[Federal Register Volume 78, Number 13 (Friday, January 18, 2013)]
[Rules and Regulations]
[Pages 4060-4070]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-01066]
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DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT
24 CFR Part 3280
[Docket No. FR-5222-F-02]
RIN 2502-A172
Manufactured Home Construction and Safety Standards, Test
Procedures for Roof Trusses
AGENCY: Office of the Assistant Secretary for Housing--Federal Housing
Commissioner, HUD.
ACTION: Final rule.
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SUMMARY: This final rule amends the roof truss testing procedures in
the Federal Manufactured Home Construction and Safety Standards by
adopting certain recommendations made by the Manufactured Home
Consensus Committee (MHCC), as modified by HUD. Pursuant to the
National Manufactured Housing Construction and Safety Standards Act of
1974, HUD published a recommendation submitted by MHCC to revise the
existing roof truss testing procedures in 2003. In response to public
comments, HUD returned the proposal to MHCC for further evaluation.
After further consideration, MHCC submitted to HUD an amended version
of its original proposal on roof truss testing. HUD was in agreement
with the majority of MHCC's revised recommendations on roof truss
testing which were published as a proposed rule on June 16, 2010. Many
of MHCC's recommendations are included in this final rule. HUD
identifies MHCC's proposals that were not accepted, or that were
modified in light of public comments received or upon further
evaluation, and provides its reasons for not accepting or for modifying
these proposed revisions.
DATES: Effective Date: January 13, 2014.
FOR FURTHER INFORMATION CONTACT: Henry S. Czauski, Acting Deputy
Administrator, Office of Manufactured Housing Programs, Office of
Housing, Department of Housing and Urban Development, 451 7th Street
SW., Room 9164, Washington, DC 20410-8000; telephone number 202-708-
6409 (this is not a toll-free telephone number). Persons with hearing
or speech impairments may access this number through TTY by calling the
toll-free Federal Relay Service at 1-800-877-8339.
SUPPLEMENTARY INFORMATION:
I. Background
The National Manufactured Housing Construction and Safety Standards
Act of 1974 (42 U.S.C. 5401-5426) (the Act) authorizes HUD to establish
the Federal Manufactured Home Construction and Safety Standards
(Construction and Safety Standards), codified in 24 CFR part 3280. The
Act was amended by the Manufactured Housing Improvement Act of 2000
(Pub. L. 106-569), which expanded the Act's purposes and created MHCC.
Congress established MHCC to provide periodic recommendations to the
Secretary to adopt or revise provisions of the Construction and Safety
Standards.
In 2002, MHCC began considering revisions to the Construction and
Safety Standards and, in 2003, recommended revisions to the current
requirements for roof truss testing.\1\ Those recommendations were
included in HUD's proposed rule to amend the Construction and Safety
Standards, published in the Federal Register on December 1, 2004 (69 FR
70016). After considering public comment received on the proposed rule,
HUD returned the proposal on truss testing procedures to MHCC. As
indicated in the preamble of HUD's final rule published in the Federal
Register on November 30, 2005 (70 FR 72024), which followed the
December 1, 2004, proposed rule, HUD stated that truss testing
procedures are too important a safety consideration to leave
unaddressed. In returning the rule, HUD also stated that the standards
had not been modified in a number of years and needed to be examined to
determine whether they were adequate to protect homeowners in all
geographic areas of the country. HUD's review of damage assessments
following Hurricane Charley reinforced its conclusion regarding the
need for the MHCC to ensure that truss testing procedures were updated
and adequate to protect homeowners from roof and structural damage
accompanying high wind events.
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\1\ A truss is a triangular structure used to support a roof.
Multiple trusses are used to assemble the framework for a roof.
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HUD requested MHCC to work expeditiously to reevaluate and resubmit
new proposals for truss testing procedures. As a result, the Truss Test
Task Force of MHCC's Standards Subcommittee was established. Five
teleconferences of this task force were held, and the full MHCC held
two teleconferences to review and vote on new truss testing procedures.
HUD worked closely with MHCC throughout the review and reevaluation
process, and agreed with the majority of the proposals to strengthen
the truss testing procedures made by MHCC, but made editorial revisions
and modified the
[[Page 4061]]
MHCC's proposal on uplift testing. Those recommendations and
modifications were included in a proposed rule published in the Federal
Register on June 16, 2010 (75 FR 34064). After careful review of the
public comments received in response to the proposed rule, HUD made
additional editorial and other revisions and further modified the
MHCC's proposal regarding uplift testing. HUD's additional revisions in
response to public comment are reflected in this final rule.
As a result of this final rule, the required truss testing
procedures reflect the current industry standards and methods by which
trusses are tested by truss fabricators. These procedures also provide
flexibility in testing by reducing the amount of time required for the
proof load test. Most importantly, they improve the performance and
safety of trusses in high wind areas and high snow load areas, and
ultimately reduce property damage and prevent injury and loss of life
resulting from high wind events such as hurricanes and tropical storms,
as well as injuries and deaths that occur from collapsed roofs under
heavy loads. Table A identifies the changes made to the truss testing
standards as a result of this final rule.
Table A--Comparison of Roof Truss Testing Procedures
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Previous testing requirements Revised testing requirements
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Snow loads/vertical loads Snow loads/vertical loads
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Proof Load: 1.75/12 hours or Proof Load: 1.75/12 hours or 2.0/6
Ultimate Load: 2.5/5minutes. hours or Ultimate Load: 2.5/
5minutes.
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Wind Uplift Loads Wind Uplift Loads
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* Wind Zone I: 1.75/3 hours-- Wind Zone I: 2.50/1 minute--
inverted. inverted.
* Wind Zone I: 1.75/3 hours-- Wind Zone I: 1.75/1 minute--
upright. upright.
* Wind Zones II/III: 1.75/3 hours -- Wind Zones II/III: 2.0/1 minute--
inverted. inverted.
