Improvement Act, requiring each state to take over the responsibility of regulating and enforcing installation standards for manufactured homes. This law prompted a new standard providing guidance on manufactured-home installation, including site preparation, foundation design, and anchoring.
Still, even the toughest regulations and the most prescriptive guidelines won't help if they're not followed. In an investigation that followed the terrible damage done to an Evansville, Ind., mobile-home park by a tornado in November 2005, resulting in 18 deaths, engineers discovered that the spacing between anchor points far exceeded recommendations, that end straps provided by the manufacturers were almost never used by the installers, and, in one instance, no straps at all were used to fasten a unit down. Many of the homes studied were built and installed after the newer, tougher standards were in place.
The investigators also found that homes that were anchored properly (and were not hit by the vortex of the F3 tornado) withstood the ferocious storm fairly well.
From that finding, it's clear that enforcing the guidelines already in place for non-coastal construction and installation would help. Adopting the standards for coastal high-wind areas for all manufactured homes would be even better. OSB sheathing, steel connectors at floor and roof lines, and proper anchoring to a permanent foundation would make manufactured housing that much closer to site-built strong.
Strong, yes. Tornado-proof? No. Some tornadoes' wind speeds can reach upwards of 160 mph, and no home, whether mobile or site-built, can withstand gusts of that velocity. That's why disaster preparedness organizations recommend that, whenever a tornado warning occurs, site-built–home residents should go into a basement or interior room and mobile-home residents should seek other shelter. But where? Only one state (Minnesota) and a couple of municipal jurisdictions require mobile-home parks to provide storm shelters.
People of limited means who try to attain a piece of the American Dream by buying manufactured homes should be entitled to the same protections afforded those with more cash to spend. The states, already charged with the responsibility, should take a closer look at the construction and installation of the homes, provide for inspection of the finished product, and think about requiring storm shelters for some of their most vulnerable citizens.