Tornado Magnets? Maybe Not, But...
Some folks still say manufactured not fallen over the last 25 years.3 have ended any such plans.
homes are “tornado magnets.” While this In 1992 Hurricane Andrew slammed In fact, the wind standards for
is unlikely, it is true that a disproportion- into Florida, destroyed over 10,000 manufactured homes in most of the
ately high number of tornado deaths occur manufactured homes in its 25 billion country (HUD’s “Wind Zone I”), including
in manufactured dollar rampage.4 Texas’ “tornado alley” and all non-coastal
(or mobile) This widespread Texas counties, are lower than model
homes. Of the destruction led to code provisions for conventional site built
348 tornado revisions of the housing for the same areas. For homes in
deaths across wind-resistance Wind Zone I, HUD recognized in 1996
the US since standards for that “the wind standards were signifi-
1998, almost half manufactured cantly below those specified for site-built
(172) occurred in homes in coastal and modular housing in moderate wind
mobile homes. and high-wind areas.”8
Site built housing prone areas. The Federal Emergency Manage-
accounted for Today, these ment Agency (FEMA) estimates the
only a third (106) Photo by Jody James improved stan- minimum HUD code standard for Wind
over that time In Happy, Texas, a tornado this year picked up a dards are cited Zone I is equivalent to about a 65 mph
mobile home and dropped it fifty feet away killing
period, although by manufacturers fastest wind speed.9 The Uniform
most people live Photo by Justin Weaver and retailers in Building Code minimum wind speed (for
in site built promotional site built homes) varies in the non-coastal
housing. Vehicles materials as areas of Texas from 70 to 90 mph.10 The
and other certification of the Castillios’ 1980 14 x 66 manufactured
locations ac- safety of manu- home was built to the basic standard
counted for the factured homes. (Wind Zone I).11
rest.1 These However, parts of Thus, while the new code provisions
statistics became the industry increase protection for hurricane prone
real here in Texas fought the coastal areas, there is little reason to
last May when standards, expect improvement in the wide swaths
Eduardo Joven unsuccessfully of middle America in HUDs “Wind Zone I”
Paper Tiger Missing Dragon, November 2002
Castillo, 37, and his wife, Yolanda Castillo, suing to block implementation in 1994. which are also prone to high winds.
35, were killed in their mobile home when The lawsuit was won by HUD, partially Meanwhile, the aging stock of
a twister struck Happy, Texas.2 on the grounds that the primary purpose existing homes are becoming even more
Manufactured home occupants die as of the HUD code was to reduce the susceptible to damage. FEMA did find
a result of tornados at 20 times the rate of injuries and deaths associated with that multi-section manufactured homes
people in of site built homes, according to manufactured housing.5 In 2000 Con- performed better in high winds, and that
a study from National Severe Storms gress revised the preface to the federal double-wide manufactured homes on
Laboratory researchers. The study ex- statute to make affordability an equal goal permanent foundations seemed to
presses concern that the growing popula- of the standards along with safety.6 HUD perform similarly to site construction.12
tion of mobile home residents will lead to a stated at the time of the 1994 changes This is promising, as multi-wide
reversal of years of decline in the national they would also consider raising wind shipments are up, and permanent
tornado death rate. More disturbingly, standards for manufactured homes in the foundations are increasingly popular. In
despite revisions of the HUD building code rest of the country as well.7 The political fact, as of this year in Texas, all new
to increase wind resistance of the struc- climate leading to the 2000 rewrite homes not in parks are required to have a
tures, the death rate from tornadoes has favoring cheap construction appears to permanent foundation system. (The
Consumers Union Southwest Regional Office
There are several theories to explain the high wind related death toll for manufactured homes. According to the industry,
tornados appear more often in the suburbs and rural areas where more manufactured homes are located. Wind experts focus
on other factors. Photographic evidence from Texas (above) points to failed tie down systems--straps break, anchors pull out,
blocks tip. A Florida survey of tie downs in existing homes found that more than 80 percent were inadequate. Texas does not
implementation of that bill may change Recommendations
the definition of “permanent,” however). ! Consumers in tornado prone
But 33 percent of new sales are still areas should consider upgrading to
single-wide units, many of which are a higher windzone home.
placed in rental communities.13 ! Consumers should get their
Orange County, Florida was galva- anchoring systems periodically
nized to action when 34 manufactured inspected.
home dwellers were killed in a single night
of tornadoes in 1998. Concerned that the
! Texas and other high wind
deaths were related to the tie-downs of prone states should develop pro-
the homes, officials began an inspection grams to assist low-income and
program offering free inspections to elderly residents inspect and replace
elderly and low-income residents. The degrading straps. Not only will this
program kicked off with 550 inspections – help protect from wind, but will help
which turned up over 450 homes with maintain these homes.
problems. These problems ranged from ! Tornado shelters should be
loose, rusty or missing steel straps to available in high density manufac-
unstable foundation piers.14 tured home areas such as parks.
