Toronto Wood Solutions Fair

Transcription

1 Canadian Wood Council G063 Building Enclosures for 5 & 6 Storey Mid-Rise Wood Buildings: Lessons Learned & Best Practices (2-hour session) Graham Finch, MASc, P. Eng. Principal, Building Science Research Specialist, RDH Building Science Inc. November 24, of 78 Credit(s) earned on completion of this course will be reported to AIA CES for AIA members. Certificates of Completion for both AIA members and non- AIA members are available upon request. This course is registered with 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. G.Finch - RDH - gfinch@rdh.com 1

2 Course Description The design and construction of wood frame building enclosures continues to evolve in response to code changes, energy efficiency requirements, past performance, new materials and many other industry factors. One of the latest evolutions has stemmed from the allowance for 5 and 6-storey wood frame buildings in parts of Canada and the US combined with the increased stringency on the thermal performance and air-tightness of building enclosures. These taller buildings face a number of challenges different from low-rise wood frame buildings built before, including increased environmental loads from wind and rain, stricter energy code requirements, and unique maintenance and operating considerations. This 2 hour seminar will cover lessons learned and many of the recent trends in materials, details and enclosure assemblies for creating durable and energyefficient mid-rise wood frame buildings. The integration of mass timber elements including cross laminated timber (CLT) and use of pre-fabrication for mid-rise and taller wood-buildings will also be covered. Learning Objectives At the end of the this course, participants will be able to: Key learning points: Participants will understand the challenges, different from low-rise wood frame buildings built before, that mid-rise wood-frame buildings face including increased environmental loads from wind and rain, stricter energy code requirements, and unique maintenance and operating considerations. Participants will benefit from lessons learned on previous mid-rise projects. Participants will learn about recent trends in materials, details and enclosure assemblies for creating durable and energy-efficient mid-rise wood frame buildings. Participants will learn about the integration of mass timber elements including cross laminated timber (CLT) and use of pre-fabrication for mid-rise and taller wood-buildings. G.Finch - RDH - gfinch@rdh.com 2

3 Building Enclosures for 5&6 Storey Mid-rise Buildings Lessons Learned & Best Practices 2015 TORONTO WOOD SOLUTIONS FAIR, NOV 24, 2015 GRAHAM FINCH, MASC, P.ENG PRINCIPAL, RDH BUILDING SCIENCE INC. Presentation Outline Background why taller wood? 5&6 storey building enclosure best practices & lessons learned Water management & claddings Air barrier strategies & materials Wood framing, energy codes & additional insulation Considerations & detailing for wood-frame shrinkage Balcony design trends Maintenance & renewals planning Reference guides & resources G.Finch - RDH - gfinch@rdh.com 3

4 Recent History of Mid-Rise Wood Buildings in Canada Pre 1900 many examples of mid-rise wood buildings up to ~10 storeys still around today Mid 1900s national building/fire codes were introduced limited wood-buildings to 3-4 storeys Mid 1990s to early 2000s, Washington & Oregon States begin to allow construction of 5 storeys wood frame over concrete podium ( 5 over 1 ) 2009 BC allows 5&6 storey wood-frame 1900s era Tall Wood Buildings Across Canada Over 250 buildings planned, under construction or built in BC to date 2013 Quebec allows 5&6 storey wood-frame 2015 Ontario allows 5&6 storey wood-frame Rest of Canada soon Wood Innovation Design Centre, BC Drivers for Larger & Taller Wood Buildings Recent industry interest, research and pilot projects to advance construction of 5&6 storey and even taller wood buildings Several Canadian efforts and initiatives Changes to building codes, allowance for alternate solutions with more wood BC Wood First Act Tall Wood Study & Tall Wood Guides (FP) Carbon sequestration (carbon sink of wood vs. carbon source for steel or concrete structures) Sustainable & Renewable Resource Aesthetics & Architectural Considerations Speed of Construction, Cost G.Finch - RDH - gfinch@rdh.com 4

