Overview of FPInnovations’ New Mid-Rise...

© 2015 FPInnovations. All rights reserved. Copying and redistribution prohibited. ® FPInnovations, its marks and logos are trademarks of FPInnovations.

M. Mohammad, P.Eng., PhDResearch Leader/FPInnovations

November 24, 2015, Toronto

WoodWorks! ON Wood Solutions Fair

Overview of FPInnovations’ NewMid-Rise Handbook


Background & Motivation

The urban geography is changing▫ Population, demographics, sustainability …▫ Light industry being pushed outside urban

centres - lower revenue for municipalities▫ Land value increasing – demanding higher value

buildings▫ Cost of building and maintaining municipal

infrastructure is increasing

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Densification lowers cost of providing services (e.g. utilities, transit)

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▫ Conversion of single family to townhouses or multi-family

▫ Mixed uses to provide services close to residences

http://ibis.geog.ubc.ca/courses/geob479/classof08/vandensify/home.html



There is a need for densification but there is resistance to densification Municipal governments attempt to minimize

effects of increased density & provide benefits through▫ Planning, zoning, architectural features▫ Incentives to developers▫ Access to amenities, mixed occupancies

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World Housing….. Worldwide, up to 3 billion people will need a new

home in the next 20 years Push for urbanization: 50% today.. 75% in 2040! Cities are built from steel and concrete Steel and concrete, however contribute over 8%

of World’s GHG emissions


Green BuildingsGreen building materials made from bio-based or renewable resources and low in embodied energy and carbon are re-emerging


WOOD: Key Part of the Solution

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As construction material, WOOD is • Adaptable, renewable, and sustainable• Cost effective & efficient • Versatile and flexible – easy to work with..• Light weight, strong yet with ductility • Wood is good insulator • Wood is warm with natural beauty

VanD

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arden Visitor C

entre


Wood is GREEN

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o Wood is the only renewable and sustainable construction material

o Canada rate of deforestation is zero for over two decades (United Nations FAO State of the World’s Forests report issued in March 2007).

o Canada retains more than 90% of its original forest area (more than other countries) [Source: World Resources Institute Data Tables, 2000-2001]

o Sustainable Forest Management through 3rd party certification

• CSA Canadian Standards Association • FSC Forest Stewardship Council & • SFI Sustainable Forestry Initiative


Midrise Wood Frame Construction in Canada: The Story 2009: BC Building Code

revised to increase height limit for wood-frame construction from 4 to 6 storeys

2013: Quebec Building Code 2015: Ontario Building Code 2015: Alberta Building Code 2015 National Building Code of

CanadaKamloops, BCPhoto Courtesy of BC WoodWorks!

Expecting 1000’s of midrise buildings in Canada next few years!!


Modern Mid-rise Wood Frame Construction (Residential - C)

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Historical Tall Wood Buildings in Canada

Before 1941, before the 1st NBCC…▫ Vancouver, up to 9-storey, ~1900s▫ Toronto, up to 8-storey, ~ 1890s▫ Montreal, up to 7-storey, ~1860s

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Brick & Masonry

Heavy timber


Unfortunately…

o Construction of such buildings stopped mainly due to the introduction of modern building codes (NBCC 1941)

o Limits on wooden building height & areas were introduced (i.e., combustible vs. non-combustible construction concepts)

However, wood is making a comeback!!

Modern Building Codes


Rediscovered Taller Wood BuildingsThe LandingVancouver, 1905Height: 30 m NBCC 1941 (7)

National Building Code

NBCC 1953 (4)

NBCC 2015 (6)


Expanding Wood Use in Mid and High-rise Buildings

Over the last 10 years, significant efforts by federal & provincial governments and industry to expand wood use in the non-res. and mid & high rise construction sectors

o Examples: FPInnovations (TT Next Generation Building Systems and

Products); CLT handbooks, TWB Guide, Mid-rise WFC Guide

CWC/WoodWORKS! initiatives

Universities (NEWBuildS – Investment in the Forest Sector)

NRC/CWC/FPI mid-rise project – fire, acoustic and building envelope research to support mid-rise code changes


