Timber Framing for Non-Residential Construction - Fire Tower

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Timber Framing for Non‐Residential Construction

“Wood is universally beautiful to man, and the most humanly intimate of all [building] materials.”

Frank Lloyd Wright

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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.

Thank you!

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Learning ObjectivesAt the end of this program, participants will be better able to:

• Compare the sustainability of heavy timber as the structural system versus steel or concrete. Focus will be on its natural renewability, sustainability, embodied energy, longevity, adaptability and reuse.

• Identify the structural soundness and integrity benefits that heavy timber brings to buildings and other structures. Focus is on the clear load paths, structural redundancy, structural flexibility, and timber’s longevity.

• Safely and responsibly incorporate heavy timber into designs and plans of non‐residential buildings. Focus will be on aesthetics, timber species, moisture content, natural resistance to bio‐agents, and fire resistance.

• Guide and evaluate the choice of heavy timber joinery style for various types of building programs, understanding the limitations of each choice. Focus will be on traditional joinery and steel assisted joinery and such factors as cost, strength, ductility, moisture content and exposure affects.

Agenda

• Introduction

• Heavy Timber context in non-residential construction

• Sustainability

• Timber Basics—From material choice through enclosure

• The best style of Heavy Timber joinery for your project

• Getting started on your Timber Frame project

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IntroductionMack Magee

• Currently:

Principal, Fire Tower Engineered Timber

Principal, FraserWood Industries

• Formerly:

General Manager, Cascade Joinery, Washington

Director of Operations, Riverbend Timber Framing, Michigan

Manager Civil Engineering, Corporate Engineering, Owens Corning

Sourcing Manager, Packaging Commodities, Owens Corning

And, many other positions, too numerous to mention…

• Education:

Masters of Science, Civil Engineering, Stanford University, 1986

Bachelors of Science, Civil Engineering, Stanford University, 1985

Ancient Non‐Residential Projects

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Older Non‐Residential Projects

Timber as Structure

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Timber brings drama and visual interest

Denver Derrick, Denver Central Library, Denver, COArchitect: Michael Graves & Associates, Princeton, NJ

North Star Trading Post at the Toledo ZooArchitect: The Collaborative Inc., Toledo, OH

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Ashton Gardens Wedding Chapel, Corinth, TXArchitect: Cisneros Design Group, Houston, TX

Gettysburg National Military Park and Museum, Gettysburg, PAArchitect: LSC Design, Inc.

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YMCA, Phoenixville, PAArchitect: Kramer/Marks P.C. Architects AIA

Alpine Orthopaedic Clinic, Franconia, NHArchitect: Samyn D’Elia

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Kituwah Immersion Language Academy, Architect: Padgett and Freeman Architects

Oak Bluffs Marina Terminal, MV, MAArchitect: Maguire Group

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West Lebanon, NH StoreArchitect: Bensonwood

Bensonwood

Administration Building and Fabrication Shop

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Structural Form in Timber Architecture

That form ever follows function…

Though that function might be aesthetic


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Cruck Frames

Cruck Frames

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Log Timber Framing

Knee Braces

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What is Green about Timber?

How timber is green• Carbon sink

• Low embodied energy

• Renewable

• Recyclable

• Reusable

• Organic/Biodegradable

• Cleans air

• Cleans water

• Produces O2

• Habitat Source

Positive attributes• Avoidance of CO2

• Strong

• Lightweight

• Flexible

• Diverse

• Attractive

• Easy to fabricate

• Readily available

• Inexpensive

• Versatile

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Measure of Sustainability: Life Cycle Assessment

Life Cycle Assessment

transportation

energy use

extractioneffects

emissions to water

solidwaste

emissionsto the air

resourcedepletion

wateruse

Sustainable Measure: Life Cycle Assessment

Energy in Em

issions

Energy in Em

issions

Energy in Em

issions

Energy in Em

issions

Energy in Em

issions

Waste out

Waste out

Waste out

Waste out

Waste out

Raw materialacquisition

Materials manufacturing

Product manufacturing

Product use or

consumption

Final disposition

reuse & recycle

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Sustainability Comparison for Three Structural Systems

0

200

400

600

800

1000

1200

1400

1600

Total Energy Use

Green

house Gas Index

Air Pollution Index

Solid

Waste

Ecological Resource Im

pact

Use

Wood

Steel

Concrete

GJ x 103

KG x 103 Index Value x 108

Index Value x 104

Index Value x 104

Source: Green By Design, published by Canadian Wood Counciland developed by Athena™ Life Cycle Assessment Software

