lamco lfl® floor joist & rafter design guide joists – 40 psf live load, 10 psf dead load,...

LAMCO LFL®

FLOOR JOIST & RAFTER

DESIGN GUIDE

LAMCO-LFL® GREENER EWP STRUCTURALIn any depth from 2½"-16", lengths PET’d from 5’-8"- 32’-1” @ 1/16"

increments & available in 1¼"-1½" thickness

- TRUSS / FLOOR / ROOF / WALL COMPONENTS- TALLWALL STUDS (12’ to... 32’)- STRUCTURAL RIMBOARD- JOIST (Can be Toe-Nailed = less hangers req’d)

www.LAMCOEWP.com

FEATURES & BENEFITS:● 100% USABLE with WANE FREE EDGES

Excessive wane & large knots removed during process.

● LOWER MOISTURE CONTENT <14%

● BETTER DIMENSIONAL STABILITYLess twisting, cracking and warping.

● LIGHTER than regular lumber.● STRONGER Design Values can substitute

for 1&2, MSR & LVL to 2.0E.● FLEXIBILITY for HEIGHT RESTRICTED designs.● LONGER SPANS than regular lumber.● EASY TO USE no special tools req’d.● PRE-DRILLED (available) according to

user’s specifications.● REDUCED site WASTE, LABOR & COST.● FIRE RATED ASSEMBLY LAMCO LFL® is

approved as a direct substitute fordimensional lumber. Made with HRA -Heat Resistant Adhesive & is a LEED®certifiable product.

DESIGN SOFTWARE:

CSD - iStruct®. MiTek® version 7.2.2 & higher, ALPINE® version10.01 & higher, WoodWorks®, Keymark®, and soon SimpsonStrong-Tie®

Sold by:

Grade

Bending, Fb(psi)

Tension,Ft (psi)

Compression, Fc(psi)

HorizontalShear, Fv

(psi)

Modulus ofElasticity, E

(x106psi) Modulus of Elasticity for Beam & ColumnStability, Emin (x106psi)

Beam6,10 Parallel- Parallel- Perpendicular-to-Grain to-Grain to-Grain Beam True5

1.6E 1200 13007 1600 425 135 1.6 0.793

1.7E 1800 15858 1925 595 180 1.7 0.862

1.9E 2300 18008 2190 675 205 1.9 0.968

2.1E 2300 21759 2660 675 250 2.1 1.0391. 1 psi = 0.00689 MPa or 1 MPa = 145 psi.2. The reference design values in this table are applicable for the product used in dry, well-ventilated interior applications, in which the equivalent moisture content of sawn

lumber is less than 16%. See Section 9.3.1 of this report.3. The reference design values in this table are for normal load duration. Loads of longer or shorter duration shall be adjusted in accordance with the applicable code. Duration

of load adjustments shall not be applied to Fc╨, E or Emin.4. Orientation nomenclature for Lamco LFL®.

5. Using True (shear free) E, deflection is calculated as follows for uniformly loaded simple span beams:D = [5WL4/(32Ebh3)] + [12WL2/(5Ebh)]

where: D = deflection in inches (mm)W = uniform load in lbs/in (N/mm)L = span in inches (mm)E = modulus of elasticity in psi (MPa) b= width of beam in inches (mm)h = depth of beam in inches (mm)

6. The bending values in these tables are based on a reference depth of 12" (305 mm). For other depths, the bending value for 1.6E grade shall be adjusted by a size factoradjustment of (12/d)0.34, where d is measured in inches with a minimum depth of 2.5" (64 mm). For other depths of the 1.7E, 1.9E and 2.1E grades, the bending valuesshall be adjusted by a size factor adjustment of (12/d)0.25 where d is measured in inches with a minimum depth of 2.5" (64 mm). Bending values are further limited to 2455 psifor 1.9E and 2795 psi for 2.1E grades.