* Wind Zones II/III: 1.75/3 hours-- Wind Zones II/III: 1.75/1 minute--
upright. upright.
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* Note--The previous standards do not specify either the inverted or
upright uplift load test method. Therefore, either method was
acceptable under the existing standards and most roof truss designs
were certified using the inverted/nonconservative roof truss testing
procedure.
II. Analysis of Public Comments
The public comment period on the proposed rule closed August 16,
2010, and 12 public comments were received in response to the proposed
rule. Comments were submitted by suppliers of roof trusses,
manufactured home producers, a Design Approval Primary Inspection
Agency, and two manufactured housing trade associations. All public
comments can be found and reviewed at www.regulations.gov.
A. The Comments Generally
Comment: Generally, the commenters expressed various concerns about
HUD's proposed changes to the roof truss testing requirements. In
particular, the commenters questioned the need to requalify and retest
all existing roof truss designs based on past truss performance under
snow and wind loading. They also expressed concerns on significant cost
increases to consumers and the estimated time (18 months) needed to
requalify and retest all roof truss designs (there are approximately
1,500 existing truss designs, as estimated by a major truss supplier)
currently used by manufactured home producers that would result from
implementation of the proposed rule.
HUD Response: HUD agrees that the risk against truss failure in
snow load areas is minimal based on past performance. As a result, the
final rule limits the retesting to new truss designs in all three wind
zones, and to the estimated 150 existing truss designs used in high
wind areas (Wind Zones II and III) where the reliability and enhanced
protection is needed to mitigate against future wind damage and to
enhance wind safety in manufactured homes. HUD is also delaying
implementation for 12 months to provide manufacturers sufficient time
to retest existing trusses for Wind Zones II and III and minimize
disruption to the availability of qualifying trusses. HUD acknowledges
that wind damage to homes produced to meet its high wind standards has
been reduced in wind events that have occurred since the implementation
of the high wind requirements. However, while the damage to those homes
has been relatively minimal, questions remain about the intensity of
the windstorms and whether they were considered to be design wind
events or were at lower wind speeds than required to be resisted by the
standards.
Comment: Commenters also questioned the need to eliminate the
inverted test procedure currently being used to assess uplift
resistance of roof trusses in high wind areas. One commenter (a truss
supplier) recommended that a higher factor of safety or overload of 2.0
times the design live load should be used to conduct inverted uplift
roof truss testing and indicated that it would provide a close
approximation to the overload proposed by HUD for the upright uplift
wind test of 1.75 times the design live load.
HUD Response: HUD agrees with the commenter. As a result, the final
rule allows the use of either upright or inverted testing for Wind
Zones II or III, with a higher factor of safety of 2.0 for inverted
testing, provided additional initial tests are used to qualify the
design, and more frequent follow-up testing to verify continued truss
performance under production conditions.
Comment: Commenters questioned the cost impact of increasing the
overload factor of safety from 1.75 times the design live load for 12
hours to 2.0 times the design live load for 6 hours for the proof load
test procedure in the proposed rule.
HUD Response: HUD recognizes this issue and, in the final rule,
allows both the 2.0 overload/6 hour test and the 1.75/12 hour test to
be used for evaluating roof trusses under the proof load test
procedure.
B. Specific Issues for Comment
Question 1: Under the proposed rule, the proof load test or the
ultimate load test can be used to qualify trusses in high snow load
areas. Should the more stringent and reliable ultimate load test
procedure be required only to qualify roof trusses designed for use in
high snow load areas, such as the North and Middle Roof Load Zones,
where the risk of roof and truss failure is greater?
[[Page 4062]]
Comment: The commenters indicated that HUD should maintain the
option to use either test method in all roof load zones and that HUD
should not adopt different requirements for North and South roof load
zones because of past performance history of roof trusses in high snow
load areas.
HUD Response: HUD agrees with the commenters and has not specified
roof load zones for which the proof load or ultimate load test
procedure must be used in the final rule.
Question 2: Should the spacing between hydraulic or pneumatic
cylinders for the test fixture be increased from 12 inches to 24 inches
in Figures 3280.402(b)(1) and 3280.402(b)(3)? Should the distance
between friction pads along the top chord of the truss of the test
fixture be increased from 6 inches to 12 inches in Figure
3280.402(b)(1)? Should the distance between 1-inch straps attached
around the cylinder shoe and the top chord of the truss of the test
fixture be increased from 6 inches to 12 inches in Figure
3280.402(b)(3)?
Comment. The commenters indicated that the loading cylinders should
be maintained at 12 inches and that the loading shoes should be 6
inches long with loading pads at each end to provide a more realistic
simulation of a uniformly distributed loading upon the truss.
HUD Response: HUD agrees with the commenters that the cylinders
spacing needs to be maintained at 12 inches to more closely simulate
uniform loading of the truss, and the loading shoes need to be 6 inches
long with loading pads at each end, and has specified these
requirements in the final rule.
Question 3: Should the overload period for all wind uplift tests be
increased from 1 minute to 3 hours, as is currently required for uplift
tests in the standards for the inverted test procedure?
Comment: The commenters recommended that the 1-minute overload time
is adequate since wind pressures are based on a 3-second peak gust.
HUD Response: HUD agrees with the commenters and a 1-minute
overload time is now permitted for all uplift tests required by the
final rule.
Question 4: Should a wind uplift test always be required for
trusses qualified for use in Wind Zone I instead of allowing the
determination to be made by a Registered Engineer or Registered
Architect or independent third-party agency that is certifying the
design?
Comment: The commenters indicated that a registered design
professional will possess the necessary knowledge and experience to
decide if a wind uplift test is needed in Wind Zone I, especially since
the design load requirements are low compared to meeting the overload
requirements for vertical downward snow or gravity loading.
HUD Response: HUD agrees with the commenters that a registered
design professional has the knowledge and experience to determine if a
wind uplift test is needed for Wind Zone I, and the final rule allows
for such determinations to be made.