• Total Energy Use (GJ x 102):- Steel requires 2.4x the energy use that wood does- Concrete requires 1.7x the energy use of wood

• Greenhouse Gas Index (Equivalent CO2 Kg x 103): - Steel produces 1.5x the mass that wood does- Concrete produces 1.8 x the mass that wood does

• Air Pollution Index (Index Value x 108):- Steel’s impact on our environment is 1.4x that of wood- Concrete’s impact on our environment is 1.7 x the energy that of wood

• Solid Waste Index (Index Value Kg x 104): - Steel’s impact on is 1.4x that of wood- Concrete’s impact is 2x that of wood

• Ecological Resource Impact Use (Index Value x 104): - Steel’s impact on is 1.2x that of wood- Concrete’s impact is 2x that of wood

Sustainability Comparison for Three Structural Systems

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Carbon Sequestration

CO2 + H2O + SUNLIGHT ==> O2 + (C5H10O5)n (sugars)

Carbon Sequestration• Typical timber frame is +/- 12,000 bf (28 m3)

• 50% of the dry weight of wood is carbon

• 1 m3 of Douglas fir contains 0.225 tons of

carbon (not CO2)

• So, a typical timber frame contains 6.37 tons

of carbon (about as much as this tree)

• If left to decay, this carbon would generate

23.5 tons of CO2 (CO2 = 3.7 x C)

• Or, about the same emissions from 2400

gallons of gasoline

• As a result, wood has a negative carbon

footprint

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Carbon Sequestration• 3.5 billion metric tons of carbon stored in U.S. wood products

-- 670 million car-years of emissions

• Approximately 60 million metric tons are added each year

-- 11 million car-years of emissions

• Most of this wood is in the housing stock

• More of it could go into non-residential buildings

• When the wood is substituted for steel, concrete and plastic,

50% to 100% CO2 emissions can be avoided

• N.A. forestry firms obtain 65% of their energy needs from

bio-massSource: Green By Design, published by Canadian Wood Council

Carbon Sequestration Examples

ProjectVolume of wood used(cubic feet)

Time for forests to grow this fiber

(minutes)

Carbon Sequestered(metric tons)

Avoided emissions(metric tons)

Estimated carbonbenefit

(metric tons)

Cars‐yearsemissions/House –years of energy

Avalon Anaheim Stadium California

183,600 15 3,970 8,440 12,4102,369 cars 1054 houses

El Dorado HS Arkansas

153,140 13 3,660 7,780 11,4402,184 cars972 houses

New Earth Market California

2,825 0.25 70 160 23044 cars

20 houses

Source: Tackle Climate Change—Use Wood published by BC Forestry Climate Change Working Group

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Sustainable Forestry

91

90

86

82

68

66

64

63

60

40

29

26

21

16

6

0 10 20 30 40 50 60 70 80 90 100

Canada

Norway

Sweden

Finland

Russian Federation

Brazil

Indonesia

Malaysia

United States

Chile

New Zealand

Germany

China

France

United Kingdom

Per Cent of Original Forest

Sustainable Forestry• Many countries still have a large percentage of their original forests• North America not only has millions of hectares, it is largely original

Source: World Resources Institute Data Tables, 2000‐2001

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Sustainable Forestry• Rate of deforestation has fallen from 8.3M to 5.3M hectares (36%)• Heartening that two of most populous countries have largest increases

‐0.6 ‐0.4 ‐0.2 ‐1E‐15 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

CHINA

NORWAY

INDIA

SWEDEN

UNITED STATES

CANADA

RUSSIA

SUDAN

PERU

ANGOLA

COLOMBIA

MEXICO

AUSTRALIA

BRAZIL

INDONESIA

2000‐2010, Average annual change, %

Nil change

Nil change

Source: The World’s Forests Sylvan States, The Economist, 11Feb11

180

21

18

18

9

8

6

4

3

2

0 20 40 60 80 100 120 140 160 180 200

N.AMERICA

FINLAND

SWEDEN

RUSSIA

AUSTRALIA

GERMANY

BRAZIL

MALAYSIA

FRANCE

CHILE

MILLIONS OF HECTARES CERTIFIED

Sustainable Forestry

• Only 10% if the world’s forest are independently certified• Over 50% of those forests are in North America (2008)

444million acres

Source: World Resources Institute Data Tables, 2000‐2001

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Certified Wood in North America

(American Forest & Paper Association)

(Canadian Standards Association)

