BUILDING ENVELOPE 2014-01-15 By Sabrina D Ambra
2 OUTLINE Workplan Objectives Chp 6 Building enclosure design: Highlights Structural system Rainscreen system Prescriptive Path Results Design of Wall Design of Roof Remaining Tasks Questions
3 WORK PLAN OBJECTIVES Calculation of rain and wind load Choosing cladding type Review of chapter 6 Designing a rain screen Calculation thermal performance Calculating vertical movement (shrinkage and swelling) Designing joint details Understanding space acoustics Highlighting possible points of failure (wetting and drying) Proposing a roof design
CHP6 BUILDING ENCLOSURE DESIGN: HIGHLIGHTS Keys to Durability: Prevent excessive moisture accumulation, AND Allow wood to dry 4 Design Requirements Rainscreen strategy Exterior Insulation Air barrier Vapor permeable membranes/finishes required
Impacts Location of insulation Details CHP6 BUILDING ENCLOSURE DESIGN: STRUCTURAL SYSTEM 5 Envelope Assembly Post-and-beam with wood-frame infill INFILL: Non-load bearing, light wood frame
CHP6 BUILDING ENCLOSURE DESIGN: STRUCTURAL SYSTEM 6 Alternative: Mass Timber (CLT) Wood-frame infill walls: Non-load bearing
CHP6 BUILDING ENCLOSURE DESIGN: RAINSCREEN SYSTEM 7 Basic Elements Continuous Water Shedding Surface Cladding Drain holes/gaps Flashings @ all penetrations Airspace Ventilated Cavity (0.2 ACH) Drained to outside Continuous Air Barrier @ WRB layer
8 PRESCRIPTIVE PATH RESUTLS North Vancouver: Zone 5 (Table B-2 ASHRAE 90.1 (2010)) HDD 3000 Minimum Effective Assembly R-values NECB 2011: Above Grade, All Construction Types WALL : 3.597 Km 2 /W ROOF: 5.46 Km 2 /W
DESIGN WALL ASSEMBLY: WOOD STUD CAVITY WALL 9 Interior-Insulated (less preferred) Split-Insulated Designed R-value: 3.61 Km 2 /W Designed R-value: 4.62 Km 2 /W
Interior Insulated (less preferred) R-value: 3.61 Km 2 /W Thickness: 190 mm PRELIMINARY WUFI- WALL OPTION 1: INTERIOR INSULATED 10 Exterior-to-Interior Cladding (composite wood siding), 10.5 mm Vertical Strapping (?) Air Layer, 20mm Self-adhered Weather Resistive Barrier (sd=0.1), 0.1mm Blueskin VP TM 160 + adhesive-primers Exterior Gypsum Board, 13 mm Low density Glass Fibre Batt Insulation, 140 mm Interior Gypsum Board, 12.5mm
11 WUFI SIMULATION RESULT: INTERIOR INSULATED STUD WALL
PRELIMINARY WUFI- WALL OPTION 2: SPLIT INSULATED 12 Split Insulated R-value: 4.62 Km 2 /W Thickness: 210 mm Exterior-to-Interior Cladding (composite wood siding), 10.5 mm Vertical Strapping (?) Air Layer, 20mm Extruded Polystyrene Insulation (taped/sealed), 25.4 mm Self-adhered Weather Resistive Barrier (sd=0.1), 0.1mm Blueskin VP TM 160 + adhesive-primers Exterior Gypsum Board, 13 mm Low density Glass Fibre Batt Insulation, 140 mm Interior Gypsum Board, 12.5mm
13 WUFI SIMULATION RESULT: SPLIT-INSULATED STUD WALL
CLADDING ATTACHMENT OPTIONS: WOOD STUD WALL 14 Semi-rigid mineral-fibre insulation 2X6 Wood Framing w/ Batt Insulation SELECTED Rigid mineral-fibre insulation 2X6 Wood Framing w/ Batt Insulation
DESIGN WALL ASSEMBLY: MASS-TIMBER (CLT) 15 Exterior-Insulated
