Continuing Education 10/21/2008 WHY CHOOSE WOOD? Cost Less Lead Times Aesthetics Sustainability

Transcription

1 Continuing Education Utilization of Wood Products Michelle Kam-Biron, S.E. The Wood Products Council - WoodWorks Wood Products Council is a Registered Provider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-aia members are available on request. This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation. Registration no. 08S010. LEARNING OBJECTIVES WHY CHOOSE WOOD? 1. Increase understanding of the benefits of wood. 2. Learn about typical wood products. 3. Gain understanding of where the building codes currently allows wood frame construction to be utilized. 4. Highlights of wood use. Cost Less Lead Times Aesthetics Sustainability 1

2 Construction Materials Price Index Change in producer prices. Dec = 100 Lead Times Steel products have doubled in the past four years. Concrete products are up 35%. Wood products have declined 6%. At the same time, the consumer price index has increased 17% Steel Mill Products Lumber & Plywood Concrete Products Consumer Price Index For commonly available wood products many are in stock and ready for delivery. For special orders often lead times will be 3-5 weeks. Steel building components may have lead times at 12 weeks. Source: Bureau of Labor Statistics Wood and the Environment: Building Occupant Environment Aesthetics Wood products offer a unique aesthetic appeal. How does wood contribute to the exterior and interior environment of a building? 2

3 Wood and the Environment: Building Occupant Environment Wood makes people feel good. People are attracted to wood because of it s: Biophilia = love of living systems Visual variety, Natural irregularity, and Expressiveness Warmth, softness, and a calming effect Principles of Evidence Based Design show that occupants respond positively to wood Schools in Japan are built with wood because students respond positively Healthcare facilities in Canada have experienced the positive patient response due to humanism incorporated in the architecture of the facilities Thunder Bay Regional Health Sciences Center Salter Farrow Pilon Architects Inc., Ontario, Ca Thunder Bay Regional Health Sciences Center Salter Farrow Pilon Architects Inc. Tye Farrow, Farrow Partnership Credit Valley Hospital Mississauga, ON 3

4 Climate Change: How does wood compare? Removing CO 2 and Storing it Green Benefits of Wood Comparing CO2 emissions of different materials INCREASE Carbon Sinks DECREASE Carbon Sources Sawn lumber product s have a negative net CO2 contribution Wood industry often contributes biomass energy to the grid LCA: How does wood measure up? ATHENA OFFICE BUILDING CASE STUDY 50,000 sq. ft. Office Building Full LCA software used to compare steel, concrete and wood Climate Change: Conclusion Environmental benefits of using wood: 1. Wood products provide a means for long term carbon storage 2. Wood industry generates biomass energy which is carbon neutral 3. Wood is recyclable, renewable and reusable. 4. Wood is the only GREEN building material. 4

5 Wood Framing Members Now that we have some reasons why we should build with wood. Structural Panels Repetitive Framing Beams/ Girders Wall Studs Lets look at palette of wood framing members available. Model #A APA Form E30U Wood Framing Members Structural Panels Repetitive Framing Beams/ Girders Studs Wood Structural Panels 5

6 Plywood Layup Manufacturing Standards H860 S350 6

7 Span Rating Design Criteria APA Trademark Grade Thickness Span Rating Bond Classification Roof Span L/ PSF live 10 PSF dead Floor Span L/ PSF live 10 PSF dead Engineered Wood Construction Guide Span Rating Conditions Strength axis perpendicular to supports Continuous across 2 or more spans 7

8 Correct Panel Spacing Veneer Grade of Sheathing Panel clip or tongue-andgroove edges if required 1/8" spacing Asphalt or wood shingles or shakes. (refer to manufacturer's recommendations) APA RATED SHEATHING Protect edges of Exposure 1 panels, or use Exterior panel starter strip Stagger ends (optional) A Smooth, paintable. Not more than 18 neatly made repairs. B Solid surface. Repairs, and tight knots to 1 inch. C-Plugged Improved C veneer. Knotholes or other open defects limited to 1/4 x 1/2 inch. C Tight knots to 1-1/2 inch. Knotholes to 1 inch across grain. Occasional 1-1/2-inch knothole. D Knots and knotholes to 2-1/2 inch. Occasional 3-inch knothole. Bond Classifications APA THE ENGINEERED WOOD ASSOCIATION APA THE ENGINEERED WOOD ASSOCIATION EXTERIOR Bond Classifications EXPOSURE 1 RATED SHEATHING 32/16 15/32 INCH SIZED FOR SPACING EXTERIOR 000 PS 1-95 C-C PRP-108 RATED SHEATHING 32/16 15/32 INCH SIZED FOR SPACING EXPOSURE PS 1-95 C-D PRP-108 8