Timber Basics: Species Choice

Commonly used for commercial projects• Douglas Fir• Southern Yellow Pine• Red Oak• White OakOther popular species• Eastern White Pine• Cypress• Hemlock• Spruce• And, many others

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Douglas Fir

White Oak

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Red Oak

Southern Pine

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Antique Timber: Reused

Industrial SalvageRecycled/Reclaimed

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Forest Salvage/Standing Dead Wood

Reclaimed Shipbuilding Timbers

SalvagedTimber

River Salvage Timbers

Glue Laminated vs

Solid Sawn

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Organic Forms are Easy with Glulams

Curved Timber

• GrainMatched™ Glulam

New Energy Works

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Elegant Curves

FraserWood

How Timber is Sawn Boxed Heart

Evergreen Specialties

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How Timber is SawnFree of Heart Center (FOHC)

Timber Basics: How Timber Dries—Boxed Heart


Timber Structure & ShrinkageLongitudinal: Parallel (roughly) to the direction of the cell fibers.

Shrinkage ranges between 0.1% to 0.2% from green to oven dry.

Radial: Perpendicular (roughly) to the growth rings.

Shrinkage ranges between 2.1% to 7.7%.

Tangential: Coincident (roughly) with the growth rings.

Shrinkage ranges between 4.4% to 12.7%.

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FraserWood

Shrinkage

Quartersawn

Flatsawn

Boxed Heart

Bastard SawnFree of Heart Center

From Wood Handbook by FPL

FraserWood

Note that the shrinkage is not linear from a FSP of 30% to 24%

From 24% to oven dry, the shrinkage is mostly linear.

Roughly, a timber will shrink from green at 24% to 8% in WY environments. At 19%, it has seen only 1/3 of its shrinkage.

Shrinkage

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Shrinkage

Boxed Heart Free of Heart Center


Conventional Kiln DryingIndirect steam heat‐‐convection

• Humidity is removed via a system of vents

• Cool dry air is introduced at one end

• Warm moist air is expelled at the other

• Use of steam increases heat transfer

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Radio Frequency Kiln Drying

FraserWood

• Capacitance heating (volumetric)—whole volume at once

• Lower temperature

• Faster timber drying—5 to 8 days for timber

• Designed for timber—it will dry timber

Radio Frequency Kiln Drying

FraserWood

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Timber Basics: Rate of Growth

Fabrication

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Power Tools on Steroids

Precision Hand Tools

Precision not typical in commercial work

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Handcrafted Joinery

CNC Fabrication

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CNC Joints

Crane Raising

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Structural Insulated Panels

(SIPs)

Timber Frame Basics: Enclosure

Foam Core

• Expanded Polystyrene (EPS)

• Extruded Polystyrene (XPS)

• Polyurethane & Polyisocyanurate

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SIP Thickness R-Value Perm

4.5” 15 0.61

6.5” 23 0.43

8.25” 30 0.35

10.25” 37 0.28

10.5” 38 0.27

12.25” 45 0.24

12.875” 48 0.19

15” 56 0.19

17” 63 0.17

25” 94 0.12

SIP Size & Thickness

• Jumbo Panels 8’ x 24’

Frame Embellishments

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Finial

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Chamfered Edges

Surface Treatment

• Planed

• Rough Sawn

• Hewn

• Adzed

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Planed

Adzed

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Hewn

Rough Sawn

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RoughSurface

Treatment

Determining the style of joinery

• All wood

• Wood with hidden metal connections

• Wood with exposed metal connections

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Joinery Style: All Wood

Bensonwood

Any structure is a collection of connections held together with members.

Hammerbeam Trusses

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Joinery: Steel Gussetts

Fink Truss

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Cast Steel ConnectionHardware

Getting Started

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How do you find a qualified, experienced Timber Frame Company?

• Searchable database on www.timberframe.org,

Structural Engineer of Record (SER)vs

Specialty Structural Engineer (SSE)

• Structural Engineer of Record – responsible for the entire structural frame and foundation

• Specialty Structural Engineer – responsible for the timber frame only

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Where to Find a Qualified Engineer

The Timber Frame Business Council Website Has a “Find a Timber Frame Engineer” Map at http://www.timberframe.org/timber-frame-engineer.html

Includes engineers licensed in each state/province.

• Questions?

• Comments

• Complaints?

Thank You

Wood is the most humanly sympathetic of all building materials because it affects so many of our senses…it may even be that our appreciation of proportion comes from the natural dimensions of trees.

Peter Davey, Editor, The Architectural Review

Timber Framing for Non-Residential Construction - Fire Tower

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