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<br /> DESIGN VALUES
<br /> Design Values for MEL, MSR, and Microttame LVL
<br /> (Values based on 2x4 nominal cross section)
<br /> MEL MSR
<br /> Properties Southern Pine Spruce-pine-fir Douglas Fir-Larch Southern Pine .Microgatn!LVL
<br /> (SP) (SKY]) (North)(DFLN) (SP)1zr truss Chord Gradi7
<br /> M-12 M-23 16501-1.5E 2100f-1.8E 1800E-1.6E 2400f-2.0E
<br /> Flexural Stress F6 = 1,600 psi 2,400 psi 1,650 psi 2,100 psi 1,800 psi 2,400 psi 2506sr i
<br /> --->.Tension Stress Fr = 850 psi 1,900 psi 1.020 psi 1,575 psi 1,175 psi 1,925 psi t 16 Nn)i psi
<br /> Compression Perpendicular to Grain Frl = 565 psi 805 psi 425 psirrl 525 psi 625 psi 805 psi 750 psi
<br /> Compression Parallel to Grain F,v = 1.675 psi 1,975 psi 1,700 psi 1,875 psi 1,750 psi 1,975 psi 2,635rrr psi
<br /> Horizontal Shear Parallel to Grain F, = 175 psi 190 psi 135 psirrr 160 psi 180 psi 190 psi121 285 psi
<br /> Modulus of Elasticity E = 1.6 x 106 psi 1.8 x 106 psi 1.5 x 106 psi 1.8 x 106 psi 1.6 x 106 psi 2.0 x 106 psi 2.0 x 106 psi
<br /> Adjusted Modulus of Elasticity E,n;, = 750,000 psi 840,000 psi 760,000 psi 910,000 psi 810,000 psi 1,020,000 psi 1,016,535 psi
<br /> (1)ft product species is stamped SP,Compression perpendicular to grain(F,1)is 565 psi and Horizontal shear parallel to grain(F,)is 175 psi.
<br /> (2)1f product species is stamped DFLN,Compression perpendicular to grain(F0)is 715 psi and Horizontal shear parallel to grain(F,)is 180 psi.
<br /> (3)For 2x4,For 2x6,F,=3,060 psi.For 2x8,F6=2.945 psi.For other depths,multiply F6=2,750 psi by[a 7 o rsb
<br /> (4)Values for 2x6 and 2x8 are the same as 2x4.
<br /> (5)F,has been adjusted for length effects in accordance with ANSVTPI.
<br /> Using Microllam•LVL in Truss Chord Applications
<br /> Only Microllame LVL that is stamped 2.0E-2750 fa or 2925 Fa and"ICC-ES ER-1387"is suitable for use in plated trusses.This special grade of
<br /> Microllam°LVL must be used in accordance with truss design software,using truss plate values supplied by the truss plate manufacturer.
<br /> Thepurchaser is solely responsible for proper design,fabrication,shipping,and for providing installation and bracing instructions for the finished truss.
<br /> APPROVED APPLICATIONS SPECIAL CONSIDERATIONS
<br /> Ua 0 General Information
<br /> Weyerhaeuser truss chord products are recommended for the following truss All truss design and fabrication should follow provisions in the National Design Standard
<br /> applications: for Metal Plate Connected hood Truss Construction.A commitment to a quality assurance
<br /> • Flat bottom chord girder and common trusses program is a must.The role of a quality assurance program is to"assure and document"
<br /> that key elements of the end product are manufactured to pre-determined minimum
<br /> •Attic trusses requirements.Weyerhaeuser recommends the quality assurance provisions in ANSI/TPI
<br /> • Tail-bearing(tray)trusses National Design Standard For Metal Plate Connected Wood Truss Construction.
<br /> • Scissor trusses There are unique aspects regarding the handling and installation of metal-plate-connected
<br /> • Parallel topand bottom chord,includingtrusses.The Structural Building Components Association's(SBCA)Building Component
<br /> girder trusses Safety Information(BCSI)summary sheets provide a wealth of information on truss issues,
<br /> • Mono-pitched trusses including:
<br /> • Trusses over 60'in length. •Best practices for truss installation
<br /> ■Long span applications
<br /> 00 NOT •Temporary bracing during construction
<br /> Weyerhaeuser truss chord products should not be used in truss applications • Fall protection
<br /> with the following highly irregular chord features: _ •Proper storage and handling
<br /> DO NOT use in trusses with bottom or top Environmental Conditions
<br /> chords that contain more than three • Microllam■LVL must be protected from the weather.Frequent or prolonged exposure to
<br /> different sloping sections. �„� % moisture or sunlight will reduce the service life of the product.
<br /> Avoid environments where steam or caustic chemicals may come in contact with the
<br /> trusses,including environments such as commercial laundries,food-processing facilities,
<br /> indoor swimming facilities,and recycling plants.
<br /> DO NOT ose in trusses with bottom or top
<br /> chords that contain a re-entrant angle c / \
<br /> greater than 45°(fillers do not count).
<br /> re-entrant wangle •
<br /> D0 NOT plate into narrow edges of
<br /> ,ice •
<br /> Microl/ame LIN as is commonly done +,� ` `
<br /> in 4x2 Oat-chord truss systems. ,,1
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<br /> Weyerhaeuser Truss Chord Specifier's Guide 9008 I June 2019 3
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