5 Worldwide Tall Mass Timber Buildings 8 storeys LCT One, Austria, Hermann Kaufmann 9 storeys Melbourne Australia, Land Lease 8 storeys Finland, OOPEAA 14 storeys, Treet Norway, Artec 9 storeys Murray Grove, UK, Waugh Thistleton Architects Many Similarities: - Mass Timber Components, CLT, Glulams etc. - Pre-fabricated components (walls, floor panels) - Hybrid wood & concrete structures Emerging Trends - Taller Wood in North America 12 storey wood, Portland OR (in design) ~100ft wood, Prince George, BC Wood Innovation Design Centre 18 storey wood, Vancouver, BC 10 storey wood, New York (in design) G.Finch - RDH - gfinch@rdh.com 5

6 5&6 Storey Mid-rise Wood-frame Building Enclosures for 5&6 Storey What is Different? Taller buildings = increased exposure to wind and rain Need for better site protection, use of more robust assemblies and materials including roofing, claddings & windows, consideration of pre-fab More structural framing Less space for insulation within studs Unique wood/steel/concrete interfaces and details to consider Non-combustible claddings & enhanced fire-safety considerations during construction & in-service Different energy code requirements than 3&4 storey & Part 9 wood-frame G.Finch - RDH - gfinch@rdh.com 6

7 Building Enclosures for 5&6 Storey Trends More than decade of experience with 5&6 storey wood-frame buildings on the west coast (BC, WA, OR) Continuous progression of building enclosure practices resulting from: Building code changes including WA State requirements for whole building air-tightness testing Energy code changes pushing wall R-values beyond 2x6 studs w/ batt insulation Pre-fabrication of walls, balconies and other components to speed-up construction Unique details to accommodate or minimize the impacts of wood shrinkage Reconsidered material, assembly, & detailing choices appropriate for increased exposure G.Finch - RDH - gfinch@rdh.com 7

8 And When It Isn t Challenging Enough on Land G.Finch - RDH - gfinch@rdh.com 8

9 Building Enclosure Design Fundamentals Separates indoors from outdoors, by controlling: Water penetration Condensation Air flow Vapor diffusion (wetting & drying) Heat flow Light and solar radiation Noise, fire, and smoke While at the same time: Transferring structural loads Being durable and maintainable Being economical & constructible Looking good! Building Enclosure Control Functions & Critical Barriers G.Finch - RDH - gfinch@rdh.com 9

10 Water Control 5&6 Storey Wood-frame Increased height = increased rain deposition at upper floors and cumulative run-down at lower levels Water shedding features become more critical continuity, drip edges, flashings etc. Increased exposure to moisture during construction (severity & length of time) Need for more robust water penetration control strategy good practice: drained & ventilated rainscreen Keep Wood Dry During Construction Keep wood drying during construction Have seen issues in west where wood assemblies have got too wet during construction and resulted in delays & significant costs to dry out Hence guidance for protection during construction, temporary roofs, immediate roofing, windows, wall/roof water resistive barrier (WRB) preapplication, built-in assembly design & redundancy for drying G.Finch - RDH - gfinch@rdh.com 10

11 Protect Wood from Water But Not too Late Ensure adequate rainwater protection for heavy mass timber elements such as CLT, nail-lam, LVL/LSL/PSL, glulams etc. and multi layer plywood assemblies especially for horizontal surfaces Either choose preapplication of waterproof elements or invest in good site protection Construction Practices for Mid-rise Wood Frame Many contractors in west will either intentionally (or unintentionally) invest in site protection so that roofing/waterproofing can be applied in inclement weather onto dry materials Typically observe that walls are seldom covered with a WRB until top floor framing is complete However window sills & rough openings generally covered right away allow for immediate window install & site close-in as fast as possible G.Finch - RDH - gfinch@rdh.com 11