This is consistent with research from
the International Hurricane Center, which
National Weather Service Storm Photo by John Taylor
found that manufactured housing anchor- Prediction Center,“Killer Tornado Wind picked up this home but left the porch.
Statistics,” 1998-2002, Internet Source:
ing capacity degrades over a period of
http://www.spc.noaa.gov/climo Manufactured Housing Program,” 1996, p. II-6
months or years. Unlike the permanent 2
Blaney, Betsy, “Residents of Texas town - II - 8.
foundations of site built housing, manu- begin cleanup after tornado kills two, injures 8
factured housing tiedowns, straps, and four,” Associated Press, 5/6/2002. 9
FEMA, “Building Performance Assess-
anchors may become loose and are 3
Brooks, Harold E and Doswell, Charles ment: Oklahoma and Kansas Tornadoes,
subject to corrosion.15 A. “A Brief History of Deaths from Tornadoes in Preliminary Report,” Chp. 7, p 6-9.
John Taylor, a citizen activist who the United States” NOAA/National Severe 10
ANSI/ASCE 7-93 UBC windspeed
advocates through the American Internet Storms Laboratory, January 2001. Internet map, Simpson Strong-Tie Co.
Society of Manufactured Home Owners source: http://www.nssl.noaa.gov/~brooks/ 11
Swisher County Apprasial District, Title
deathtrivia/ Detail and Commentary, via fax from Denise
(TAISMHO) has focused his energy on the 4
Rappaport, Ed, “Preliminary Report, Nolan, 7/8/2002.
Paper Tiger Missing Dragon, November 2002
failure of manufactured home soil auger Hurricane Andrew,” 12/10/1993 Internet 12
“Recommendations to Better Protect
anchors in high stress events. His Source: http://www.nhc.noaa.gov/ from Tornado Damage” FEMA. Internet
research has led him to conclude most 1992andrew.html; Opinion, United Circuit Source: http://www.fema.gov/hazards/
manufactured homes anchored with this Court of Appeals, 11th Circuit, No. 94-2307 tornadoes/presskit3.sht
type of anchoring system don’t meet the “Florida Manufactured Housing Assciation vs. 13
“2001 New Manufactured Homes
federal windstorm protection standards. Henry G. Cisneros. 6/12/1995. Internet Placed by Size of Home, By State,” U.S Dept.
He cites studies by both the government Source: http://www.law.emory.edu/11circuit/ of Commerce’s Census Bureau.
and industry, which Taylor says show the june95/94-2307.opa.html 14
Schultheis, Kurt D. “Anchors will help
Opinion, United Circuit Court of secure mobile homes,” The Orlando Sentinel,
current performance design loads used
Appeals, 11th Circuit, No. 94-2307 “Florida June 2, 2002.
by the manufacturers of this product are Manufactured Housing Assciation vs. Henry 15
The International Hurricane Center,
significantly higher than the actual field G. Cisneros. 6/12/1995. Internet Source: “Hurricane Loss Reduction for Residences
performance for this type of anchoring http://www.law.emory.edu/11circuit/june95/94- and Mobile Homes in Florida,” June 29, 2001.
system, despite their approval by HUD. 2307.opa.html 16
Taylor, John, email 7/18/2002. See also
He calls for elected officials to protect the 6
42 USC Sec. 5401 as of 1/16/1996; Internet Source: http://www.geocities.com/
public by ensuring proper standards are Public Law 106-569 effective 12/27/2000. taismho/
HUD, “Ninth Report to Congress on the
Consumers Union Southwest Regional Office
systematically inspect all home tie downs, and inspects no anchoring systems after initial installation. Photos by John Taylor
Harold Brooks of the National Severe Storms lab in Norman, Ok. believes manufactured homes collapse due to designs that
create weak interior walls. When one wall gives way, the whole structure can collapse. “Whereas one section of a site-built home
can be wiped out but internal framing holds the rest together,” Brooks told an Illinois reporter.