Wood-Frame Construction and Engineered Wood Products an introduction Patrice Tardif Consulting 1

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1 Wood Frame Construction and Engineered Wood Products AN INTRODUCTION Architectural Structures Arch 241 Patrice R. Tardif, B. Arch. Overview Life cycle of building materials Why wood? Introduction to wood frame construction and wood products Engineered wood products, their make-up, attributes and uses Montreal, Quebec Blue Mountain Ski Resort Colllingwood, Ontario Jackson Triggs Winery Niagara-on-the-Lake, Ontario (2001) Saint-Prime-sur-le-lac Golf Club Saint-Prime, Québec (2003) Patrice Tardif Consulting 1

2 Intuit Head Office Complex Edmonton, Alberta (2002) Intuit Head Office Complex Edmonton, Alberta (2002) Ontario Department of Transportation Parc des Hautes, Sépaq Charlevoix, Québec xxx Mountain Equipment Co-op Montréal, Québec (2003) Patrice Tardif Consulting 2

3 Albert Mianscum Memorial Sports Complex Oujé-Bougoumou, Québec (2002) Gerrick s Sports Cranbrook, BC (2005) Complexe multi-sports de Laval Laval, Québec (2005) Dollarama Le Huard Mistral Industrial Building Home Hardware Chibougamau, Québec (2003) Abitibi Wood Products Manufacturing Facility (2004) Toitures Mauriciennes Truss Manufacturing Facility Trois-Rivières, Québec (2007) Other Industrial Applications Val Cartier Library Val Cartier, QC (2002) Patrice Tardif Consulting 3

4 Gene H. Kruger Pavilion, Laval University Sainte-Foy (2005) Music School Music Camp Theatre Hall Zenith Concert Hall Limoges, France (2006) Military Museum, B.C. Prince George Airport, Prince George, B. C. Brentwood Skytrain Vancouver, B.C. (2004) Patrice Tardif Consulting 4

5 Intermodal Train/Bus Station Saint-Jérôme, QC (2004) Thunder Bay Hospital Thunder Bay, Ontario (2002) Credit Valley Hospital Mississauga, Ontario (2004) Life Cycle of Building Materials Cathedral of Christ the Light Oakland, California (2008) Skidmore, Owings & Merrill An introduction to life cycle assessments (LCA) building materials from cradle to grave LCA evaluation of building materials resource extraction manufacturing requirements on-site construction occupancy / maintenance demolition recycling / reuse / disposal Certification programs examples LEED An introduction to Life Cycle Analysis An introduction to Life Cycle Analysis cont LIFE CYCLE ANALYSIS (LCA) LCA is a tool that can be used to assess the burdens placed on the environment by a product through all stages of its life. Two main aspects to LCA: Data acquisition Data analysis Cradle to Grave Patrice Tardif Consulting 5

6 LCA evaluation of building materials Data Acquisition: resource extraction manufacturing requirements on-site construction occupancy / maintenance demolition recycling / reuse / disposal Biomass Facility Recycling CO 2 Sawmill Panel Manufacturing CO 2 Extraction LCA evaluation of building materials resource extraction LCA evaluation of building materials cont LCA evaluation of building materials cont manufacturing requirements resource extraction cont LCA evaluation of building materials cont LCA evaluation of building materials cont on-site construction cont on-site construction Patrice Tardif Consulting 6

7 LCA evaluation of building materials cont LCA evaluation of building materials cont occupancy / maintenance demolition LCA evaluation of building materials cont recycling / reuse / disposal LCA evaluation of building materials cont Life cycle assessments look at environmental impacts, such as: acid rain air pollution health smog indoor air quality water intake global warming habitat alteration ecological toxicity ozone depletion fossil fuel depletion According to LCA, wood products are the most environmentally responsible construction materials when taking into consideration all of these factors. LCA evaluation of building materials cont Two main aspects to LCA: Data acquisition Data analysis Interpretation Value judgements Certification programs product standards certified forest management practices environmentally preferable products performance measurement tools Patrice Tardif Consulting 7