12 Site Protection & Sequencing Site Protection & Sequencing Far North G.Finch - RDH - gfinch@rdh.com 12

13 Managing Exposure - Wall Assemblies Drained & ventilated rainscreen clad walls have been standard on essentially all mid-rise wood-frame buildings in Pacific Northwest for more than the past decade A minimum code requirement for most western jurisdictions and good practice in all climates for this height & exposure of building Details for drainage & ventilation equally as important! Why Rainscreen for Mid-rise Wood? Significantly improves wall assembly & cladding durability reduces risk Rainscreen cavity also allows for wood-frame construction tolerances to be concealed behind cladding A 3/4 cavity created by vertical strapping/furring most common in mid-rise wood-frame is above code minimum 3/8 (10 mm) Strapping also helps keep WRB/AB membrane in place during construction G.Finch - RDH - gfinch@rdh.com 13

14 Rainscreen Claddings Exterior Insulated Rainscreen Claddings G.Finch - RDH - gfinch@rdh.com 14

15 Water Resistive Barriers in Mid-rise Wood-frame Water Resistive Barrier, WRB (aka sheathing membrane) Secondary plane of moisture protection & innermost plane that can safely manage moisture and drain & dry it back out Many different products available (mechanically fastened, self-adhered, & liquid applied) Many products can also be taped/sealed/applied as air barrier discussed later Both vapour permeable & impermeable products available choice depends on insulation placement & wall design Care with Impermeable Materials and Wet Wood Need to be careful with the use of vapor impermeable materials over wood that is wet or could get wet in service Self adhered membranes Metal flashings Foam plastic insulations* Vapor diffusion wetting & drying ability for assemblies & details should always be assessed ensure balance G.Finch - RDH - gfinch@rdh.com 15

16 Vapor Retarders / Barriers Vapor Retarders / Barriers control the diffusion of vapor through an assembly Limit wetting (condensation) At same time there is a desired to promote drying Gets more complicated with exterior/split insulated assemblies & selection of AB/WRB materials and exterior insulation types Vapour Control with Wood-frame Exterior Walls Interior vapour barrier Polyethylene, polyamide Smart Vapour Retarder or Vapour Retarder paint most common for standard wood-framed walls Canada Poly most common US Vapour Retarder paint or Smart Vapour Retarder more common Vapour control strategies are reassessed in walls with exterior or split insulation Interior Vapour Barrier does not need to be the primary air barrier G.Finch - RDH - gfinch@rdh.com 16

17 Other Vapour Retarder / Barrier Materials Concrete, glass, metal, plastics Polyethylene sheet Impermeable peel & stick Vapour barrier paint, smart vapour retarder Wallpaper XPS, EPS & Polyiso Closed-cell sprayfoam Plywood/OSB (at low RH levels) Plywood and OSB - Impact of RH on Vapor Permeance Permeance (ng/pa s m2) mm OSB Plywood ~20 perms mm Plywood ~0.5 to 2 perms OSB ~6 perms 0 0% 20% 40% 60% 80% 100% Relative Humidity See ASHRAE Handbook of Fundamentals & Other Sources for Vapor Permeance with RH G.Finch - RDH - gfinch@rdh.com 17

18 One Not So Great Practice Developed in BC DO NOT DO THIS Air Barrier Systems, Materials & Trends G.Finch - RDH - gfinch@rdh.com 18

19 BRAND Toronto Wood Solutions Fair Air Barriers for Mid-rise Wood Buildings Air Barrier Systems must: Be Continuous Be Durable Resist Structural Loads Sufficient Stiffness & Strength for Design Wind Load Be Airtight Not negatively affect durability or vapor diffusion drying ability Air barrier materials and approaches suitable for low-rise buildings may not be appropriate for mid-rise (5&6 storey) wood-frame Air Barriers are Systems BRAND House Wrap Materials Components Accessories Whole Building Airtightness G.Finch - RDH - gfinch@rdh.com 19