2012 OBC and Mid-rise WF Code Provisions

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o Previously, the max. height of a building of wood construction in OBC was 4 storeys (in-line with the 2010 and older editions of NBCC)

o As of January 1, 2015, the OBC permits wood construction for residential, business; and office services occupancies with a max. height of 6 storeys

o Intent is to provide opportunities/options for designers & builders to develop innovative, flexible and affordable new mid-rise buildings


WoodWORKS! 2015 Reference Guide on Mid-rise Wood Construction

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o Published by ON Wood WORKS!

o Guide documents the application of the ON Building Code (OBC) for use of wood in mid-rise construction

o Guide identifies required features, conditions or restrictions

o Developed by Morrison HershfieldLimited (MH) and released early in 2015


The MWFC Initiative

Mid-rise Wood Frame Construction (MWFC)▫ Natural extension to 3-4 storeys wood frame▫ Builds on current capacity and supply chain▫ Addresses the move to higher density zoning and

mixed residential/mercantile▫ In areas formerly zoned single family (SF)▫ Surrounding areas can continue to be SF

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Challenges: Mid-Rise Wood Frame (MRWF) Multiple / mixed occupancy

High degree of engineering required

Increased vertical live and dead loads and lateral wind and seismic loads

Higher fire resistance ratings for fire separations

Higher acoustic ratings between units

Differential movement between materials

Wood; cumulative shrinkage & compression perp.

Fire Safety During Construction Guidelines (Ontario)


FPInnovations’ Mid-rise Wood Frame Construction Handbook

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The MWFC Initiative

CWC / WoodWORKS! were instrumental in initiating the move to MWFC▫ NRCan, the Gov’ts of BC, ON and Quebec, and

other provincial agencies▫ FPInnovations working with partners, namely

CWC, NRC, RBQ

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FPI Mid-Rise Wood-Frame Handbook

Handbook aims at providing guidelines for properly designing and detailing wood-frame construction in agreement with national and provincial building code provisions

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Focus on mid-rise (5-and 6-storeys) light-frame wood construction In accordance with

2015 NBCC provisions and CSA O86-14

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Multi-disciplinary handbook involving a broad range of industry, research & design experts

FPInnovations, CWC, NRC and practitioners

Peer-reviewed Complimentary to other

existing manuals (CWC, NRCC, etc.)

Released early Nov. 2015


Table of Contents

Chapter 1: Introduction Chapter 2: Structural Products Chapter 3: Structural Design Chapter 4: Floor Vibration Control Chapter 5: Vertical Differential Movement Chapter 6: Fire Safety Design Chapter 7: Noise Control Chapter 8: Durable & Efficient Building

Enclosure Chapter 9: Elevator Shafts and Stairwells Chapter 10: Prefabricated Systems

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Overview of Structural Wood Products

Structural Wood Products and Components▫ Dimensional lumber, FJ lumber, panels, I-joists,

trusses, glulam, SCL, CLT Structural Assemblies▫ Conventional floor/roof/wall, mid-ply shearwalls

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Structural Design

Design provisions Design analysis Determination of building period Deflection of stacked multi-storey

shearwalls Dynamic analysis Diaphragm flexibility Capacity-based design method

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Structural Design: As Per CSA O86-14

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Structural Design

High-capacity diaphragms and shearwalls including FPI’s Mid-ply shearwall system

Force transfer around openings in walls Design for podium structures (seismic)▫ Also discussed under fire safety

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Nails work in double shear thus increasing the lateral load capacity

Greater edge distance - panel chip out failure is reduced

Nail head away from panel surface - nail pull through failure is prevented

Capable of accommodating additional sheathing

Nail in single shear

Nail in double shear

Sheathing Stud or

Plate

Grain direction

89 mm Stud or

Plate

38 mm 38 mm

Structural DesignFPI’s Mid-ply Shearwall System

Typical shearwallSingle shear plane

Mid-ply shearwallNail in double shear


Floor Vibration

Fundamentals (why, how and what) Review of existing design methods/gaps New design method Worked examples Field control and

remedy System approach

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Curtsey of sound proofing company