8 Product Standards Certified Forest Management Practices American National Standards Institute Canadian General Standards Board ISO International Organization for Standardization CSA Sustainable Forest Management Standard FSC Forest Stewardship Council SFI Sustainable Forestry Initiative Certified Forest Management Practices Environmentally Preferable Products maintenance of soil and water resources all standards offer a label for use on-product and/or on-packaging to demonstrate product links to SFM certification conservation of biological diversity Aboriginal rights and/or involvement independent audit required for certification claims sustainable harvest public disclosures Green Seal Green Cross EPP Environmentally Preferable Product Performance Measurement Tools Why wood? BREEAM TM Green Globes LEED TM GB Tool NGBS Building Research Establishment Environmental Assessment Method (Canadian and American adaptation of BREEAM) Leadership in Energy & Environmental Design Green Building Tool National Green Building Standard The certification of wood-based products is often a requirement in these programs. Hôpital Credit Valley Mississauga, ON Tye Farrow, Architecte Patrice Tardif Consulting 8

9 Why wood? Renewable and sustainable Durable Environmentally responsible (manufacturing) Reduces global greenhouse gas emissions Thermally efficient Subjective properties Why wood? renewable and sustainable Over 600 million seedlings are planted in Canada each year Renewable and sustainable Renewable and sustainable cont CANADA Sweden Russian Federation Indonesia United States New Zealand China United Kingdom 6% 40% 29% 26% 21% 16% 68% 66% 64% 63% 60% 91% 90% 86% 82% 0% 20% 40% 60% 80% 100% The rate of growth in Canada s commercial forests is equivalent to: - 50,354 houses a day - 2,098 houses an hour - 35 houses a minute Source : FAO State of the World`s Forests 2005 Renewable and sustainable cont Renewable and sustainable cont Sustainable Forest Management certification (SFM) in Canada, (millions of ha) CSA SFI 78.1 CSA FSC SFM certification in Canada and internationally, 2009 midyear (millions of ha) SFI End of year 27.5 FSC Source: Canadian Sustainable Forestry Certification Coalition July 2009 Source: Metafore's Forest Certification Resource Center, Patrice Tardif Consulting 9

10 Durable Banc de pêche de Pasbébiac Entrepot le Boutillier built in ~ 1840 Norway : Borgund stave church 12 th century Japan : Todaiji built in 752 the largest wood building in the world most recent section built in 1692 Why wood? cont Environmentally responsible renewable and sustainable durable environmentally responsible (manufacturing) Uses less energy to manufacture renewable and sustainable durable environmentally responsible (manufacturing) Uses less energy to manufacture Contributes less to air pollution AIR Energy Use (GJ x 10 8 ) Wood Steel Concrete Equivalent CO 2 (Tonnes) Wood Steel Concrete Environmentally responsible cont Environmentally responsible cont renewable and sustainable durable environmentally responsible (manufacturing) Uses less energy to manufacture Contributes less to air pollution Contributes less to water pollution WATER Index Value x 10 8 Wood Steel Concrete renewable and sustainable durable environmentally responsible (manufacturing) Uses less energy to manufacture Contributes less to air pollution Contributes less to water pollution Resource extraction requirements less onerous Index Value x 10 5 Wood Steel Concrete Patrice Tardif Consulting 10

11 Environmentally responsible cont renewable and sustainable durable environmentally responsible (manufacturing) Uses less energy to manufacture Contributes less to air and water pollution Resource extraction requirements less onerous Efficient use of raw resource 52 % dimension lumber & other wood products ; 30 % chips for pulp and paper ; 10 % bark for energy & mulch ; 8 % shavings for particleboard, MDF, energy and mulch. Why wood? cont renewable and sustainable durable environmentally responsible (manufacturing) reduces global greenhouse gas emissions Over a 20-year period a typical 216 sq. m. (2,400 sq. ft) woodframe house holds 28.5 tonnes of carbon dioxide, an amount equal to the emissions of a small car over seven years. Why wood? cont renewable and sustainable durable environmentally responsible (manufacturing) reduces global greenhouse gas emissions thermally efficient R value for wood = 1.5/in. R value for steel =.0024/in. R value for concrete =.08/ in. Thermally efficient renewable and sustainable durable environmentally responsible (manufacturing) reduces global greenhouse gas emissions thermally efficient cont Wood 2x4 Steel 2x4 2 Concrete Block 6" 1 0 Assembly R Values Why wood? cont renewable and sustainable durable environmentally responsible (manufacturing) reduces global greenhouse gas emissions thermally efficient subjective properties warmth aesthetics Why wood? cont LCA examines the entire life cycle of a product, a process or an activity... Patrice Tardif Consulting 11

