LAMCO LFL FLOOR JOIST & RAFTER DESIGN GUIDE

Transcription

1 LAMCO LFL FLOOR JOIST & RAFTER DESIGN GUIDE

2 LAMCO-LFL GREENER EWP STRUCTURAL In any depth from 2½"-16", lengths PET d from 5-8"- 1/16" increments & available in 1¼"-1½" thickness - TRUSS / FLOOR / ROOF / WALL COMPONENTS - TALLWALL STUDS (12 to ) - STRUCTURAL RIMBOARD - JOIST (Can be Toe-Nailed = less hangers req d) DESIGN SOFTWARE: CSD - istruct. MiTek version & higher, ALPINE version & higher, WoodWorks, Keymark, and soon Simpson Strong-Tie FEATURES & BENEFITS: 100% USABLE with WANE FREE EDGES Ecessive wane & large knots removed during process. LOWER MOISTURE CONTENT <14% BETTER DIMENSIONAL STABILITY Less 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 for dimensional lumber. Made with HRA - Heat Resistant Adhesive & is a LEED certifiable product. Sold by:

3 Grade Bending, Fb (psi) Beam 6,10 Tension, Ft (psi) Compression, Fc (psi) Parallel- Parallel- Perpendicularto-Grain to-grain to-grain Design Properties Horizontal Shear, Fv (psi) Beam True 5 Modulus of Elasticity, E (10 6 psi) Modulus of Elasticity for Beam & Column Stability, Emin (10 6 psi) 1.6E E E E psi = 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 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. y L Beam y L Plank 5. Using True (shear free) E, deflection is calculated as follows for uniformly loaded simple span beams: D = [5WL 4 /(32Ebh 3 )] + [12WL 2 /(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 factor adjustment 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 values shall 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 psi for 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) , 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. Assembly Detail (See Figure 1) Connection Requirements for Side - Loaded Allowable Load for Connection of Beams Loaded from One Side Only 2 Rows of 10d 3 Rows of 10d 2 Rows of (0.148" 3") (0.148" 3") ½" Bolts Nails Nails at 12" o.c. 3,7,8 at 12" o.c. at 12" o.c. Allowable Load (per side) for Connection of Beams Loaded from Both Sides 10 2 Rows of 10d 3 Rows of 10d 2 Rows of (0.148" 3") (0.148" 3") ½" Bolts Nails Nails at 12" o.c. 3,7,8 at 12" o.c. at 12" o.c. A B C D Multiply the appropriate table value by: a. 1.5 for nails or bolts spaced at 8" o.c. per row b. 2 for nails or bolts spaced at 6" o.c. per row c. 3 for nails or bolts spaced at 4" o.c. per row d. 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 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 maimum that can be applied to each side of the beam.

4 F L O O R S P A N S Floor Joists 40 psf Live Load, 10 psf Dead Load, l/360 Deflection Floor Joists 40 psf Live Load, 15 psf Dead Load, l/360 Deflection Size Grade 12" 16" 19.2" 24" 12" 16" 19.2" 24" 1.6E E E /4" 9 1 /4" 9 1 /2" 11 1 /4" 11 7 /8" 14" 16" 2.1E E E E E E E E E E E E E E E E E E E E E E E E E SPANS The spans provided in these tables are calculated using the same as those given in the code-recognized Span Tables for Joists and Rafters and Wood Structural Design Data, both published by AF&PA. Maimum spans were computed using Allowable Stress Design (ASD) and standard engineering design formulas for simple span beams with uniformly distributed gravity loads. The calculated spans assume fully supported members, properly sheathed and nailed on the top edge of the joist. Floor applications for joists consider the effect of partial composite 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 PSI adhesive 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 building codes for specific occupancy or use categories. Spans in the tables are given in feet and inches and are the maimum allowable horizontal span of the member from inside to inside of bearings. BENDING Bending design values assume a fully supported member, properly sheathed and nailed on the top edge of the joist or rafter. The repetitive member 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. DEFLECTION Deflection may be the controlling factor in determining the member size required when appearance or rigidity is important. Control of floor vibration is another important reason to limit deflection. Deflection limits are epressed as a fraction of the span length in inches (l), and consider only live load in accordance with established engineering practice for the design of joists and rafters. COMPRESSION PERPENDICULAR-TO-GRAIN The compression perpendicular-to-grain check used to develop these span tables assumes a 2.0" bearing length to account for the end of the joist or rafter bearing on a 24 wall with a 11/2" rim board applied along the outside edge of the wall. An additional check is required for shorter 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 for determining the maimum allowable span based on horizontal shear.