20 Many Wood-frame Air Barrier System Options Choice depends on a variety of factors including wall design & builder familiarity with system Common Air Barrier Systems Sealed Polyethylene (mastic & tapes) Airtight Drywall (drywall/gaskets/sealant) Sheathing Membrane (mechanically attached, taped & sealed) Sheathing Membrane (self adhered or liquid applied) Sealed Sheathing Board (sealants/tapes at joints) Spray Polyurethane Foam & sealants Airtightness Does Not Happen By Accident G.Finch - RDH - gfinch@rdh.com 20

21 Building Enclosure Assembly Detailing (WSS) (WRB) (AB) (VR/VB) (Insulating Materials) Wood-frame Mid-rise Air Barrier System Trends Trend towards exterior air barrier approaches (at sheathing plane) relying on rigidity of wood/gypsum sheathing Sealed sheathing membrane approach Mechanically Attached (Taped & Sealed), $ Self-adhered Membranes, $$$ Liquid/Fluid Applied, $$$ Sealed sheathing approach (plywood/osb/gypsum) Sealed joints (good sealant or tapes), $$ Use of interior approaches not as common for mid-rise Sealed poly not appropriate for height Airtight drywall not widely used G.Finch - RDH - gfinch@rdh.com 21

22 Mechanically Attached Air Barrier Membranes Loose sheet mechanically attached to wall with cap staples/nails and sealed with tapes, self-adhered membrane and sealants Challenges with Mechanically Attached Air Barriers & Wind During Construction G.Finch - RDH - gfinch@rdh.com 22

23 Rigid Support for Mechanically Attached Air Barriers During Construction & In-Service Exterior Insulation Sandwich Support for Mechanically Attached Air Barriers G.Finch - RDH - gfinch@rdh.com 23

24 Mechanical Attached Air Barriers & Masonry Interfaces & Challenges Balconies & Roofs G.Finch - RDH - gfinch@rdh.com 24

25 Interfaces & Challenges - Penetrations Mechanically Attached Air Barrier Details Pre-stripping AB membrane is often recommended at framing interfaces & roof-wall transitions but usually forgotten! G.Finch - RDH - gfinch@rdh.com 25

26 Interfaces & Challenges Parapet Solutions Interfaces & Challenges Parapet Solutions G.Finch - RDH - gfinch@rdh.com 26

27 Sealed Sheathing Approach Air Barrier Joints in sheathing (Plywood, OSB, Gypsum) are sealed with good sealant (usually silicone), strips of selfadhered membrane, or high-quality tapes Sealed Sheathing Approach Air Barrier G.Finch - RDH - gfinch@rdh.com 27

28 Sealed Sheathing Approach Air Barrier Sealed Interior Sheathing (Pre-fab Wall) G.Finch - RDH - gfinch@rdh.com 28

29 Sealed Sheathing Approach Water Protection Mechanically attached Water Resistive Barrier (WRB) loosely installed over top of sheathing, but not taped and detailed as the air barrier Case Study: Portland, Orchards Passive MURB Orchards at Orenco, Walsh Construction G.Finch - RDH - gfinch@rdh.com 29

30 Self-Adhered Air Barrier Membranes Self-adhered membranes (typically vapour permeable) applied to exterior wood sheathing along with tapes/self-adhered membranes at interfaces Self-Adhered Air Barrier Membranes G.Finch - RDH - gfinch@rdh.com 30

31 Self-Adhered Air Barrier Membranes Provides benefits of full sided wrapping for ease of detailing, addressing soffit/sloped details and shipping Liquid/Fluid Applied Air Barrier Membranes Liquid/Fluid applied membranes (roller, brush or spray) applied to sheathing with sealants/tapes or reinforcing at all joints, gaps, and fasteners G.Finch - RDH - gfinch@rdh.com 31

32 Applying Liquid Applied Air Barrier Membranes Joints in Liquid Applied Air Barrier Membranes G.Finch - RDH - gfinch@rdh.com 32

33 Joints in Liquid Applied Membranes Hybrid Approaches Liquid applied membrane window rough openings becoming common approach with various air barrier approaches cost effective & simpler than SAM origami G.Finch - RDH - gfinch@rdh.com 33