12 Impact of construction on the planet: Structures are responsible for: 50% of all resources taken from nature (including 25% of the wood harvest) 50% of all total waste generated 40% of all energy consumed 40% of the world s greenhouse gas emissions - U.N. Environment Programme Impact of energy consumption by buildings: In the United States, buildings generate: 49% sulphur dioxide emissions, 25% nitrous oxide emissions, 10% particulate emissions, 35% carbon dioxide emissions. - U.S. Department of Energy Why wood? cont Embodied and Operating Energy Steel Concrete Energy Use 12% 20% Greenhouse 15% 29% Air Pollution 10% 12% Water Pollution 300% 225% Resource Use 7% 50% Solid Waste 6% 16% For a typical building with a life expectancy of 20 years. Wood and Sustainable Building Renewable sustainably Efficient use of raw resource Engineered wood products reduce waste Energy efficient Durable Less embodied energy Manufacturing is less polluting to the air and to water Reduces global greenhouse gas emissions Produced locally Good for the local economy Introduction to Wood Frame Construction and Wood Products Wood frame Construction Vertical load path: live dead snow wind seismic Lateral load path: Patrice Tardif Consulting 12

13 Architectural Structures Arch 241 Wood frame Construction cont Wood-Frame Construction Techniques: Light-frame construction Post and Beam construction Prefabricated or Manufactured construction Cross-laminated timbers Wood frame construction cont Main Structural Elements: Columns Beams Joists Secondary Structural Elements: Sheathing Decking Light-frame Construction Closely spaced members, combined with sheathing or decking, form the structural elements of the building elements used are dimension lumber sized (2 x 4 s, 2 x 6 s, etc.) 2 basic framing methods Wood frame construction cont Insulation Exterior finish Flooring Balloon framing Platform framing Gypsum wallboard Sheathing Balloon framing The wall studs are continuous for the building s height Balloon framing cont The wall studs are continuous for the building s height Floor supports are let into the wall framing members Patrice Tardif Consulting 13

14 Platform framing Platform framing cont Floor assembly built separately from walls and extends to outer edge of walls Floor assembly built separately from walls and extends to outer edge of walls Provides working surface for subsequent levels Post and Beam Construction Post and Beam Construction cont Widely-spaced sawn timbers provide structural support diagonal bracing or other support is required to resist lateral loads. Widely-spaced sawn timbers provide structural support diagonal bracing or other support is required to resist lateral loads diagonal bracing or other support is required to resist lateral loads large members connected using high capacity type connections, etc. Prefabricated or Manufactured Construction Prefabricated or Manufactured Construction cont Elements or systems are constructed off-site in controlled environments. Elements can be used in conjunction with more conventional construction techniques, or entire houses can be manufactured off-site, then transported and assembled on-site. Patrice Tardif Consulting 14

15 Prefabricated or Manufactured Construction cont Advantages: controlled environment, easier to assure quality of materials and construction techniques integrated design approach quality of the building envelope speed of assembly Cross-laminated Timbers Honeycomb structure Rotated plans Load-bearing walls, floors and cores Tallest timber building In the world Cross-laminated Timbers cont Cross-laminated Timbers cont KLH Cross-laminated Panel Cross-laminated Timbers cont nine stories in nine weeks time savings: 22 weeks Cross-laminated Timbers cont Advantages: time savings stability (shortened creep, seismic loading, ) controlled moisture content good thermal and acoustical properties less waste 3-D advantages Stability Patrice Tardif Consulting 15

16 Cross-laminated Timbers cont Wood frame construction cont Changes to the B.C. Building Code, effective January 2009: The provincial government has increased height restrictions on wood-frame residential construction from four to six stories. Main Structural Elements: Columns Beams Joists Seismic testing video: Products used for Main Stuctural Elements Main Stuctural Elements cont Dimension lumber Specialty lumber Timber Engineered wood products Dimension lumber - 4 thick (100 mm) (nominal) - visually graded and stamped as meeting standardized grading rules (NGRDL and NLGA) - Approved by the Canadian lumber standards accreditation board Main Stuctural Elements cont Main Stuctural Elements cont Dimension lumber Specialty lumber - Machine stress-rated (MSR) visually graded and mechanically tested Dimension lumber Specialty lumber - Machine stress-rated (MSR) visually graded and mechanically tested - Finger-joined lumber machined profiles end-glued Patrice Tardif Consulting 16