9 Exposure Durability Levels Roof Sheathing Application - HUGE Warehouses Exposure 1 Waterproof glue Permit D-grade veneer (plywood) Exterior Waterproof glue Minimum C-grade veneer (plywood) 40% of US Imports flow through California ports Ports are Bottlenecks Consolidated warehousing gaining favor 1 Million square foot warehouses are becoming common place Slide provided by John Lawson, S.E., Kramer and Lawson Panelized Roof: approx. $3.5 - $4.00/ sq.ft. GE Warehouse Ontario, CA 9

10 Pre-assemble large sections on the ground 2-3 people 4-5 minutes to assembly Lift into position with high lift capacity forklifts Fasten into place 10

11 1/8" spacing Filler strip if required APA Panel Wall Sheathing APA RATED SHEATHING Structural Insulated Panels (SIPS) 8" minimum clearance Structural Insulated Panels Structural Insulated Panels Often available in 8 x4 to 8 x24 dimensions. Benefits include; Energy efficiency Ease of Construction Limited use in high seismic areas (335plf max). APA Publication: H650 11

12 Wood Framing Members Solid Sawn Lumber - Rafters Structural Panels Repetitive Framing Beams Girders Roof Rafters Readily available 2x4 to 2x12 Spans approx. 20 In CA 32 spans are available < 16 spans are the most cost effective solution Rafters, Joist, I- Joist, Trusses Solid SawnStud Lumber Walls Floor Joist Western Wood Products Association Floor Joist Readily available 2x8 to 2x12 Spans approx. 16 In CA 32 spans available < 16 spans are the most cost effective solution Rules writing/quality Services Economic Services Lumber Grading Technical Support Information Services Product Support Services 12

13 Visual Stress-Graded Lumber Dimension Lumber evaluated by certified lumber graders Visually examine each piece Assigned grade based on visual characteristics Each grade denotes design strength and stiffness value Based on ASTM D % of lumber is visually graded. BASIC INFORMATION FROM STAMP: 1. Who made it 2. How strong is it WWPA Grade Stamps GRADE MARKS: a) WWPA Certification mark b) Mill Identification c) Grade designation d) Species identification e) Condition of seasoning MC-15 15% max. MC KD-15 S-DRY - 19% max. MC KD S-GRN - over 19% MC (unseasoned) Machine Stress-Rated Lumber (MSR) Dimension Lumber evaluated by mechanical stress rating equipment Non-destructively evaluated Bending Stiffness Sorts by Modulus of Elasticity Visual requirements MSR lower variability in strength MSR lumber properties are species independent Not widely used (limited availability) Mostly used for engineered wood or wood trusses Machine Stress-Rated Lumber (MSR) GRADE STAMP Product Designation MSR, MACHINED RATED Registered Trademark of Grading Agency Mill Number or Name Moisture Content Species Fb and E rating When additional control process are implemented Ft, SG, Fc perp and Fv 13

14 Governing Codes for Engineered Wood Design 2005 NDS (National Design Specification for Wood Construction) Solid Sawn - Availability US and Canadian Wood Species National Design Specification lists 27 commercial grades. In the Western United States Douglas Fir Larch, Hem Fir, and Spruce Pine-Fir are commonly available. Excerpt from American Wood Council s NDS Supplement Grading Rules Agency WWPA Joist and Rafter Tables OFFICE 50psf LL + 15psf LL (partition) = 65psf LL 10psf DL Western Wood Product Association als/9/docs/pdf/572.pdf 14

15 AWC Sawn Lumber Notching American Wood Council /STJR_2005.pdf BASED ON CODE REQUIREMENTS Outer third of span only Avoid tension edge WWPA Technical Note A-11 Notching and Boring Guide Solid Sawn Lumber Joist I-Joist Roof Framing Lumber Design Suite available for sawn lumber. Free Download org Floor Framing 15