III. Changes to the Proposed Rule, in This Final Rule
After considering the issues raised by the commenters and HUD's own
evaluation of issues related to this final rule, HUD is making the
following specific changes to the June 16, 2010, proposed rule and
current roof truss testing requirements in Sec. 3280.402 of the
Construction and Safety Standards.
1. In Sec. 3280.402(a), upon the effective date of the rule,
testing procedures will be required for new roof truss designs in all
three wind zones and for existing truss designs used in high wind areas
(Wind Zones II and III).
2. In Sec. 3280.402(d)(1), the proof load test (formally known as
the non-destructive test procedure) contains both the proposed test
method (2.0 times the design live load for 6 hours) as well as the
existing non-destructive test method (1.75 times the design live load
for 12 hours). Three consecutive tests of truss assemblies made with
average quality materials and workmanship must meet all acceptance
criteria, including new deflection limits for dead load, in order for
the truss design to be acceptable.
3. In Sec. 3280.402(d)(2), the ultimate load test procedure (2.5
times the design live load for 5 minutes) requires that two consecutive
tests of truss assemblies made with average quality workmanship and
materials meet all acceptance criteria, including new deflection limits
for dead load, in order for the truss design to be acceptable.
4. In Sec. 3280.402(d)(3), the final rule requires that for new
truss designs to be used in Wind Zone I, when deemed necessary by a
Professional Engineer or Registered Architect, at least one truss must
meet all acceptance criteria and sustain 2.5 times the net design
uplift load (22.5) for the inverted test procedure or 1.75 times the
design uplift load (15.75) for at least 1 minute. For Wind Zone I, this
results in an increase in the factor of safety from 1.75 to 2.5 for
trusses tested for uplift in the inverted position, maintains the
current factor of safety for uplift testing at 1.75 for trusses tested
in the upright position, and reduces the period of overload testing
from 3 hours to 1 minute for both test methods. For roof trusses
designed to be used in Wind Zones II and III, both the currently
utilized inverted test method and new upright test method may be used
for conducting the wind uplift load test. However, there are different
factors of safety and the number of tests required for each test
procedure. For the inverted test method (load applied to the bottom
chord of the truss), three consecutive tests must meet all acceptance
criteria and sustain at least 2.0 times the design uplift load for 1
minute. For the upright test method (load applied to the top chord of
the truss), two consecutive tests must meet all acceptance criteria and
sustain 1.75 times the design live load for 1 minute.
5. In Sec. 3280.402(e), the follow-up testing procedures and in-
house quality control program requirements have been clarified for both
manufacturers of roof trusses and for home manufacturers producing roof
trusses for their own use. In addition, one truss test is to be
conducted after the first 100 trusses have been produced, with a
subsequent test for every 2,500 trusses qualified by either the proof
load test procedure or by the inverted test procedure. One truss test
will also be required for every 4,000 trusses produced, for trusses
qualified under the ultimate load procedure or the upright uplift test
procedure.
6. For consistency within 24 CFR part 3280, HUD is substituting
reference to a nationally recognized testing laboratory for the
reference to an independent third-party agency throughout this rule.
IV. Modifications to MHCC Recommendations
After reviewing the proposed recommendations for the revised truss
testing procedures recommended by MHCC, HUD had concerns regarding one
of MHCC's recommendations for uplift load testing. In the proposed rule
published on June 16, 2010, HUD solicited comments from the public on
both MHCC's recommendation as submitted to HUD, and HUD's modification
of its recommendation in the proposed rule, and is further modifying
MHCC's recommendation for uplift load testing.
HUD's Further Modifications to MHCC's Proposed Revision to Sec.
3280.402(d)(3)
Based on the review of comments received from the public, HUD is
further modifying the recommendation from MHCC on uplift testing,
because MHCC's overload provisions for uplift load tests in the
inverted position were deemed to be too conservative. HUD
[[Page 4063]]
now agrees with MHCC that either test method, inverted or upright,
should be permitted to evaluate uplift resistance of trusses designed
to be used in Wind Zones II and III. However, this final rule requires
that three consecutive trusses be successfully tested utilizing an
overload factor of safety of 2.0 for trusses evaluated using the
inverted test method. HUD's modification for upright testing is based
in part on the findings of a study conducted by the National
Association of Home Builders Research Center (NAHB-RC), ``Comparison of
Methods for Wind Uplift Load Testing of Roof Trusses for Manufactured
Housing,'' and the requirements of the National Fire Protection
Association (NFPA) consensus process related to uplift testing. In
particular, the NAHB-RC study found that trusses tested in the inverted
position failed at higher loads, had smaller mid-span deflections, and
experienced different fail modes than trusses tested in the upright
position. This is because the difference in truss orientation results
in the uplift load being applied by pulling up on the top chord of the
truss in the upright position (in the manner in which the wind would
apply load to the trusses), while, in the inverted position, the uplift
load is applied by pushing down on the bottom chord of the truss.
The regulatory language submitted by MHCC on this section,
including introductory language that has not been modified but which
provides context for MHCC's language, is as follows:
* * * * *
(d) * * *
(3) Uplift Load Tests. Each truss design must also pass all
requirements of the uplift load test, as applicable, in paragraph
(i) or (ii) and paragraphs (iii) and (iv) of this section.
* * * * *
(iii) Trusses designed for use in Wind Zone I, when tested [see
(i) above], must be tested in either the inverted position to 2.5
times the net wind uplift load or in the upright position to 1.75
times the net wind uplift load. Trusses designed for use in Wind
Zones II and III must be tested in the inverted position to 2.5
times the uplift load, minus the dead load, or to 1.75 times the
uplift load, minus the dead load in the upright position. [See
Figure 3280.402(b)(3)].
(iv) The following describes how to conduct the uplift test with
the truss in the upright position. Similar procedures must be used
if conducting the test in the inverted position.