7. The tension, Ft value for the 1.6E grade is based on a reference length of 24". For lengths up to 24', multiply Ft by KL . KL= (24/L)0.15, where L is the length in inches.8. The tension, Ft values for 1.7E and 1.9E grades are based on a reference length of 88" (7'4"). For lengths greater than 88", multiply Ft by KL . KL= (88/L)0.1335, where L is the

length in inches.9. The tension, Ft value for the 2.1E grade is based on a reference length of 88" (7'4"). For lengths greater than 88", multiply Ft by KL . KL= (88/L)0.125, where L is the length in

inches.10. When structural members qualify as repetitive members in accordance with the applicable code, a 4% increase is permitted to Fb.

L

y

PlankBeamxL y

x

AssemblyDetail

(See Figure 1)

Allowable Load for Connection of Beams Loaded fromOne Side Only

Allowable Load (per side) for Connection of BeamsLoaded from Both Sides10

2 Rows of 10d(0.148" x 3")

Nailsat 12" o.c.

3 Rows of 10d(0.148" x 3")

Nailsat 12" o.c.

2 Rows of½" Bolts

at 12" o.c.3,7,8

2 Rows of 10d(0.148" x 3")

Nailsat 12" o.c.

3 Rows of 10d(0.148" x 3")

Nailsat 12" o.c.

2 Rows of½" Bolts

at 12" o.c.3,7,8

A 415 625 650 210 310 325B9 310 465 485 210 310 325C – – 430 – – 325D6 – – 405 – – 325

1. Multiply the appropriate table value by:a. 1.5 for nails or bolts spaced at 8" o.c. per rowb. 2 for nails or bolts spaced at 6" o.c. per rowc. 3 for nails or bolts spaced at 4" o.c. per rowd. 0.5 for bolts spaced at 24" o.c. per row

2. Determine the appropriate beam size required to support the load before determining the connection requirements.3. Screws can be used in place of bolts, provided additional fasteners are used such that the sum of the screw capacities is equal to or greater than that of the ½"-diameter

bolts. Refer to the screw manufacturer's literature.4. Tabulated values assume adequate end distance, edge distance and spacing per Chapter 11 of NDS.5. Tabulated values are for normal load duration. Adjustment of the design stresses for duration of load shall be in accordance with the applicable code or NDS, as applicable.6. For beams greater than 4-plies wide, consult a Registered Design Professional for the attachment requirements.7. A standard cut steel washer of minimum 0.118" thickness, with a minimum outside dimension of 1⅜", is required on each side of the beam between the wood and bolt head

and nut.8. Bolted connections assume full diameter bolts with bending yield strength (Fyb) of 45,000 psi and a SG of 0.449. Nailing is required from both sides for 3-ply beams.10.The allowable loads provided above for connection of beams loaded from both sides are the maximum that can be applied to each side of the beam.

Design Properties

Connection Requirements for Side - Loaded

Floor Joists – 40 psf Live Load,10 psf Dead Load, l/360 Deflection


Size Grade 12" 16" 19.2" 24" 12" 16" 19.2" 24"

17/16"x

71/4"

1.6E 15-2 13-8 12-6 11-2 15-0 13-0 11-11 10-81.7E 15-6 14-4 13-8 12-11 15-6 14-4 13-8 12-91.9E 15-11 14-9 14-1 13-4 15-11 14-9 14-1 13-42.1E 16-3 15-1 14-4 13-7 16-3 15-1 14-4 13-7

17/16"x

91/4"

1.6E 18-11 16-9 15-3 13-8 18-5 15-11 14-7 13-01.7E 19-4 17-11 17-1 16-1 19-4 17-11 17-1 15-91.9E 20-0 18-6 17-7 16-7 20-0 18-6 17-7 16-72.1E 20-5 18-10 17-11 16-11 20-5 18-10 17-11 16-11

17/16"x

91/2"

1.6E 19-5 17-1 15-7 13-11 18-10 16-4 14-11 13-41.7E 19-10 18-4 17-6 16-6 19-10 18-4 17-6 16-21.9E 20-6 18-11 18-1 17-0 20-6 18-11 18-1 17-02.1E 20-11 19-4 18-5 17-4 20-11 19-4 18-5 17-4

17/16"x

111/4"

1.6E 22-9 19-8 17-11 16-1 21-8 18-9 17-1 15-41.7E 23-3 21-6 20-5 19-3 23-3 21-6 20-5 18-81.9E 24-1 22-2 21-1 19-10 24-1 22-2 21-1 19-102.1E 24-6 22-7 21-6 20-3 24-6 22-7 21-6 20-3