16 I-Joist I-Joist I-Joist: Commonly used for floor and roof framing Long lengths readily available Flange: Lumber LVL Web: OSB Plywood Flange Widths: 1-1/2" to 3-1/2" Common Depths: 9-1/2" 11-7/8" 14" 16" Long floor spans approx. 60 Design flexibility Less material/ fewer pieces I-Joist I-Joist Holes Adaptability to skewed, curved, radiuses plans Group of holes Limit: 3 holes maximum per span 3/4x dia APA Form No. EWS D710 2x dia of larger hole 16

17 I-Joist Knockouts APA Form D710 APA Form Z725 b, a, d, g Roof Truss Configurations Pre-fabricated Roof Trusses Roof Trusses Max span approx. 75 Max scissor truss span approx

18 Roof Trusses - Rules of Thumb 2x4 chords up to a 45 span 2x6 chords up to 65 span Max. top panel length 8 for 2x4 12 for 2x6 Max. bottom chord panel length 12 for 2x4 14 for 2x6 2x3 min. web size 2x4 min. web size for all trusses spaced > 24 o.c. Max. cantilever is ¼ of the total span No girder heels less than 3.5 Truss Connectors Representative Roof Truss Tables Grade 40 Steel Characteristics: Yield Point 40,000psi Tensile Strength55,000psi Allowable Tensile Stress24,000psi Allowable Shear Stress 16,000psi Wood Truss Council of America (WTCA) dustry.com 18

19 Parallel Chord Roof and Floor Trusses Plated Floor Truss Spans OPEN WEB PLATE CONNECTED TRUSSES Spans up to 30 may be applicable for commercial construction. Floor Trusses - Rules of Thumb Representative Floor Truss Tables Maximum span to depth ratio of 20 Max. cantilever is ¼ of the total span Max. cantilever without a concentrated load at the end is 4 times the depth of the truss Max. cantilever with concentrated load at the end of the cantilever is 2 times the depth of the truss. Wood Truss Council of America (WTCA) dustry.com 19

20 OPEN WEB PIN CONNECTED TRUSS OPEN WEB PIN CONNECTED TRUSS Spans 50 floor and 120 roof Spacing 24 floor, 32 or 48 roof Depths 16 to 76 RULES OF THUMB: Deeper depths are more cost effective and allow for greater chase-way through trusses Requires 6-8 week lead times for complicated jobs and less for simple jobs More expensive than I-Joist but carries more load for longer spans. Does not work well with skewed or radius areas. Difficult to repair is field damaged. Available in custom shapes such as tapers, pitched, radiuses, etc. Wood Framing Members Solid Sawn Timber Beams Structural Panels Repetitive Framing Beams/ Girders Studs Beams Readily available 4x, 6x, or 8x and greater 24x24 up to 32 long is available Special order days lead time Spans approx. 16 (check local supplier for longer) 2 nd and 3 rd generation trees 4x lumber 5x and greater are considered Timbers 20

21 Governing Codes for Engineered Wood Design Solid Sawn Lumber Beams 2005 NDS (National Design Specification for Wood Construction) Lumber Design Suite available for sawn lumber. Free Download org Structural Composite Lumber PSL LSL LVL OSL SCL Features & Applications Structural Composite Lumber (SCL): The wood grain of veneers or strands is primarily oriented in the same direction. Strong when either face- or edge-loaded. Milled (sawn) to consistent sizes. Virtually free from warping and splitting. Strength Properties APA publishes strength properties for its members on a proprietary basis. 21

22 Laminated Veneer Lumber (LVL) LVL Plies SCL Features & Applications Laminated Veneer Lumber (LVL): Produced by bonding thin veneers together Used for beams, headers, rafters & scaffold planking The grain of all veneers is parallel to the long direction Common Thicknesses: 3/4" to 3-1/2" LVL Floor Beams LVL Used in Floor Opening 22

23 SCL Product Basics SCL Product Basics Parallel Strand Lumber (PSL): Manufactured from veneers clipped into long strands in a parallel formation and bonded together Strand length-to-thickness ratio is around 300 Used for headers and beam as well as columns. Laminated Strand Lumber (LSL): Similar to PSL. Flaked strand length-tothickness ratio is around 150 Used for a variety of applications from studs to millwork components SCL Product Basics Oriented Strand Lumber (OSL): Similar to LSL. Flaked strand length-tothickness ratio is around 75 Used for a variety of applications from studs to millwork components Glulam Glulam 23