17 Main Stuctural Elements cont Main Stuctural Elements cont Dimension lumber Specialty lumber Timber - minimum thickness of 6 (152 mm) - visually graded and stamped as meeting NGRDL and NLGA standardized grading rules - Canadian grades and species meet CNBC requirements and CSA O86 Dimension lumber Specialty lumber Timber Engineered wood products - Structural composite lumber (SCL) - Wood I-joists - Light-frame trusses - Glulams Wood frame construction cont Products used for Secondary Stuctural Elements Secondary Structural Elements: Sheathing Decking Sheathing Decking Secondary Stuctural Elements cont Secondary Stuctural Elements cont Sheathing - Plywood - Oriented strand board (OSB) Sheathing Decking or planking - Dimension lumber with tongue and grooved profile - 3 thicknesses ranging from 1.5 ( 38 mm) to 3.5 (89 mm) Patrice Tardif Consulting 17

18 Engineered Wood Products An Engineered Wood Product (EWP) is a product that has gone through a process to provide better or more predictable properties. more design flexibility longer spans greater load carrying capacity can use the entire tree, no matter what the species, the shape or the size a good use of raw resource with less construction waste Engineered Wood Products cont Typical engineered wood products in wood-frame construction: SCL trusses glulams plywood wood I-joists OSB Plywood Plywood cont Structural panel made from thin softwood veneers (plies) in alternating cross-oriented layers that are glued together under heat and pressure using waterproof adhesives. odd # of plies that are symmetrical about the centreline sanded or unsanded tongue & grooved or square-edged must be certified to product standards and stamped as such to be accepted by building codes Plywood Attributes can be treated for added properties (resistance to fire, insects, decay) certified for exterior applications Plywood Uses floor, roof, and wall sheathing, floor underlayment, concrete formwork, box beams stressed-skin panels preserved wood foundations Oriented Strand Board (OSB) Oriented Strand Board (OSB) cont Structural panel made from successive layers of strands that are bonded together under heat and pressure with either waterproof adhesives or equivalent binders and wax. strands oriented in long direction of the panel in outer layers and typically cross-oriented in the core tongue& grooved or square-edged must be certified to product standards and stamped to be accepted by building codes OSB Attributes added strength and stiffness in the length of the panel high shear value available in many different sizes and lengths not recommended for exposed exterior applications OSB Uses floor, roof and wall sheathing structural insulated panels wood I-joist webs concrete formwork siding Patrice Tardif Consulting 18

19 Structural Composite Lumber (SCL) Structural Composite Lumber (SCL) cont Proprietary engineered wood products, each with its own design values: Parallel Strand Lumber (PSL) Laminated Veneer Lumber (LVL) Laminated Strand Lumber (LSL) glued products using exterior, waterproof resins similar structural capabilities need individual certification to be accepted in building codes manufacturers supply load tables and installation recommendations, as well as assist with layout drawings and sizing of members need engineer s approval or stamp Parallel Strand Lumber (PSL) Parallel Strand Lumber (PSL) cont PSL is an SCL that consists of strands of veneers glued together under pressure with the strands oriented along the length of the piece. beams typically available in 1-3/4 ( 44.5 mm) to 7 (178 mm) thicknesses and can be sawn to any dimension manufacturers supply load tables and installation recommendations, as well as assist with layout drawings and sizing of members ultimately need engineer s stamp PSL Attributes consistent properties resistant to seasonal stresses high load-carrying capacities suited to uses where appearance is important PSL Uses beams, columns (post & beam) beams, headers lintels (light-frame) heavy timber construction in trusses Laminated Veneer Lumber (LVL) Laminated Veneer Lumber (LVL) cont LVL is an SCL that is manufactured by curing an assembly of glued veneers together in a heated press to form billets that are subsequently cut to the depths required. grain of veneers oriented parallel to the length of the piece wider members may be built-up available up to 80 (24 m) in length LVL Attributes strong when edge loaded strong when face loaded dimensional stability high strength & reliability, low variability LVL Uses flanges for wood I-joists scaffold planking stock headers and beams columns, wall studs, in trusses Patrice Tardif Consulting 19