Vertical Differential Movement

Causes of vertical differential movement Predicting vertical movement Solutions to reducing and accommodating

vertical differential movement Recommendations

31Images: HPO 2011



Wood shrinkage (major cause)▫ Primarily contributed by horizontal wood members▫ Amount depends on MC change and shrinkage coefficient

▫ Loading (relatively small cause)▫ Closing of gaps between members

(settlement, bedding-in)▫ Elastic compression▫ Time-dependent deformation

(creep)▫ All influenced by loads and wood MC

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Longitudinal



Always design to allow certain differential movement▫ Detailing for major interfaces provided in the chapter

Measures to reduce/accommodate wood shrinkage and differential movement▫ Use and maintain drier wood in construction▫ Use engineered wood for floor joists▫ Good construction sequencing to reduce wood

wetting, encourage drying, and allow settling before enclosure

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Fire Safety Design

Fundamentals Combustibility of materials Fire separations Penetrations in fire separations Fire-resistance Firewalls

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Fire Safety Design Service spaces and Service facilities Interior finish Safety between floor areas Performance-based fire design Fire safety during construction

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Fire Safety Design

Fire separations

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Fire Safety Design

Penetrations in fire separations

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Image : Hilti

Image : STI Fire Stop inc.


Fire Safety Design

Fire safety during constructionThrough proper construction site management/strategies

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No more!


Fire Safety Design

Other considerations▫ Podium structures▫ Firefighters’ assumptions▫ Elevator shafts and Exit stairs

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Fire Safety Design

Podium structures (small and large)

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Photos: G. Triggs


Fire Safety Design

Elevator shafts and Exit stairs

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Noise Control

Fundamentals (why, how and what) Review of the NBCC requirements Design for occupants satisfaction

(2015 NBCC requirementfor ASTC)▫ Flanking, FSTC, FIIC

Strategy for noise control Noise control through design

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After C. Benedetti 2010, “Timber buildings”


Noise Control

Noise control through construction Workable and cost effective solutions

for mid-rise wood walls and floors Sound insulation of wood elevator shafts and

stairwells

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Curtsey of sound proofing company


Durable & Efficient Building Enclosure

Current energy codes and requirements Environmental loads Durability Thermal efficiency Building enclosures Natural durability and preservation treatments

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Elevator Shafts & Stairwells

Code provisions▫ Shrinkage, lateral loads and deflection,

connections, fire separations, acoustic Non-combustible shafts Wood-based shafts Hybrid

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Prefabricated Systems

Prefabricated systems▫ Wall, floor and roofing panels Certification standards▫ CSA A277 (under revision) Qualification of prefabricated systems Transportation Future trends

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Summary of the Overview

Multi-disciplinary handbook involving a broad range of industry, research & design experts

Handbook aims at providing guidelines for properly designing and detailing light-wood frame construction in agreement with provincial and national code provisions

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Acknowledgments

Natural Resources Canada (through TT program)

Government of BC BC Forestry Innovation Investment Government of Alberta Gouvernement du Québec (MFFP) Partners▫ Canadian Wood Council▫ National Research Council

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Urban Densification

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Source: businessimmo

Provide building solutions that meet the evolving demands due to macro changes in demographics


Mid-rise WF Construction with Concrete podium (mixed occupancy – Group C & D)

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38 89 mm lumber stud spaced at 406 mm o.c. 1.22 2.44 m wood-based panel Sheathing fastened to the narrow face of framing members

1.22 2.44 m wood-based panel at the center of the wall 38 89 mm lumber stud rotated 90 degree to those in

standard shearwall Sheathing fastened to the wide face of framing members

Standard shear wall2x4 studs

16” 16” 16”

Sheathing

Drywall/Sheathing

Structural DesignFPI’s Mid-ply vs. Standard Shearwall System

MidplyTM shear wall

Drywall/Sheathing

Cladding/SheathingSheathing


2012 OBC and Mid-rise WF Code Provisions

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o OBC prescribes the min technical reqs. for the design & construction of new buildings in ON

o OBC objectives are safety, health, accessibility, property protection, resource conservation, environmental integrity and conservation of buildings

o 2012 Edition of OBC came into effect on January 1, 2014

o Several amendments made to the Code since then including “Mid-rise” wood frame provisions (approved in 2014)