24 Glulam: Wood laminations bonded together Wood grain runs parallel to the length Glulam Features & Applications Dispersal of Strength Reducing Characteristics Typical Widths: 2-1/2" to 10-3/4" Laminations: 1-3/8" for Southern Pine 1-1/2" for Douglas Fir 3500 Ft. r Western Stock Beam Camber 2000 Ft. r Southern Engineered Lay-ups Compression zone Zero Camber Inner zone Tension zone Critical Tension Zone 24

25 TOP Unbalanced Simple Spans No. 2D No. 2 No. 2 Glulam Manufacturing Engineered Layups Balanced Continuous Spans or Cantilevered TL No. 2 No. 2 Simple Span Unbalanced Layup Glulam Manufacturing Engineered Layups No. 3 No. 3 No. 2 No. 1 TL TL=Tension Lamination No. 2 No. 1 TL Cantilever or Continuous Span Cantilever or Continuous Span 25

26 TOP Stamp Fire Resistant Performance of Wood vs. Steel Glulam Steel 26

27 Innovation: Wood Framing Members Glulam with LVL Tension Lamination LVL Tension Lam Structural Panels Repetitive Framing Beams/ Girders Studs Full length- no finger joints Greater tensile strength = 3000 psi Glulam Floor Beams - EWS C415 Stud Walls Stud Walls For walls over 10 prescriptive tables not applicable. Engineering is required. 2x4, 3x4, 2x6 & 2x8 When wall framing exceeds 20 in height special orders may be required. Rule of thumb NDS has slenderness requirement for studs (l/d<50). For a load bearing 2x4 L < 14-7 ALWAYS Options for Tall Walls Sawn can be plained and shimmed Engineered wood Laminated strand lumber (LSL), Oriented Strand Lumber (OSL), etc. Finger Jointed Sawn Lumber 27

28 Finger Jointed Sawn Lumber Finger Jointed Sawn Lumber Sawn lumber - Approved end-jointed lumber is permitted to be used interchangeably with solid-sawn members of the same species and grade. Note HRA for 1 hr walls WWPA Portals/9/docs/PDF/F F-HRA.pdf Solid Sawn Lumber Studs Type I and II Noncombustible: Lumber Design Suite available for sawn lumber. Free Download org EXCEPT: CBC 603 Examples where FRT wood may be utilized; Non-bearing exterior walls where no fire rating is req d. Non-bearing partitions where the fire rating is 2 hours or less. In some cases roof construction including girders, trusses, framing, and decking. Heavy Timber roof framing may be utilized for rating requirements one hour or less in Type II and Type IB FIRE-RESISTANCE RATING REQUIR TYPE I BUILDING ELEMENT A B Bearing walls Exterior g 3 2 Interior 3b 2b Nonbearing walls and partitions Exterior Nonbearing walls and partitions Interior f 0 0 Floor construction Including supporting beams 2 2 Roof construction Including supporting beams 11/2 c 1 c, d Table

29 Type III Exterior Noncombustible - Interior Any Material Fire Retardant Lumber For type III construction exterior walls are assumed to be non-combustible. Floors may be combustible allowing the use of wood. FRT wood may be utilized in exterior walls required to have a fire rating of 2 hours or less. Roof may be Type IV or fire rated construction when required. Exception in California: Group A, E,F-1, H, I, L, M, R-1, R-2 and S-1. TYPE III BUILDING ELEMENT A e B Bearing walls Exterior g 2 2 Interior 1 0 Nonbearing walls and partitions Exterior Nonbearing walls and partitions Interior f 0 0 Floor construction Including supporting beams 1 0 Roof construction Including supporting beams 1 c, d 0 c, d Table 601 Available from many of the same manufacturers of preservative treatments Corrosivity Typically the same fasteners used in untreated wood may be used in fire retardant treated material see manufacturer. Fire Retardant Lumber Fire Retardant Plywood/Lumber Reduced design values for lumber. Design values and span ratings are often adjusted for FRT treatment Information available from manufacturer s or 29