34 Air Barrier Challenges & Material Compatibilities SBPO house wrap special silicone Foil faced SAM Below grade Granulated SBS membrane Concrete Foundation wall Silicone membrane over plywood Silicone sealant at joints and fastener holes Foil-faced SBS Below grade SBS over Concrete Foundation Cement board over XPS New AB/WRB Materials in a Growing Market Many new self-adhered and liquid applied vapour permeable sheathing membranes available on the market Fills a niche of a combined vapour permeable air-barrier/ WRB on exterior of wood sheathing in mid-rise wood-frame buildings Current test standards slowly adapting to this class of materials G.Finch - RDH - gfinch@rdh.com 34

35 Lessons Learned So Far with New Membranes Not all products are created equal nor suitable for all substrates/applications Key considerations & potential issues include: Longevity, durability, exposure to UV & heat Compatibility & adhesion with other materials Flexibility and gap/crack bridging ability Curing or adhering in cold weather big issue in Canada Important properties negatively changing with time Wet Weather Challenges? G.Finch - RDH - gfinch@rdh.com 35

36 Compatibility Challenges? Long-Term Durability Challenges? G.Finch - RDH - gfinch@rdh.com 36

37 Cold Weather Application Challenges? Wood-frame Crack Bridging Challenges? Liquids Vapor permeable self-adhered sheets Liquids G.Finch - RDH - gfinch@rdh.com 37

38 How Well is the Industry Doing WA State? How Well Is the Industry Doing WA State? Airtightness [L/(s 75 Pa] WA State Requirement Liquid Applied (10 Buildings) 54 Buildings, Oct 2015 RDH SEA Data Leakiest tested Median & 1 st /3 rd quartile range Tightest tested Sealed Sheathing (11 Buildings) Sheet Applied (28 Buildings) Passive House Range equivalent ~ 0.6 ACH 50 Curtain Wall/Window Wall/Storefront (15 Buildings) Airtightness 75 Pa] G.Finch - RDH - gfinch@rdh.com 38

39 Passive House Airtightness <0.6 Pa ~0.035 cfm/ft Pa Self-adhered sheet membrane primary AB, transition to poly at ceiling Passive House Airtightness 0.13 Pa ~0.014 cfm/ft Pa Sealed sheathing primary AB transition to SA membrane at roof G.Finch - RDH - gfinch@rdh.com 39

40 Wood Framing, Energy Codes & Mid-Rise Wood Buildings Wood-Framing & Energy in Taller Wood Buildings 5&6 storey wood-frame buildings will typically have less room for stud space insulation (studs, tie-downs, services etc.) Creates challenges to meeting prescriptive R-value requirements without exterior insulation G.Finch - RDH - gfinch@rdh.com 40

41 Solid Wood (Cross Laminated Timber) Buildings Where does the insulation go here? Wood Framing Factor Impact on Effective R-values 24 o/c 16 o.c. G.Finch - RDH - gfinch@rdh.com 41

42 Energy Code Drivers for 5&6 Storey Wood-frame Building Enclosures While Energy Codes differ across Canada, the minimum effective R- value requirements for walls in mid-rise woodframe buildings is at or above a standard framed 2x6 wall with ~R-20 something batt insulation (= effective ~R-16) NECB 2011 ASHRAE 90.1 Ontario SB-10 (Part 3) ASHRAE 90.1 & NECB 2011 and Wood Buildings NECB 2011 Climate Zone Wall: Min.R-value Roof -Sloped or Flat: Min. R-value A/7B Minimum Effective R-values (IP) Climate Zone *7A/7B combined in ASHRAE 90.1 ASHRAE Climate Zone Wall Wood Res/Comm Min. R-value Roof Slope, Flat: Res/Comm Min. R-value , A/7B , , Res, 15.6 Comm 37.0, Res, 11.2 Comm 37.0, 20.8 G.Finch - RDH - gfinch@rdh.com 42