17/16"x

117/8"

1.6E 23-9 20-7 18-9 16-10 22-8 19-7 17-11 16-01.7E 24-6 22-7 21-6 20-3 24-6 22-7 21-6 19-71.9E 25-4 23-4 22-2 20-11 25-4 23-4 22-2 20-112.1E 25-10 23-10 22-7 21-3 25-10 23-10 22-7 21-3

17/16"x

14"

1.6E 27-3 23-7 21-6 19-3 26-0 22-6 20-6 18-41.7E 28-7 26-4 25-1 23-7 28-7 26-4 25-1 22-81.9E 29-7 27-3 25-11 24-4 29-7 27-3 25-11 24-42.1E 30-3 27-10 26-5 24-10 30-3 27-10 26-5 24-10

17/16"x

16"

1.6E 30-5 26-4 24-1 21-6 29-0 25-1 22-11 20-61.7E 31-8 29-11 28-5 26-8 31-8 29-11 28-5 25-51.9E 31-8 30-11 29-4 27-7 31-8 30-11 29-4 27-72.1E 31-8 31-7 29-11 28-1 31-8 31-7 29-11 28-1

SPANSThe spans provided in these tables are calculated using the same as those given in the code-recognized Span Tables for Joists and Rafters andWood Structural Design Data, both published by AF&PA. Maximum spans were computed using Allowable Stress Design (ASD) andstandard engineering design formulas for simple span beams with uniformly distributed gravity loads. The calculated spans assume fullysupported members, properly sheathed and nailed on the top edge of the joist. Floor applications for joists consider the effect of partialcomposite action with minimum of 23/32” (48/24 or 24 o.c.) glue-nailed sheathing as specified by manufacturer using 1/4” bead of 100 PSIadhesive or better meeting ASTM D 3498 applied to top of clean and dry surface of joists. If adhesive is not used: Reduce spans for 7-¼”- 9½”by 1’-0” and for 11-7/8”-16” by 1’-6”. Listed spans do not include checks for concentrated or partition loads that may be required by buildingcodes for specific occupancy or use categories. Spans in the tables are given in feet and inches and are the maximum allowable horizontal spanof the member from inside to inside of bearings.BENDINGBending design values assume a fully supported member, properly sheathed and nailed on the top edge of the joist or rafter. The repetitivemember factor, Cr, of 1.04 was included due to the assumption of the installation of at least three (3) joists or rafters spaced not more than 24"on-center. The load duration factor, CD, has also been applied as appropriate.DEFLECTIONDeflection may be the controlling factor in determining the member size required when appearance or rigidity is important. Control of floorvibration is another important reason to limit deflection. Deflection limits are expressed as a fraction of the span length in inches (l), andconsider only live load in accordance with established engineering practice for the design of joists and rafters.COMPRESSION PERPENDICULAR-TO-GRAINThe compression perpendicular-to-grain check used to develop these span tables assumes a 2.0" bearing length to account for the end of thejoist or rafter bearing on a 2x4 wall with a 11/2" rim board applied along the outside edge of the wall. An additional check is required forshorter bearing lengths, such as for 1.5" ledgers.SHEAR PARALLEL-TO-GRAIN (HORIZONTAL SHEAR)All uniformly distributed loads within a distance from the inside face of each support equal to the depth of the member have been ignored fordetermining the maximum allowable span based on horizontal shear.

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Responsibility StatementThe information contained herein is a product, engineering or building code evaluation performed inaccordance with the referenced building code, testing and/or analysis using generally acceptedengineering practices. Product, design and code compliance quality control is the responsibility ofthe referenced company. Consult the referenced company for the proper detailing and applicationfor the intended purpose. Consult your local jurisdiction or design professional to assurecompliance with the local building code. Qualtim, Inc. (www.qualtim.com) and SBC ResearchInstitute (www.sbcri.info) do not make any warranty, express or implied, or assume any legalliability or responsibility for the use, application of, and/or reference to opinions, findings,conclusions, or recommendations included in this report.