* * * * *
(D) Continue to load the truss to 1.75 times the net uplift load
and maintain the full load for 1 minute. (When tested in the
inverted position, continue to load the truss to 2.5 times the net
uplift load and maintain the load for 3 hours.) See paragraph (i)
for the net uplift load in Wind Zone I and paragraph (ii) for the
uplift load for Wind Zones II and III. Regardless of the test
position of the truss, upright or inverted, trusses maintain the
overload for the specified time period without rupture, fracture, or
excessive yielding.
* * * * *
V. Findings and Certifications
Regulatory Review--Executive Orders 12866 and 13563
Under Executive Order 12866 (Regulatory Planning and Review), a
determination must be made whether a regulatory action is significant
and, therefore, subject to review by the Office of Management and
Budget (OMB) in accordance with the requirements of the order.
Executive Order 13563 (Improving Regulations and Regulatory Review)
directs executive agencies to analyze regulations that are ``outmoded,
ineffective, insufficient, or excessively burdensome, and to modify,
streamline, expand, or repeal them in accordance with what has been
learned. Executive Order 13563 also directs that, where relevant,
feasible, and consistent with regulatory objectives, and to the extent
permitted by law, agencies are to identify and consider regulatory
approaches that reduce burdens and maintain flexibility and freedom of
choice for the public.
The Office of Management and Budget (OMB) reviewed this rule under
Executive Order 12866. This rule was determined to be a ``significant
regulatory action,'' as defined in section 3(f) of the Order (although
not an economically significant regulatory action under the Order).
This rule would affect costs for manufactured home manufacturers.
As discussed in this preamble, this rule would amend the required
truss testing procedures of the Federal Manufactured Home Construction
and Safety Standards to current industry methods and equipment in order
to improve the performance and safety of trusses in high wind areas and
to enhance the reliability and durability of trusses. Specifically,
this rule would modify upright or inverted test procedures in high wind
areas in order to prevent premature failures of trusses. This rule also
would modify the current non-destructive test procedure to require a
higher factor of safety and reduces the time required to conduct the
test as well as the follow-up testing intervals. In response to public
comments, this final rule will not require retesting of existing truss
designs for manufactured housing located in Wind Zone I, which was
included in the proposed rule. The final rule will only require testing
of new roof truss designs to be used in Wind Zone I and only require
testing for uplift resistance in Wind Zone I when required by a
Professional Engineer or Registered Architect. Based on HUD's review of
this final rule, HUD has determined that this final rule imposes one-
time costs totaling $0.075 million and discounted production costs
ranging from $4.8 million, assuming a 7 percent discount rate, to $7.4
million, assuming a 3 percent discount rate. Although difficult to
predict, the discounted benefits of the rule, including prevented
damage, injury and loss of life, are expected to exceed the costs
imposed by this rule. Avoiding one death in the first year, for
example, would offset the 30-year discounted costs by 83 percent,
assuming the 3 percent discount rate, and offset the costs by 126
percent; i.e., exceed the costs, assuming the 7 percent discount rate.
If one death was avoided at the end of the 30-year period, the
discounted benefits from the prevented loss of life alone, not
including damage prevented, would account for 35 percent of the
increased costs, using a 3 percent discount rate, or 18 percent,
assuming a 7 percent discount rate. Similarly, while the number and
strength of high wind events make it difficult to provide an exact
estimate, the benefits of the rule would offset costs if 44 percent of
estimated property damage was prevented. Overall, HUD has determined
that the total impact of this rule will not exceed the $100 million
threshold as provided by Executive Order 12866.
The cost of this rule includes (1) a one-time retesting of existing
truss designs used in Wind Zones II and III, (2) redesign costs of
existing designs that do not meet the new testing requirements of this
final rule, and (3) an increase in annual production costs. These costs
are evaluated with respect to wind zone classifications. Wind Zone I
homes have the least stringent construction standards and Wind Zone III
homes have the most stringent construction standards. Approximately 90
percent of the units produced annually are constructed to Wind Zone I
standards and would not be subject to the retesting requirement.
HUD estimates that there are approximately 150 truss designs in use
for Wind Zones II and III, and that the cost of retesting,
recertifying, and redesigning the truss designs will cost producers
approximately $500 per truss design. As a result, the total cost of
retesting, re-certifying, and redesigning truss designs for Wind Zones
II and III is assessed to be $75,000 based on current production levels
of 4,620 shipments.
[[Page 4064]]
In order to meet the testing standards provided by this final rule,
HUD expects that 75 percent of the designs currently used for Wind
Zones II and III will require modification. The increased construction
cost to meet the new standards is estimated at $1.00 per truss. Based
on an average of 51 trusses per transportable section in Wind Zones II
and III, and 1.64 transportable sections per home, the annual increase
in truss construction costs total $289,170 (7,560 transportable
sections * 51 trusses per section * $1.00 increase in production cost *
75 percent of trusses produced). Over a 30-year period, the discounted
value of the increase in production costs total $4.8 million, assuming
a 7 percent discount rate, or $7.4 million, assuming a 3 percent
discount rate.
With respect to benefits, this final rule will make manufactured
housing less susceptible to wind damage and downward pressure by
enhancing roof construction. The wind damage enhancements protect
against high wind events such as hurricanes and tropical storms. Such
damage to the manufactured home ranges from complete failure of the
truss, in which the truss completely separates from the house section,
to localized failure or minor separation that leads to progressive
structural damage and damage from water entry. Complete failure of the
truss not only destroys the home itself, but in high wind events, can
result in ``missile'' damage to adjoining structures. Even minor
localized failure can over time lead to complete failure and eventually
result in ``missile'' damage in a later, perhaps weaker, wind event. In
addition, there will be less collateral damage to housing and other
structures adjacent to manufactured housing.