43 Ontario SB-10 & SB-12 SB-12 (Part 9 Buildings), Wall insulation targets of R-22 to R-29 nominal depending on climate zone & space heat type Prescriptively compliant wall assemblies consist of 2x6 with batts to 2x6 with batts + R-5 continuous exterior insulation SB-10 (Part 3 Buildings), modification of ASHRAE 90.1, Wood-frame wall R- values ~R-13 to ~R-22 effective depending on climate zone (tradeoffs available) So for 5&6 storey wood: 2x6 or 2x6+ Meeting Energy Code Wall R-value Targets with Exterior Insulation or 2x8 Framing Code shift of prescriptive effective R-value targets to R-20 range (from ~R-16 in previous codes): 2x8 framing (w/ R-28+ batts) Limited if cavity full of framing, services and tie-downs etc. 2x6 with 1 to 1.5 (R-4+) of exterior insulation ~R-16 ~R-20 ~R-20+ G.Finch - RDH - gfinch@rdh.com 43

44 Adding Insulation to Wood-Frame Walls Baseline 2x6 w/ R-22 batts = ~R-16 effective Exterior Insulation: R-20 to R-40+ effective Constraints: cladding attachment, wall thickness Good durability Split Insulation: R-20 to R-40+ effective Constraints: cladding attachment Good durability with proper design Deep or Double Stud: R-20 to R-40+ effective Constraints wall thickness Fair durability, sensitive to air/vapour Cladding Attachment through Exterior Insulation Longer cladding Fasteners directly through rigid insulation (up to 2 for light claddings) Long screws through vertical strapping and rigid insulation creates truss short cladding fasteners into vertical strapping Clip and Rail, Fixed clips with short cladding fasteners into vertical strapping/girts G.Finch - RDH - gfinch@rdh.com 44

45 Cladding Attachment with Exterior Insulation Continuous Wood Framing ~15-30% loss in R-value But 2x6 wall with R-22 batts and R-4 exterior = ~R-20 effective Cladding Attachment through Exterior Insulation Thermally Efficient Clip & Rail Systems G.Finch - RDH - gfinch@rdh.com 45

46 Cladding Attachment through Exterior Insulation Screws through Exterior Insulation & Vertical Strapping 5-Storey Wood-frame w/ Exterior Insulation G.Finch - RDH - gfinch@rdh.com 46

47 5 Storey Wood-frame w/ Exterior Insulation Prefabricated & Super Insulated ~R-40 pre-fabricated walls, 6 Rigid Mineral wool over 2x6 framed & insulated wall Passive House Certified G.Finch - RDH - gfinch@rdh.com 47

48 Prefabricated & Super Insulated Prefabricated & Super Insulated G.Finch - RDH - gfinch@rdh.com 48

49 Prefabrication for Tall Wood R-20 Panelized Wood Frame Walls Thicker Insulation = Really Long Screws 10 Exterior Insulation over CLT G.Finch - RDH - gfinch@rdh.com 49

50 Masonry Ties Case Study Thermally Efficient Masonry G.Finch - RDH - gfinch@rdh.com 50

51 Design for Wood-Movement & Shrinkage Behaviour of Wood in Construction G.Finch - RDH - gfinch@rdh.com 51

52 Wood Moisture Content vs Relative Humidity Site/Construction In-Service (High) Initial MC In-Service (Low) Wood shrinkage is 0.20% to 0.25% in dimension per 1% change in MC Behaviour of Wood in Construction Wood-frame Shrinkage Total shrinkage dependant on amount of tangential/radial grain wood and initial moisture content Differential movement is a real concern when detailing, especially for 5&6 storey wood-frame buildings Shrinkage generally in range of 1/4 per floor in dry cases, 3/8 to 1/2 per floor in typical cases, Up to 1 per floor in extreme cases Cumulative Shrinkage for 6 storey Wood-frame Building at roof eave G.Finch - RDH - gfinch@rdh.com 52

