[Code of Federal Regulations]
[Title 24, Volume 5]
[Revised as of April 1, 2008]
From the U.S. Government Printing Office via GPO Access
[CITE: 24CFR3280.401]

[Page 137-138]
 
                 TITLE 24--HOUSING AND URBAN DEVELOPMENT
 
 CHAPTER XX--OFFICE OF ASSISTANT SECRETARY FOR HOUSING--FEDERAL HOUSING 
        COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT
 
PART 3280_MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS--Table of Contents
 
                            Subpart E_Testing
 
Sec. 3280.401  Structural load tests.


    Every structural assembly tested shall be capable of meeting the 
Proof Load Test or the Ultimate Load Test as follows:
    (a) Proof load tests. Every structural assembly tested must be 
capable of sustaining its dead load plus superimposed live loads equal 
to 1.75 times the required live loads for a period of 12 hours without 
failure. Tests must be conducted with loads applied and deflections 
recorded in \1/4\ design live load increments at 10-minute intervals 
until 1.25 times design live load plus dead load has been reached. 
Additional load shall then be applied continuously until 1.75 times 
design live load plus dead load has been reached. Assembly failure shall 
be considered as design live load deflection (or residual deflection 
measured 12 hours after live load removal) that is greater than the 
limits set in Sec. 3280.305(d), rupture, fracture, or excessive 
yielding. Design live load deflection criteria do not apply when the 
structural assembly being evaluated does not include structural framing 
members. An assembly to be tested shall be of the minimum quality of 
materials and workmanship of the production. Each test assembly, 
component, or subassembly shall be identified as to type and quality or 
grade of material. All assemblies, components, or subassemblies 
qualifying under this test shall be subject to a continuing 
qualification testing program acceptable to HUD.
    (b) Ultimate load tests. Ultimate load tests must be performed on a 
minimum of three assemblies or components to generally evaluate the 
structural design. Every structural assembly or component tested must be 
capable of sustaining its total dead load plus the design live load 
increased by a factor of safety of at least 2.5. A factor of safety

[[Page 138]]

greater than 2.5 shall be used when required by an applicable reference 
standard in Sec. 3280.304(b)(1). Tests shall be conducted with loads 
applied and deflections recorded in 1/4 design live load increments at 
10-minute intervals until 1.25 times design live load plus dead load has 
been reached. Additional loading shall then be applied continuously 
until failure occurs, or the total of the factor of safety times the 
design live load plus the dead load is reached. Assembly failure shall 
be considered as design live load deflection greater than the limits set 
in Sec. 3280.305(d), rupture, fracture, or excessive yielding. Design 
live load deflection criteria do not apply when the structural assembly 
being evaluated does not include structural framing members. Assemblies 
to be tested shall be representative of average quality or materials and 
workmanship of the production. Each test assembly, component, or 
subassembly shall be identified as to type and quality or grade of 
material. All assemblies, components, or subassemblies qualifying under 
this test shall be subject to a periodic qualification testing program 
acceptable to HUD.

[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, 
as amended at 58 FR 55007, Oct. 25, 1993; 70 FR 72045, Nov. 30, 2005]