Quantifying the benefits of this rule, however, is difficult due to
the high annual variance in frequency and force of storms. Further,
there is virtually no detailed information concerning cost estimates of
damaged manufactured homes from strong wind or snow events. However, it
is possible to produce a reasonable, conservative estimate of property
damage that could be avoided due to the requirements in this final
rule. Due to the uncertainty of the occurrence and severity of natural
disasters, a range of expected benefits are presented. However, the
estimates below only represent a partial valuation of the expected
benefits since it is not possible to estimate the damage occurring from
heavy snow storms.
Based on 2008 housing data from the U.S. Postal Service \2\ and the
Census Bureau's Survey of Manufactured Housing, newly shipped
manufactured housing accounts for 0.076 percent of the total housing
stock in states prone to hurricane strikes. An approximation of the
damage occurring to manufactured housing totals $836,634 ($1,194,4
million * 0.076 percent). The discounted value of the annual damage
over 30 years is $11.1 million, assuming a 7 percent discount rate, or
$16.9 million, assuming a 3 percent discount rate. The higher standards
resulting from the tests required by this final rule would prevent a
portion of this damage, although the annual variability in the number
and strength of high wind events makes it difficult to provide a
precise estimate. In order for the benefits to exactly offset the costs
imposed by this rule, 44 percent of the damage would need to be
prevented This percentage should not be considered a maximum, as it
does not include damage from other types of weather events, such as
heavy snowfall, or prevented deaths, which is also discussed below.
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\2\ See http://www.huduser.org/datasets/usps.html.
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In addition to the improved safety in high wind events, the
increased reliability of trusses that result from this rule will also
benefit areas receiving high snowfall. Homes located in high snow load
areas are susceptible to collapse in heavy snow storms. The new testing
standards will decrease the number of such occurrences as new trusses
are designed. Although no data exists on the amount of property damage
due to such events, especially to manufactured housing, it is
reasonable to assume that additional benefits would accrue to owners of
manufactured housing as a result of this final rule.
In addition to avoiding property damage, this rule will also
prevent injuries and deaths that occur during hurricanes, tropical
storms, and other high wind events; although it is difficult to
estimate the number of injuries and deaths that would be prevented, it
is reasonable to expect that deaths and injuries would decrease in
response to this final rule. Government estimates of the value of a
human life range from $6.2 million used by the Department of
Transportation (DOT) to $9.1 million used by the Environmental
Protection Agency (EPA). HUD uses the DOT estimate in the current
analysis. Avoiding one death in the first year would offset the 30-year
discounted cost by 83 percent, assuming the 3 percent discount rate,
and offset the costs by 126 percent; i.e., exceed the costs, assuming
the 7 percent discount rate. If one death was avoided at the end of the
30-year period, the discounted benefits from the prevented loss of life
alone, not including damage prevented, would account for 35 percent of
the increased costs, using a 3 percent discount rate, or 18 percent
assuming a 7 percent discount rate.
In summary, this final rule will impose one-time costs totaling
$75,000, and discounted production costs ranging from $4.8 million to
$7.4 million. Although difficult to predict, the discounted benefits,
including prevented damage and prevented injury and loss of life, are
expected to exceed the costs imposed by this rule. Overall, the total
impact of this rule will not exceed the threshold of $100 million as
required by Executive Order 12866.
The docket file is available for public inspection in the
Regulations Division, Office of General Counsel, Department of Housing
and Urban Development, 451 7th Street, SW., Room 10276, Washington, DC
20410-0500. Due to security measures at the HUD Headquarters building,
please schedule an advance appointment to review the public comments by
calling the Regulations Division at 202-402-3055 (this is not a toll-
free number). Individuals with speech or hearing impairments may access
this number through TTY by calling the Federal Information Relay
Service at 1-800-877-8339.
Environmental Impact
A Finding of No Significant Impact with respect to the environment
has been made in accordance with HUD regulations at 24 CFR part 50,
which implement section 102(2)(C) of the National Environmental Policy
Act of 1969 (42 U.S.C. 4332(2)(C)). That finding is available for
public inspection between the hours of 8 a.m. and 5 p.m. weekdays in
the Regulations Division, Office of General Counsel, Department of
Housing and Urban Development, 451 7th Street, SW., Room 10276,
Washington, DC 20410-0500. Due to security measures at the HUD
Headquarters building, please schedule an appointment to review the
finding by calling the Regulations Division at 202-708-3055 (this is
not a toll-free number).
Regulatory Flexibility Act
The Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et seq.)
generally requires an agency to conduct a regulatory flexibility
analysis of any rule subject to notice and comment rulemaking
requirements, unless the agency certifies that the rule will not have a
significant economic impact on a substantial number of small entities.
This rule would regulate establishments primarily
[[Page 4065]]
engaged in making manufactured homes under North American Industry
Classification Standard (NAICS) 32991. The Small Business
Administration's size standards define as small an establishment
primarily engaged in making manufactured homes if it does not exceed
500 employees. Of the 123 manufactured home operations included under
this NAICS definition, 55 are small manufacturers that fall below the
small business threshold of 500 employees. The rule would apply to all
of the manufacturers and would, therefore, affect a substantial number
of small entities. For the reasons stated below, HUD knows of no
instance in which a manufactured home manufacturer with fewer than 500
employees would be significantly affected by this rule.
HUD, with the concurrence of MHCC, conducted an economic cost
impact analysis for this rule. A copy of the analysis is available for
public inspection and copying between 8 a.m. and 5 p.m. weekdays at the
Regulations Division, Office of General Counsel, Department of Housing
and Urban Development, 451 7th Street, SW., Room 10276, Washington, DC
20410-0500. The analysis determined the average potential cost impact,
based on a per-home cost, to be approximately $8, multiplied by an
estimated number of 46,000 homes produced in a year, which equals about
$364,000 annually. The estimated average per-home cost in Wind Zone II
and Wind Zone III is $79, based on an annual production estimate of
4,600 manufactured homes. This does not represent a significant
economic effect on either an industry-wide or per-unit basis.
These two relatively small increases in cost would not impose a
significant burden for a small business involved in the production of
homes that typically cost the purchaser between $40,000 and $100,000.