SBCRI is very careful to maintain the confidentiality of our clients' proprietary information andtesting. SBCRI's doors are locked at all times. Qualtim staff must get clearance from Qualtim'sPresident, Vice President or Director of R&D and Industry Projects before entering or taking anyvisitors into the SBCRI testing facility.



Size Grade 12" 16" 19.2" 24" 12" 16" 19.2" 24"

17/16"x

71/4"

1.6E 13-9 12-9 12-2 11-2 13-9 12-9 11-11 10-81.7E 14-1 13-0 12-5 11-9 14-1 13-0 12-5 11-91.9E 14-6 13-5 12-10 12-1 14-6 13-5 12-10 12-12.1E 14-9 13-8 13-1 12-4 14-9 13-8 13-1 12-4

17/16"x

91/4"

1.6E 17-2 15-11 15-2 13-8 17-2 15-11 14-7 13-01.7E 17-7 16-3 15-6 14-8 17-7 16-3 15-6 14-81.9E 18-2 16-10 16-0 15-1 18-2 16-10 16-0 15-12.1E 18-6 17-1 16-4 15-4 18-6 17-1 16-4 15-4

17/16"x

91/2"

1.6E 17-8 16-4 15-7 13-11 17-8 16-4 14-11 13-41.7E 18-1 16-8 15-11 15-0 18-1 16-8 15-11 15-01.9E 18-8 17-3 16-5 15-5 18-8 17-3 16-5 15-52.1E 19-0 17-7 16-8 15-9 19-0 17-7 16-8 15-9

17/16"x

111/4"

1.6E 20-8 19-1 17-11 16-1 20-8 18-9 17-1 15-41.7E 21-2 19-6 18-7 17-6 21-2 19-6 18-7 17-61.9E 21-10 20-2 19-2 18-1 21-10 20-2 19-2 18-12.1E 22-3 20-7 19-7 18-5 22-3 20-7 19-7 18-5

17/16"x

117/8"

1.6E 21-9 20-1 18-9 16-10 21-9 19-7 17-11 16-01.7E 22-3 20-6 19-6 18-5 22-3 20-6 19-6 18-51.9E 23-0 21-2 20-2 19-0 23-0 21-2 20-2 19-02.1E 23-6 21-7 20-7 19-4 23-6 21-7 20-7 19-4

17/16"x

14"

1.6E 25-5 23-5 21-6 19-3 25-5 22-6 20-6 18-41.7E 26-0 23-11 22-9 21-5 26-0 23-11 22-9 21-51.9E 26-11 24-9 23-6 22-1 26-11 24-9 23-6 22-12.1E 27-5 25-3 24-0 22-7 27-5 25-3 24-0 22-7

17/16"x

16"

1.6E 28-10 26-4 24-1 21-6 28-10 25-1 22-11 20-61.7E 29-6 27-2 25-10 24-3 29-6 27-2 25-10 24-31.9E 30-7 28-1 26-8 25-1 30-7 28-1 26-8 25-12.1E 31-2 28-8 27-2 25-7 31-2 28-8 27-2 25-7

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SChart based upon uniform loads stated. Joist ends shall be adequately restrained to prevent rotation.

Rafters – 20 psf Live Load, 10 psf Dead Load, l/240 Deflection, CD = 1.15

Size Grade 12" 16" 19.2" 24"

17/16"x

71/4"

1.6E 19-8 17-10 16-10 15-51.7E 20-3 18-4 17-3 16-11.9E 21-0 19-1 18-0 16-82.1E 21-6 19-7 18-5 17-1

17/16"x

9¼"

1.6E 25-1 22-10 21-2 18-111.7E 25-10 23-5 22-1 20-61.9E 26-10 24-4 22-11 21-32.1E 27-5 24-11 23-6 21-10

17/16"x

91/2"

1.6E 25-9 23-5 21-7 19-41.7E 26-6 24-1 22-8 21-01.9E 27-7 25-0 23-7 21-102.1E 28-2 25-7 24-1 22-5

17/16"x

111/4"

1.6E 30-6 27-3 24-10 22-31.7E 31-5 28-6 26-10 24-111.9E 31-8 29-8 27-11 25-112.1E 31-8 30-4 28-7 26-6

17/16"x

117/8"