30 Walls are to be non-combustible. (FRT ext. walls < 2hr.) The CBC has published minimum sizes for a structure to be Heavy Timber. Detailed provisions available from AWC and APA. Type IV Heavy Timber Type V Any Material Permitted Type V is primarily wood construction. Examples where wood may be utilized include: Rated wall and floor framing and sheathing in protected construction. Unrated walls and floors with or without sprinklers* *No allowable area increase. Unrated or one hour rated roofs. TYPE V BUILDING ELEMENT A e B Bearing walls Exterior g 1 0 Interior 1 0 Nonbearing walls and partitions Exterior Nonbearing walls and partitions Interior f 0 0 Floor construction Including supporting beams 1 0 Roof construction Including supporting beams 1 c, d 0 Table 601 Typical Rated Assemblies Exposed Wood Members DCA2 Where rated assemblies are required the CBC allows various methods for approval. Tested assemblies tested in accordance with ASTM E119 CBC Deemed to comply tables Calculated Fire Resistance (Component Additive Methodologies) Design of Fire- Resistive Exposed Wood Members Calculation of the endurance time American Wood Council 30

31 Tested Assemblies DCA3 Testing Agencies American Wood Council has accepted wood floor and wall assemblies in their free publication DCA3. American Wood Council Component Additive Method DCA4 Calculating the fire endurance of assemblies using Component Additive Method (CAM) Exposed member and time to failure of framing member American Wood Council Tested Assemblies W305 Typical Floor Assembly Attributes APA has accepted wood floor and wall assemblies in their free publication W For plated floor trusses Wood Truss Council has details available. 31

32 Sprinkler Installation APA Technical Note H730 Applications Offices Schools Assisted Living Retail Hospitality Recreation Ecclesiastic Multi-family Wood Schools VanderMolen Elementary School Corona, CA 32

33 Wood Schools Hospitality Moves to Wood 28 Open Web Wood Joist Tall Walls in Assembly Area Hotel Construction - early 1990 s Traditionally Concrete and Masonry 5-Story Wood (Type III A) Fire retardant wood exterior walls Blue Ridge Destination Center

34 Blue Ridge Destination Center Lord, Aeck & Sargent Architects, NC 1 st Sustainable Animal Shelter, Canada Winnipeg Humane Society Number Ten Architectural Group Pursuing LEED Gold /news/2007/ html LEED Gold Credit Valley Hospital and Carlo Fidani Peel Regional Cancer Centre, Mississauga ON Thunder Bay Regional Health Sciences Centre, Thunder Bay, ON Farrow Partnership Architects, Toronto, ON Salter Farrow Pilon Architects, Toronto, Ontario 640,000 (Farrow square Parnership feet Architects Inc., Salter Pilon Architects Inc., Successors 375 unit healthcare facility 34

35 Disney Ice Arena Frank O. Gehry & Assoc., Architect John A. Martin & Assoc. S.E. Disney Ice Arched Glulams 24F-V5, 8-3/4 x 50-7/8 section 75-foot radius 22 feet on center, 116 foot spans Moment splices used to allow for transportation Dining Hall & Admin. Bldg. Eleanor Roosevelt College, UCSD Moshe Safdie & Associates, Boston Architects Safdie-Rabine Architects, S.D. Nabih Youssef & Associates, Structural Engineers 35

36 Steel round cantilever columns. Approximately 3 stories high above grade 1 story below grade. Plywood over tongue and groove decking. 36

37 Great Hall 37

38 Dormitories Richmond Olympic Oval CANNON Design Gerald Epp, Fast + Epp Richmond (south of Vancouver) Richmond Olympic Oval Richmond Olympic Oval Construction began Sept Completion fall 2008 $170 million CAN 33,750 sq. metre 4 deep 2x4 Pine Lumber Renewable resource Goal to Obtain LEED Silver 38

39 Richmond Olympic Oval Richmond Olympic Oval 2010 Olympics Paralympic Winter Games Richmond Olympic Oval The Cathedral of Christ the Light Oakland, CA 39

40 Recap Recap - Applications Featured: Solid Sawn Wood Structural Panels SIPS I-Joists Trusses Engineered Beams Studs Why choose wood? Project Cost Lead Times Aesthetics Sustainability Offices Schools Assisted Living Retail Hospitality Recreation Ecclesiastic 40

41 Free Downloadable Resources American Wood Council awc.org APA The Engineered Wood apawood.org Western Wood Products Association ww2.wwpa.org WoodWorks woodworks.org Thank you!! WoodWorks! Michelle Kam-Biron, S.E