Therefore, although this rule would affect a substantial number of
small entities, it would not have a significant economic impact on
them. Accordingly, the undersigned certifies that this rule will not
have a significant economic impact on a substantial number of small
entities.
Executive Order 13132, Federalism
Executive Order 13132 (entitled ``Federalism'') prohibits an agency
from promulgating a rule that has federalism implications if the rule
either imposes substantial direct compliance costs on state and local
governments and is not required by statute, or the rule preempts state
law, unless the agency meets the consultation and funding requirements
of section 6 of the Executive Order. This rule does not have federalism
implications and does not impose substantial direct compliance costs on
state and local governments nor preempt state law within the meaning of
the Executive Order.
Unfunded Mandates Reform Act
Title II of the Unfunded Mandates Reform Act of 1995 (2 U.S.C.
1531-1538) (UMRA) establishes requirements for federal agencies to
assess the effects of their regulatory actions on state, local, and
tribal governments and on the private sector. This rule does not impose
any federal mandates on any state, local, or tribal governments or the
private sector within the meaning of UMRA.
Catalog of Federal Domestic Assistance
The Catalog of Federal Domestic Assistance number for Manufactured
Home Construction and Safety Standards is 14.171.
List of Subjects in 24 CFR Part 3280
Housing standards, Manufactured homes.
Accordingly, for the reasons stated in the preamble, HUD amends 24
CFR part 3280 to read as follows:
PART 3280--MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS
0
1. The authority citation for part 3280 continues to read as follows:
Authority: 42 U.S.C. 3535(d), 5403, and 5424.
0
2. Revise Sec. 3280.402 to read as follows:
Sec. 3280.402 Test procedures for roof trusses
(a) Roof load tests. This section provides the roof truss test
procedure for vertical loading conditions. Where roof trusses act as
support for other members, have eave or cornice projections, or support
concentrated loads, roof trusses must also be tested for those
conditions. These test procedures are required for new truss designs in
all three wind zones and for existing truss designs used in Wind Zones
II and III.
(b) General. Trusses must be tested in a truss test fixture that
replicates the design loads, and actual support points, and does not
restrain horizontal movement. When tested singly or in groups of two or
more trusses, trusses shall be mounted on supports and positioned as
intended to be installed in the manufactured home in order to give the
required clear span distance (L) and eave or cornice distance (Lo), if
applicable, as specified in the design.
(l) When trusses are tested singly, trusses shall be positioned in
a test fixture, with supports properly located and the roof loads
evenly applied. See Figure 3280.402(b)(1).
[[Page 4066]]
[GRAPHIC] [TIFF OMITTED] TR18JA13.001
(2) When tested in groups of two or more, the top chords are
permitted to be sheathed with nominal 1/4-inch x 12-inch plywood
strips. The plywood strips shall be at least long enough to cover the
top chords of the trusses at the designated design truss spacing.
Adjacent plywood strips shall be separated by at least 1/8-inch. The
plywood strips shall be nailed with 4d nails or equivalent staples no
closer than 8 inches on center along the top chord. The bottom chords
of the adjacent trusses shall be permitted to be one of the following:
(i) Unbraced; or
(ii) Laterally braced together (not cross-braced) with 1-inch x 2-
inch stripping no closer than 24 inches on center, nailed with only one
8d nail at each truss. See Figure 3280.402(b)(2).
[GRAPHIC] [TIFF OMITTED] TR18JA13.002
[[Page 4067]]
(c) Measuring and loading methods. Deflections must be measured at
the free end of an eave or cornice projection and at least at the truss
mid-span and quarter points. Scissors or other unique truss
configurations are to be measured at as many additional bottom chord
panel points as necessary to obtain an accurate representation of the
deflected shape of the truss so as to be able to locate and record the
point(s) of maximum deflection. Deflections must be read and recorded
relative to a fixed reference datum. Deflections must be read and
recorded to the nearest 1/32-inch. Dead load must be applied to the top
and bottom chord, and live load must be applied to the top chord
through a suitable hydraulic, pneumatic, or mechanical system or
weights to simulate design loads. Load unit weights for uniformly
distributed top chord loads must be separated so that arch action does
not occur and be spaced not more than 12 inches on center so as to
simulate uniform loading. Bottom chord loading must be spaced as
uniformly as practical. Truss gravity loads must be calculated based on
the overall truss length (horizontal projection), including eave or
cornice projections.
(d) Testing procedures. Either the testing method in paragraph
(d)(1) or (d)(2) of this section may be used, however, the testing
method in paragraph (d)(3) of this section must be used, to test
trusses to establish compliance with the provisions of these standards.
(1) Proof load truss test procedure. At least three average
quality/consecutively tested trusses must pass all requirements of the
test, for initial qualification of the truss design. All tests for
initial qualification of the truss designs evaluated by this procedure
must be certified by a Registered Engineer or Architect, or by a
nationally recognized testing laboratory. An in-house quality control
and follow-up testing program (see paragraphs (e) and (f) of this
section) must be approved prior to entering production of any truss
design evaluated by this procedure.
(i) Dead load. Measure and record initial elevation of the truss or
trusses in the test position at no load. Apply to the top and bottom
chords of the truss dead loads that are representative of the actual
weights of materials to be supported by the truss. However, the dead
load may only be applied as indicated in paragraph (e)(4) of this
section for ongoing follow-up testing. Dead loads to be applied to the
truss test assembly are permitted to include only the weights of
materials supported by the truss and not the weight of the truss
itself. However, readings from load cells (when used) on which the test
truss rests must reflect the sum of the applied load plus the weight of
the truss. Apply dead loads and hold for 5 minutes. Measure and record
the deflections.
(ii) Live load. Maintaining the dead loads, apply live load to the
top chord in approximate \1/4\ live load increments until dead load
plus the live load is reached. Measure and record the deflections no
sooner than one minute after each \1/4\ live load increment has been
applied and 5 minutes after the full live load has been reached.