1.6E 31-8 28-6 26-0 23-31.7E 31-8 30-1 28-4 26-31.9E 31-8 31-3 29-5 27-42.1E 31-8 31-8 30-2 28-0

17/16"x

14"

1.6E 31-8 31-8 29-10 26-81.7E 31-8 31-8 31-8 31-01.9E 31-8 31-8 31-8 31-82.1E 31-8 31-8 31-8 31-8

17/16"x

16"

1.6E 31-8 31-8 31-8 29-91.7E 31-8 31-8 31-8 31-81.9E 31-8 31-8 31-8 31-82.1E 31-8 31-8 31-8 31-8

1.6E 19-8 17-6 16-0 14-41.7E 20-3 18-4 17-3 16-11.9E 21-0 19-1 18-0 16-82.1E 21-6 19-7 18-5 17-11.6E 24-9 21-5 19-7 17-61.7E 25-10 23-5 22-1 20-61.9E 26-10 24-4 22-11 21-32.1E 27-5 24-11 23-6 21-101.6E 25-4 21-11 20-0 17-111.7E 26-6 24-1 22-8 21-01.9E 27-7 25-0 23-7 21-102.1E 28-2 25-7 24-1 22-51.6E 29-1 25-3 23-0 20-71.7E 31-5 28-6 26-10 24-111.9E 31-8 29-8 27-11 25-112.1E 31-8 30-4 28-7 26-61.6E 30-5 26-4 24-1 21-61.7E 31-8 30-1 28-4 26-31.9E 31-8 31-3 29-5 27-42.1E 31-8 31-8 30-2 28-01.6E 31-8 30-3 27-7 24-81.7E 31-8 31-8 31-8 30-51.9E 31-8 31-8 31-8 31-82.1E 31-8 31-8 31-8 31-81.6E 31-8 31-8 30-10 27-71.7E 31-8 31-8 31-8 31-81.9E 31-8 31-8 31-8 31-82.1E 31-8 31-8 31-8 31-8


Grade 12" 16" 19.2" 24"

ROOF RAFTER SPANS

SUPPORT REQUIREMENTSRafters must have adequate support. Ridge beams must be installed at roof peaks with rafters bearing directly on the ridge beam orsupported by hangers or framing anchors. Ceiling joists are not required when properly designed ridge beams are used. A Ridge Boardmay be substituted for a ridge beam when the roof slope equals or exceeds 3 in 12, except that ridge beams are required for cathedralceilings. Ridge boards must be at least 1" nominal in thickness and not less than the depth of the cut end of the rafter. Rafters must beplaced directly opposite each other, and ceiling joists must be installed parallel to the rafters to provide a continuous tie between exte-rior walls or alternatively, standard building code approved Ridge Board and Collar-Tie framing is acceptable.SPANSThe spans provided in these tables were determined on the same basis as those given in the code-recognized Span Tables for Joistsand Rafters and Wood Structural Design Data, both published by AF&PA. Maximum spans were computed using Allowable StressDesign (ASD) and standard engineering design formulas for simple span beams with uniformly distributed gravity loads. The calculat-ed spans assume fully supported members, properly sheathed and nailed on the top edge of the rafter. Rafter spans do not includecomposite action of adhesive and sheathing. Uplift loads caused by wind also have not been considered. Spans in the tables are givenin feet and inches and are the maximum allowable horizontal span of the member from inside to inside of bearings. For sloping raf-ters, the span is also measured along the horizontal projection.

LOAD DURATION FACTOR, CD – Wood has the ability to carry substantially greater maximum loads for short durations than forlong durations. For rafters, the load duration factor, CD, is typically either 1.15 for two-month snow loads or 1.25 for seven-day con-struction loads, or 1.6 for wind load. All rafter tables are labeled to indicate the load duration factor used. Rafter spans have been eval-uated for wind loads up to and including Vasd = 110 mph (Exposure B, Mean Roof Height of 30') to determine that wind does notcontrol design. For wind greater than Vasd = 110 mph, engineered design is required.