Overview of Mid-rise Code Provisions for in OBC

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o Provisions that permit or prohibit wood as a construction material are given in Parts 3 & 9

o Part 9 is applicable to “small” buildings up to 3 storeys & up to 600 m2 in area with restrictions on occupancy type

o Part 3 is applicable to any building larger than this, and a building of any size that contains assembly, care, or high hazard industrial occupancies

o Parts 4, 5 & 12 generally do not explicitly require or prohibit wood but rather set out the required performance criteria for structural, envelope and energy elements that every building must meet

© 2015 FPInnovations. All rights reserved. Copying and redistribution prohibited. ® FPInnovations, its marks and logos are trademarks of FPInnovations. 54

Amendments to Ontario’s Building Code Allowing Mid-Rise Wood Frame Buildings

o Buildings may include other “mixed use” occupancies below the 3rd floor, specifically, “Group A-2” and “Group E” (e.g., restaurants, grocery stores, etc.)

o New Articles (3.2.2.43A & 3.2.2.50A) introduced and prescribes the construction reqs. and area limitations for mid-rise buildings of combustible construction

o 3.2.2.43A can be applied to buildings less than 5 storeys in height but with larger building areas

(Ref: 2015 Reference Guide by MH, 2015)


Overview of Mid-rise Code Provisions in OBC

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Additional safety provisions not currently required in 4 storeys WF buildings will be applicable to mid-rise WF buildings:

o Enhanced automatic sprinklering to the NFPA 13 standardo Sprinklering of all balconies over 610mm deepo Building height limits including height limits to the fire access routeo Exterior cladding and roof covering be NC or combustion-resistanto Additional compartmentalization for large sprinklered spaces (e.g.,

attics)o At least 10% of bldg perimeter within 15m of a fire safety access routeo Exit stairwells have a 1.5 hour FRR & be of NCo Designed for higher seismic loads than similar NC buildingso More robust occupancy permit requirements


o Restrictions on irregularities (Sentence 4.1.8.10.(4))

• For medium and high seismic zones (IEFaSa(0.2)>=0.35), Type 4 or 5 Irregularities not allowed in 5 or 6 storeys of continuous wood construction

Overview of Mid-rise Code Provisions for in OBC: Structural

(Source: Wang, CWC, 2014)


Overview of Mid-rise Code Provisions for in OBC: StructuralOnly for seismic designo Increased static design force level (Sentence 4.1.8.11.(11))

• If period is determined using methods other than the empirical code period, static base shear shall be increased by 20%, but need not exceed the max.

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o Increased dynamic design force level (Sentence 4.1.8.12.(12))• Period determined using methods of mechanics other than the

empirical code period, the base shear shall be the larger of dynamic design force and 100% of static design force


OBC Mid-rise WF Provisions: Group C Residential Construction Reqs.: Fire

Curtsey of MH 2015 Reference Guide

o 4-storey: max building area of 2250 m² is permitted

o Prior to the 2015 amendments, a 4-storey WF area was limited to 1800 m²

o Similar max area limits increased for 1-to 3-storey buildings

o 5-storey WF, max. area of 1800 m² & 1500 m2 for a 6-storey

o 1-hr FRR for floor, roof and mezzanineassemblies (fire separations)

o If roof level is > 25m, require roof to be NC or FRT wood

o Allow NC roof be supported by combustible structural elements


Curtsey of MH 2015 Reference Guide

OBC Mid-rise WF Provisions: Group DOffice Buildings Construction Reqs.: Fire

o 5-storey: max building area of 3600 m², while 3000 m2 for a 6-storey

o 4-storey: max area of 4500 m². Prior to the 2015 amendments, a 4-storey wood building would be limited to 3600 m² in area

o Similar max. area limits increased for 1- to 3-storey buildings

o Similar reqs. to Group C for floor & roof fire separations (i.e., 1-hr FRR)

o If a firewall is used to separate a building into 2 or more bldgs and the required FRR of the firewall is 2 hrs (rating based on occupancies of the buildings), the firewall is not required to be constructed of NC material provided the buildings on each side of the firewall are sprinklered


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Thank you!M. Mohammad & Kenneth KooResearch Leader and Industrial [email protected]@fpinnovations.ca

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