5 F L O O R S P A N S Floor Joists 40 psf Live Load, 10 psf Dead Load, l/480 Deflection Floor Joists 40 psf Live Load, 15 psf Dead Load, l/480 Deflection Size Grade 12" 16" 19.2" 24" 12" 16" 19.2" 24" 7 1 /4" 9 1 /4" 9 1 /2" 11 1 /4" 11 7 /8" 14" 16" 1.6E E E E E E E E E E E E E E E E E E E E E E E E E E E E Chart based upon uniform loads stated. Joist ends shall be adequately restrained to prevent rotation. Responsibility Statement The information contained herein is a product, engineering or building code evaluation performed in accordance with the referenced building code, testing and/or analysis using generally accepted engineering practices. Product, design and code compliance quality control is the responsibility of the referenced company. Consult the referenced company for the proper detailing and application for the intended purpose. Consult your local jurisdiction or design professional to assure compliance with the local building code. Qualtim, Inc. ( and SBC Research Institute ( do not make any warranty, epress or implied, or assume any legal liability 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 and testing. SBCRI's doors are locked at all times. Qualtim staff must get clearance from Qualtim's President, Vice President or Director of R&D and Industry Projects before entering or taking any visitors into the SBCRI testing facility.

6 ROOF RAFTER SPANS Rafters 20 psf Live Load, 10 psf Dead Load, l/240 Deflection, CD = 1.15 Size Grade 12" 16" 19.2" 24" 7 1 /4" 9¼" 9 1 /2" 11 1 /4" 11 7 /8" 14" 16" 1.6E E E E E E E E E E E E E E E E E E E E E E E E Rafters 20 psf Live Load, 15 psf Dead Load, l/240 Deflection, CD = 1.15 Grade 12" 16" 19.2" 24" 1.6E E E E E E E E E E E E E E E E E E E E E E E E SUPPORT REQUIREMENTS Rafters must have adequate support. Ridge beams must be installed at roof peaks with rafters bearing directly on the ridge beam or supported by hangers or framing anchors. Ceiling joists are not required when properly designed ridge beams are used. A Ridge Board may be substituted for a ridge beam when the roof slope equals or eceeds 3 in 12, ecept that ridge beams are required for cathedral ceilings. 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 be placed directly opposite each other, and ceiling joists must be installed parallel to the rafters to provide a continuous tie between eterior walls or alternatively, standard building code approved Ridge Board and Collar-Tie framing is acceptable. SPANS The spans provided in these tables were determined on the same basis as those given in the code-recognized Span Tables for Joists and Rafters and Wood Structural Design Data, both published by AF&PA. Maimum spans were computed using Allowable Stress Design (ASD) and standard engineering design formulas for simple span beams with uniformly distributed gravity loads. The calculated spans assume fully supported members, properly sheathed and nailed on the top edge of the rafter. Rafter spans do not include composite action of adhesive and sheathing. Uplift loads caused by wind also have not been considered. Spans in the tables are given in feet and inches and are the maimum allowable horizontal span of the member from inside to inside of bearings. For sloping rafters, the span is also measured along the horizontal projection. LOAD DURATION FACTOR, CD Wood has the ability to carry substantially greater maimum loads for short durations than for long durations. For rafters, the load duration factor, CD, is typically either 1.15 for two-month snow loads or 1.25 for seven-day construction loads, or 1.6 for wind load. All rafter tables are labeled to indicate the load duration factor used. Rafter spans have been evaluated for wind loads up to and including Vasd = 110 mph (Eposure B, Mean Roof Height of 30') to determine that wind does not control design. For wind greater than Vasd = 110 mph, engineered design is required.

7 ROOF RAFTER SPANS Rafters 30 psf Live Load, 10 psf Dead Load, l/240 Deflection, CD = 1.15 Size Grade 12" 16" 19.2" 24" 7 1 /4" 9 1 /4" 9 1 /2" 11 1 /4" 11 7 /8" 14" 16" 1.6E E E E E E E E E E E E E E E E E E E E E E E E E E Rafters 30 psf Live Load, 15 psf Dead Load, l/240 Deflection, CD = 1.15 Grade 12" 16" 19.2" 24" 1.6E E E E E E E E E E E E E E E E E E E E E E E E E E Chart based upon uniform loads stated. Joist ends shall be adequately restrained to prevent rotation.

8 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 use Lamco LFL for rafters. The more we looked at the plan, the more we realized that we could use trusses for this project using relam in the bottom cord of the truss and accomplish what the customer 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 the contractor 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 on the product, and has already ordered it for headers on another job that is starting net week! Picture & Testimonial provided by Sam Yoder & Son of Delaware. LAMCO products distributed by: For more information: St-Félicien (QC) Canada Certified by: PFS Corporation Daniels Street, Madison, WI Telephone: (608) Fa: (608)