(iii) Initial recovery phase. Remove the design live load but not
the dead load. Measure and record the deflections 5 minutes after the
total live load has been removed.
(iv) Continue to load the truss to:
(A) Dead load plus 2.0 times the design live load. Maintain this
loading for 6 hours and inspect the truss for failure. Failure is
rupture, fracture, or excessive yielding; or
(B) Dead load plus 1.75 times the design live load. Maintain this
loading for 12 hours and inspect the truss for failure. Failure is
rupture, fracture, or excessive yielding.
(v) Final recovery phase. Remove 2.0 times the design live load,
but not the dead load or 1.75 times the design live load, but not the
dead load. Measure and record deflections within 4 hours after removing
2.0 times the design live load or 1.75 times the design live load.
(vi) Acceptance criteria. The truss design is acceptable if all of
the following conditions are met:
(A) The maximum deflection between no load and dead load must be L/
480 or less for simply supported clear spans and Lo/180 or less for
eave and cornice projections; and
(B) The maximum deflection between dead load and design live load
must be L/180 or less for simply supported clear spans and Lo/90 or
less for eave and cornice projections; and
(C) After the design live load is removed, and with the dead load
still applied, the maximum recovery deflection must be L/360 or less
for simply supported spans and Lo/180 or less for eave and cornice
projections; and
(D) The truss must maintain the overload condition for 6 hours
without rupture or fracture, or excessive yielding; and
(E) After 2.0 times the design live load has been removed, and with
the dead load still applied, the maximum recovery deflection must be L/
180 or less for simply supported clear spans and Lo/90 or less for eave
and cornice projections; and
(F) As applicable, each truss design must also meet all
requirements for uplift loads required by paragraph (d)(3) of this
section. For Wind Zone I uplift load requirements, see paragraph
(d)(3)(i) of this section. For Wind Zones II and III uplift load
requirements, see paragraph (d)(3)(ii) of this section.
(2) Ultimate load truss test procedure. (i) At least two average
quality/consecutively tested trusses must pass all requirements of the
test, for initial qualification of the truss design. All tests for
initial qualification of the truss designs evaluated by this procedure
must be certified by a Registered Engineer or Architect, or by a
nationally recognized testing laboratory. An in-house quality control
and follow-up testing program (see paragraph (e) and (f) of this
section) must be approved prior to entering production of any truss
design evaluated by this procedure.
(ii) Dead load. Measure and record initial elevation of the truss
or trusses in the test position at no load. Apply to the top and bottom
chords of the truss dead loads that are representative of the actual
weights of materials to be supported by the truss. However, the dead
load may only be applied as indicated in paragraph (e)(4) of this
section for ongoing follow-up testing. Dead loads to be applied to the
truss test assembly shall be permitted to include only the weights of
materials supported by the truss, and not the weight of the truss
itself. However, readings from load cells (when used) on which the test
truss rests must reflect the sum of the applied load plus the weight of
the truss. Apply dead loads and hold for 5 minutes. Measure and record
the deflections.
(iii) Live load. Maintaining the dead loads, apply live load at a
uniform rate to the top chord in approximate \1/4\ live load increments
until the dead load plus the live load is reached. Measure and record
the deflections no sooner than one minute after each \1/4\ live load
increment has been applied and 5 minutes after the full live load has
been reached.
(iv) Initial recovery phase. Remove the design live load but not
the dead load. Measure and record the deflections 5 minutes after the
design live load has been removed.
(v) Overload phase. After the recovery phase is completed, reapply
the full live load to the truss assembly. Additional loading shall then
be applied continuously until the dead load plus 2.5 times the design
live load is reached. This overload condition must be maintained for at
least 5 minutes.
(vi) Final recovery phase. Remove 2.5 times the design live load
but not the
[[Page 4068]]
dead load. Measure and record deflections within 4 hours after 2.5
times the design live load has been removed.
(vii) Acceptance criteria. The truss design is acceptable if all of
the following conditions are met:
(A) The maximum deflection between no load and dead load must be L/
480 or less for simply supported clear spans and Lo/180 or less for
eave and cornice projections; and
(B) Dead load to design live load deflections shall be L/180 or
less for simply supported clear spans and Lo/90 or less for eave and
cornice projections; and
(C) After the design live load is removed and with the dead load
still applied, the maximum recovery deflection must be L/360 or less
for simply supported spans and Lo/180 or less for eave and cornice
projections; and
(D) The truss shall maintain the overload condition for 5 minutes
without rupture, fracture, or excessive yielding; and
(E) After 2.5 times the design live load is removed, and with the
dead load still applied, the truss must recover to at least L/180 for
simply supported clear spans and Lo/90 for eave and cornice within 4
hours after the total live load has been removed; and
(F) As applicable, each truss design must also meet all
requirements for uplift loads in Wind Zone I or Wind Zone II and III,
as required by paragraph (d)(3) of this section. For Wind Zone I uplift
load requirements, see paragraph (d)(3)(i) of this section. For Wind
Zones II and III uplift load requirements, see paragraph (d)(3)(ii) of
this section.
(3) Uplift load tests. Each truss design must also pass all
requirements of the uplift load test, as applicable, in paragraph
(d)(3)(i) or (d)(3)(ii) and paragraphs (d)(3)(iii) and (d)(3)(iv) of
this section.
(i) Wind Zone I uplift load test. Where there are engineered
connectors between the top chord and web members of the truss, such as
metal connector plates or wood gussets or their equivalents, uplift
testing in Wind Zone I is at the discretion of the Registered Engineer
or Architect or nationally recognized testing laboratory certifying the
truss design. When testing is deemed necessary by the Registered
Engineer or Architect or nationally recognized testing laboratory
certifying the truss design, a minimum of one average quality uplift
load test is to be conducted for each such truss design and must pass
all requirements of the test for initial qualification of the truss
design. The net uplift load for trusses designed for use in Wind Zone I
is 9 psf for the clear span of the truss and 22.5 psf for eave or
cornice projections.