53 Behaviour of Wood in Construction Detailing for Differential Shrinkage is Most Important Wood-frame Shrinkage & Plumbing G.Finch - RDH - gfinch@rdh.com 53

54 Window Gutters.. Lessons Learned from Wood-frame Shrinkage G.Finch - RDH - gfinch@rdh.com 54

55 Lessons Learned from Wood-frame Shrinkage Lessons Learned from Wood-frame Shrinkage G.Finch - RDH - gfinch@rdh.com 55

56 Window Sill Sealant Joint Method But watch sealant compression stresses Window Sill Sliding Flashing Method G.Finch - RDH - gfinch@rdh.com 56

57 Window Sill Detail Sliding Flashing Method Window Head Detail Sliding Flashing Method Loose Lintel G.Finch - RDH - gfinch@rdh.com 57

58 Window Head Detail Sliding Flashing Method Balconies & Slope G.Finch - RDH - gfinch@rdh.com 58

59 Reducing Wood-frame Shrinkage at Floors Modified platform framing practices hung joists Traditional platform framing = maximum shrinkage potential Use of engineered lumber floor joists & headers Reducing Effects of Differential Shrinkage Fire-rated woodframed/solid wood stairwell & elevator shafts instead of concrete or concrete block Have run into issues with this detail with some AHJs and firetesting currently underway to demonstrate suitability G.Finch - RDH - gfinch@rdh.com 59

60 Adapting Design & Architectural Style Some Trends in Balcony Designs G.Finch - RDH - gfinch@rdh.com 60

61 Pre-Finished Steel Balconies & Wood Pre-Finished Steel Balconies & Wood G.Finch - RDH - gfinch@rdh.com 61

62 Maintenance & Renewals Considerations Maintenance and Renewals Recognize how the in-service stage of a building s life can impact maintenance and renewals Architectural design of building is impacted Accessibility and durability Above 4 storeys can no longer use a ladder! Need to provide fall arrest anchors for Bosun chair, swingstages Boom lifts movement around the building and structural support provided by garage roof slab G.Finch - RDH - gfinch@rdh.com 62

63 Maintenance and Renewals Dryer vent cleaning Easily accessible from balconies or roof? Additional lint clean-out Condensing units? Durable enclosure components Minimal maintenance claddings & finishes Durable Sealants Corrosion resistant metals Higher quality windows Summary Environmental Loads Increase in height = higher wind and rain loads More robust air barrier systems Improved water penetration control strategy appropriate assembly, materials and details - rainscreen Longer construction duration means more focus on drying and protection from moisture during construction Claddings & Materials Non-combustible claddings & in many cases noncombustible insulation Thermal Performance & Energy Efficiency More structure less room for insulation, other services G.Finch - RDH - gfinch@rdh.com 63

64 Summary Wood-frame Shrinkage Higher shrinkage in 5&6 storey wood-frame manage with: Limit amount of cross grain wood, modified platform framing & engineered floor joists/headers Use dry wood (and keep it dry) Horizontal compartmentalization and joints in cladding design Details are critical, plan for appropriate slopes after shrinkage Maintenance & Renewals Access for maintenance is a significant issue need to design for it & provide suspended access anchors Consider reduction in extent and frequency of maintenance required through choice of components and materials Additional Resources Building Enclosure Design Guide Wood-frame Multi-Unit Residential Buildings (HPO, 2011) Currently being updated with latest information & new details, release late 2015 Guide for Designing Energy Efficient Building Enclosures (HPO, CWC, FP Innovations, 2013) Illustrated Guide R-22 Effective Walls in Wood-frame Construction in BC (HPO, COV, 2015) G.Finch - RDH - gfinch@rdh.com 64

65 Discussion GRAHAM FINCH rdh.com This concludes The American Institute of Architects Continuing Education Systems Course Canadian Wood Council Wood WORKS! Ontario G.Finch - RDH - gfinch@rdh.com 65