Size Grade 12" 16" 19.2" 24"

17/16"x

71/4"

1.6E 17-2 15-7 14-8 13-41.7E 17-8 16-1 15-1 14-01.9E 18-4 16-8 15-8 14-72.1E 18-10 17-1 16-1 14-11

17/16"x

91/4"

1.6E 21-11 19-11 18-4 16-41.7E 22-6 20-6 19-3 17-111.9E 23-5 21-3 20-0 18-72.1E 24-0 21-10 20-6 19-0

17/16"x

91/2"

1.6E 22-6 20-5 18-8 16-91.7E 23-2 21-0 19-9 18-41.9E 24-1 21-10 20-7 19-12.1E 24-8 22-5 21-1 19-7

17/16"x

111/4"

1.6E 26-8 23-7 21-6 19-31.7E 27-5 24-11 23-5 21-91.9E 28-6 25-11 24-4 22-72.1E 29-2 26-6 24-11 23-2

17/16"x

117/8"

1.6E 28-2 24-8 22-6 20-21.7E 28-11 26-3 24-9 23-01.9E 30-1 27-4 25-9 23-102.1E 30-10 28-0 26-4 24-5

17/16"x

14"

1.6E 31-8 28-3 25-10 23-11.7E 31-8 31-0 29-2 27-11.9E 31-8 31-8 30-4 28-22.1E 31-8 31-8 31-0 28-10

17/16"x

16"

1.6E 31-8 31-7 28-10 25-91.7E 31-8 31-8 31-8 30-111.9E 31-8 31-8 31-8 31-82.1E 31-8 31-8 31-8 31-8

1.6E 17-2 15-5 14-1 12-71.7E 17-8 16-1 15-1 14-01.9E 18-4 16-8 15-8 14-72.1E 18-10 17-1 16-1 14-111.6E 21-10 18-11 17-3 15-51.7E 22-6 20-6 19-3 17-111.9E 23-5 21-3 20-0 18-72.1E 24-0 21-10 20-6 19-01.6E 22-4 19-4 17-8 15-91.7E 23-2 21-0 19-9 18-41.9E 24-1 21-10 20-7 19-12.1E 24-8 22-5 21-1 19-71.6E 25-8 22-3 20-4 18-21.7E 27-5 24-11 23-5 21-91.9E 28-6 25-11 24-4 22-72.1E 29-2 26-6 24-11 23-21.6E 26-10 23-3 21-3 19-01.7E 28-11 26-3 24-9 23-01.9E 30-1 27-4 25-9 23-102.1E 30-10 28-0 26-4 24-51.6E 30-9 26-8 24-4 21-91.7E 31-8 31-0 29-2 26-101.9E 31-8 31-8 30-4 28-22.1E 31-8 31-8 31-0 28-101.6E 31-8 29-9 27-2 24-41.7E 31-8 31-8 31-8 30-21.9E 31-8 31-8 31-8 31-82.1E 31-8 31-8 31-8 31-8


Grade 12" 16" 19.2" 24"

ROOF RAFTER SPANS

Chart based upon uniform loads stated. Joist ends shall be adequately restrained to prevent rotation.

TALL WALLS & TRUSSES

“LAMCO LFL SOLD THE JOB “!

“A contractor came to us with plans. Originally, due to the long spans, he had planned to useLamco LFL® for rafters. The more we looked at the plan, the more we realized that we coulduse trusses for this project using relam in the bottom cord of the truss and accomplish what thecustomer wanted.

The plan called for a 32’-0” room, which cannot be designed using dimensional lumber.

It was also cost prohibitive to use LVL material. LAMCO’s 2.1E LFL® sold the job, and thecontractor is very pleased. He also ended up using the LFL® for headers on all the porches,which again, was more cost effective than using LVL’s for the beams. The contractor is sold onthe product, and has already ordered it for headers on another job that is starting next week”!

Picture & Testimonial provided by Sam Yoder & Son ofDelaware.

LAMCO products distributed by:

Certified by: PFS Corporation - 2402 Daniels Street,Madison, WI 53718 Telephone: (608) 221-3361 Fax: (608) 221-0180

For more information:

www.LamcoEWP.com

St-Félicien (QC) Canada

lamco lfl® floor joist & rafter design guide joists – 40 psf live load, 10 psf dead load,...

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