(ii) Wind Zones II and III uplift loads test. This test is required
for all trusses designed for use in Wind Zones II and III. A minimum of
three average quality/consecutive uplift load tests are to be conducted
for each truss design when tested in the inverted position and a
minimum of two average quality/consecutive uplift load tests are to be
conducted for trusses in the upright position. The trusses must pass
all requirements of the test for initial qualification of the truss
design. The uplift load for trusses designed to be used in Wind Zones
II and III for the clear span or eave cornice projections is to be
determined by subtracting the dead load applied to the truss from the
uplift load provided in the Table of Design Wind Pressures in Sec.
3280.305(c)(1)(ii)(B).
(iii) Trusses designed for use in Wind Zone I, when tested (see
paragraph (d)(3)(i) of this section), must be tested in either the
inverted position to 2.5 times the net wind uplift load or in the
upright position to 1.75 times the net wind uplift load. Trusses
designed for use in Wind Zones II and III (see paragraph (d)(3)(ii) of
this section) must be tested to 2.0 times the uplift load minus the
dead load in the inverted position and to 1.75 times the uplift load
minus the dead load in the upright position. See Figure 3280.402(b)(3).
(iv) The following describes how to conduct the uplift test with
the truss in the upright position. Similar procedures must be used if
conducting the test in the inverted position.
(A) Place the truss in the test fixture and position as it is
intended to be installed in the manufactured home. See Figure
3280.402(b)(3).
[[Page 4069]]
[GRAPHIC] [TIFF OMITTED] TR18JA13.003
(B) Position the load measurement devices to register the wind
uplift loads that will be applied to the top chord of the truss. The
uplift loads shall be applied through tension devices not wider than
one inch and spaced not greater than approximately 12 inches on center
and shall be applied as uniform as possible, so as to simulate uniform
loading. Gravity and wind uplift load tests may be performed on the
same truss in this single setup mode. For the wind uplift test, it is
permissible to stabilize the bottom chord of the truss in the test
fixture to simulate ceiling materials or purlin supports. Measure and
record the initial elevation of the bottom chord of the truss in the
test position at the mid-span and quarter points of the truss, and at
the free end of an eave or cornice projection greater than 12 inches.
Scissors or other unique truss configurations are to be measured at as
many additional bottom chord panel points as necessary to obtain an
accurate representation of the deflected shape of the truss, so as to
be able to locate and record the point(s) of maximum deflection. Eave
or cornice projection loads are applied separately for eaves or cornice
projections greater than 12 inches. For eave or cornice projections
greater than 12 inches, the additional required load must be applied to
the eave simultaneously with the main body load. For eave or cornice
projections of 12 inches or less, add the additional required load to
the main body load and apply it to the entire top chord.
(C) Measure and record the deflection 5 minutes after the net
uplift load has been applied. Design load deflection shall be L/180 or
less for a simply supported clear span and Lo/90 or less for eave or
cornice projections.
(D) For trusses tested in the upright position, continue to load
the truss to 1.75 times the net uplift load in paragraph (d)(3)(i) of
this section for Wind Zone I and 1.75 times the uplift load in
paragraph (d)(3)(ii) for Wind Zones II and III, and maintain the load
for one minute. For trusses tested in the inverted position, continue
to load the truss to 2.50 times the net uplift load in paragraph
(d)(3)(i) for Wind Zone I and to 2.0 times the uplift load minus the
dead load in paragraph (d)(3)(ii) for Wind Zones II and III, and
maintain the full load for one minute. Regardless of the test position
of the truss, upright or inverted, trusses must maintain the overload
for the specified time period without rupture, fracture, or excessive
yielding.
(e) Follow-up testing. Follow-up testing procedures must include
the following:
(1) All trusses qualifying under these test procedures must be
subject to a quality control and follow-up testing program.
(i) Manufacturers of listed or labeled trusses must follow an in-
house quality control program with follow-up testing approved by a
nationally recognized testing program as specified in paragraph (e)(3)
of this section. The in-house quality control program must include, at
a minimum, procedures for quality of materials including, but not
limited to, grade(s) of materials, allowable splits, knots, and other
applicable lumber qualities; workmanship including, but not limited to,
plate placement and embedment tolerances; other manufacturing
tolerances; description and calibration of test equipment; truss
retesting criteria; and procedures in the event of noncomplying
results.
(ii) Those home manufacturers producing trusses for their own use,
and which are not listed or labeled, must have an in-house quality
control program (see paragraph (i) of this section) that includes
follow-up testing, as specified in this section, and is
[[Page 4070]]
approved by their Design Approval Primary Inspection Agency (DAPIA).
(2) Truss designs that are qualified but not in production are not
subject to follow-up testing until produced. When the truss design is
brought into production, a follow-up test is to be performed if the
truss design has been out of production for more than 6 months.
(3) The frequency of truss manufacturer's quality control follow-up
testing for trusses must be at least:
(i) One test for the first 100 trusses produced, with a subsequent
test for every 2,500 trusses for trusses qualified under the proof load
truss test procedure or inverted uplift test procedure for trusses used
in Wind Zones II and III or once every 6 months, whichever is more
frequent, for every truss design produced; or
(ii) One test for every 4,000 trusses produced for trusses
qualified under the ultimate load truss test procedure or upright
uplift test procedure for trusses used in Wind Zones II and III or once
every 6 months, whichever is more frequent, for every truss design
produced.
(4) For follow-up testing only, the full dead load may be applied
to the top chord of the truss, when the bottom chord dead load is 5 psf
or less.
Dated: January 8, 2013.
Carol J. Galante,
Assistant Secretary for Housing--Federal Housing Commissioner.
[FR Doc. 2013-01066 Filed 1-17-13; 8:45 am]
BILLING CODE 4210-67-P