20 Laminated Strand Lumber (LSL) Laminated Strand Lumber (LSL) cont LSL is an SCL that is manufactured from long strands of wood, oriented parallel to each other and glued. Strands are of uniform dimension and LSL is manufactured to a consistent moisture content. LSL Attributes uniform and consistent properties transfer lateral and vertical bearing forces (rimboards) dimensionally stable LSL Uses rimboard an integral component of engineered wood systems that support wall loads and tie floor joists together studs ( m) Glued-Laminated Timber (Glulams) Glued-Laminated Timber (Glulams) cont Glulams are manufactured by gluing together dimension lumber laminations with waterproof adhesives. The lumber is first visually and mechanically graded, then sorted for strength and stiffness into lamstock grades. MC range for lamstock before assembly: 7-15% lamstock is end-joined or butted then arranged in horizontal layers and glued under pressure available in stress and appearance grades available balanced & unbalanced Stress grade defines strength of the material. Higher quality lamstock is located in high stress areas. Unbalanced beam: used for simple spans. Balanced beam: used for continuous spanning or cantilever applications. Appearance grade defines the amount of patching and finished work done to the exposed surfaces after laminating (industrial, commercial, quality). Glued-Laminated Timber (Glulams) cont Wood I-joists Glulams Attributes large members, many shapes and sizes can be curved, tapered and cambered suitable for interior or exterior use lower MC of lamstock leads to less shrinkage and checking in service Glulams Uses columns, beams, headers, girders used when structure left exposed heavy trusses Prefabricated wood I-joists are made by using exteriorrated waterproof adhesives to glue pre-dried solid sawn lumber, MSR or LVL flanges to a plywood or OSB panel web. each manufacture produces product with unique strength and stiffness characteristics using different combinations of flange and web materials with different connection details manufacturers supply allowable load and span tables need individual certification to be accepted in building codes suppliers stock standard joist hangers and other connection hardware Patrice Tardif Consulting 20

21 Wood I-joists cont Wood I-joists cont Wood I-joist Attributes dimensionally stable, lightweight with uniform stiffness and strength and known engineering properties high strength to weight ratio can be manually installed can be cut and worked using common wood working tools wide flanges allow for good fastening surface for sheathing factory pre-punched knock-out holes in web facilitate installation of electrical services Wood I-joist Uses well suited for longer span floor and roof joist applications economical alternative to open-web steel joists Trusses Light-frame Trusses Trusses use a triangular arrangement of webs and chords to transfer loads to reaction points. 2 Truss categories light-frame trusses typically prefabricated by connecting 2 (50 mm) (nominal) dimension lumber together with metal truss plates heavy-timber trusses heavy timber or EWP (glulams, PSL) connected with specialty metal connectors made from dimension lumber of various sizes chords and webs connected using toothed galvanized steel connector plates hydraulically pressed into precut lumber at joints plates must conform to specific standard requirements truss plate manufacturer typically engineers trusses on behalf of truss fabricator each proprietary product requires individual certification Light-frame Trusses cont Light-frame Trusses cont Light-frame trusses - Attributes unlimited size and shape options may be manufactured to suit any roof style Light-frame trusses Attributes cont all trusses are custom designed economical (ease of fabrication, simplified erection procedures) flexibility in layout long spanning capabilities Patrice Tardif Consulting 21

22 Light-frame Trusses cont Open-web Joists Light-frame trusses Uses residential and commercial applications Open-web joists are either metal plate connected, glued or metal-webbed trusses parallel chord trusses. generally custom designed proprietary properties and installation requirements specific loadings and other structural requirements to be clearly identified for proper design of each system Open-web Joists cont Engineered Wood Products cont Open-web joists Attributes often more economical than open-web steel joists electrical, plumbing, heating and air conditioning services may be placed between the truss chords (must be specified) can be supported on the top or bottom chord can have built-in camber permits large bay sizes with no intermediate support Open-web joists Uses floor or roof joists EWP s play an important role in wood-frame construction, both on-site and in prefabricated or manufactured systems. great design flexibility easy to handle, lead to fewer cut-offs on site, less site waste more efficient use of our forest reserves lack of defects and controlled MC of individual elements afford dimensional stability and high strength high strength to weight ratio economical, durable, lightweight alternative to solid sawn lumber Designing with Wood Designing with Wood cont The basics choose materials that are suitable for the intended application structural elements and systems used must meet the loading requirements interior or exterior use? determine spans and optimum member profiles consider material costs, including transportation to the site form and intended function of a building may dictate certain building materials Material is selected specify certified products that adhere to 3 rd party certification program verify local building code requirements insure product availability and support from manufacturer use appropriate connection detailing use appropriate building envelope detailing insure adequate site supervision Patrice Tardif Consulting 22

23 (also) Summary Life cycle assessment of building materials Appropriateness of wood as a construction material Wood-frame construction primary and secondary elements different framing options Introduction to EWPs, their uses and attributes General design considerations when designing with wood Acknowledgements Canadian Wood Council APA the Engineered Wood Association Faherty and Williamson ATHENA Institute Wood WORKS! Sustainable Forestry Initiative www Patrice Tardif Consulting 23

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