DESIGN WALL ASSEMBLY: CLT WALL 16 CLT, Exterior Insulation R-value: 3.55 Km 2 /W Thickness: 170 mm Exterior-to-Interior Cladding (composite wood siding), 10.5 mm Vertical Strapping (?) Air Layer, 20mm Extruded Polystyrene Insulation, 70 mm Self-adhered Weather Resistive Barrier (sd=0.1), 0.1mm Blueskin VP TM 160 + adhesive-primers CLT wall (4 layers) (15 mm/layer), 60 mm Interior Gypsum Board, 12.5mm
17 WUFI SIMULATION RESULT: CLT WALL
CLADDING ATTACHMENT OPTION: CLT PANEL 18 Semi-rigid mineralfibre insulation CLT panel
19 ROOF
20 ROOF OPTIONS
DESIGN ROOF ASSEMBLY: INVERTED/PROTECTED MEMBRANE 21 Low-slope, Exterior-Insulated
Low-slope, Exterior insulated R-value: 5.5 Km 2 /W Thickness: 230 mm DESIGN ROOF ASSEMBLY: INVERTED/PROTECTED MEMBRANE 22 Exterior-to-Interior Ballast (Expanded Clay aggregrate), 25 mm Filter Felt laminated polypropylene membrane, Exterior Gypsum Board, 13 mm Extruded Polystyrene Insulation (2 layers) (60mm/layer) WRB: Asphalt Impregnated Paper (60 min), 0.3 mm OR Vapour Barrier (sd = 1500) CLT deck (12 ply), 60 mm Interior Gypsum Board, 12.5mm
23 WUFI SIMULATION RESULT: INVERTED/PROTECTED MEMBRANE
DESIGN ROOF ASSEMBLY: GREEN ROOF 24 Green Roof, Extensive R-value: 5.46 Km 2 /W Thickness: 370 mm Exterior-to-Interior Soil, 150 mm PE membrane (sd = 87m), 0.2 mm Filter Felt laminated polypropylene membrane, Exterior Gypsum Board, 13 mm Extruded Polystyrene Insulation (2 layers) (60mm/layer) Vapour Barrier (sd = 1500) CLT deck (12 ply), 60 mm Interior Gypsum Board, 12.5mm
25 WUFI SIMULATION RESULT: GREEN ROOF
LOCATION & WEATHER STATIONS 26
LOCATION & WEATHER STATIONS 27
28 REMAINING TASKS Update Wall & Roof Assemblies (Feedback) Selection of Cladding (Non-combustible) Selection of Strapping for cladding Rerun Hygrothermal Simulations (WUFI) Update Climate File Design of roof drainage Design joint details for tall wood buildings Details for vertical movement due to shrinkage and swelling Complete Wind-Driven-Rain analysis Overhang design
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30 DISCUSSION & QUESTIONS Cladding: Combustible: Composite Wood-Siding Non-combustible: Stucco, Concrete board, vinyl siding, etc? Attachments: Strapping? Verticle strips of treated wood OR Light-gauge metal girts? Wall Assembly: Interior-insulated? OR Split-insulated Wood Stud wall? OR CLT wall? Roof Assembly: Type of Deck Green roof = OK for a portion of roof? Inverted/Protected Membrane for main roof = OK? Tapered Insulation? OR Tapered Structure?
31 REFERENCES 1. Blocken, B., Dezsö, G., van Beeck, J., & Carmeliet, J. (2010). Comparison of calculation models for wind-driven rain deposition on building facades. Atmospheric Environment, 44(14), 1714-1725. doi:http://dx.doi.org/10.1016/j.atmosenv.2010.02.011 2. Plescia, M. S., Eng, P., Lonescu, D., Simpson, M. B., Ge, H., & Krpan, R. Wind-driven Rain Study in the Coastal Climate of British Columbia. 3. Technical Guide for the Design and Construction of Tall Wood Buildings in Canada 4. Guide for Designing Energy-Efficient Building Enclosures: For Wood-Frame Multi-Unit Residential Buildings 5. The Performance of Rainscreen Walls in Coastal British Columbia, Graham Finch 6. ASHRAE 90.1 7. NECB 2011 8. Tall Wood 9. CLT Handbook Canadian Edition 10. CLT Handbook U.S. Edition
32 THANK YOU FOR LISTENING! ALMOST LUNCH TIME!