Design and Construction of Large Farm Building: Current Issues and Concerns

Ontario Building Officials Association Presentation by:Annual Meeting and Technical Sessions Will Teron, P.EngLondon, Ontario Senior Structural Engineer, Principal October 5, 2011 Tacoma Engineers

Outline

Introduction

Lateral Bracing

Fire Safety

Farm Building Code

Introduction

Tacoma Engineers

Tacoma Engineers has its roots in Guelph, Ontario where Jack Tacoma opened a sole proprietorship in 1980.

The firm has grown steadily to a staff of over thirty people, including professional engineers, project managers, technologists and administration staff.

We have been involved in the agricultural sector for over 25 years, and have proudly participated in the evolution of farm structures.

Contribute to scientific and technological advancements – advancements that require increased complexity, larger facilities, climate control and hygienic standards.

Will Teron, P.Eng.: Tacoma Engineers – Principal; Past President of CFBA; Chair – Ontario Technical Advisory Committee on Farm Fires

Introduction

Canadian Farm Builders Association

Canadian Farm Builders was founded in 1980 by a small group of farm builders that saw a need for uniformity and quality control within the industry.

Mission Statement: CFBA promotes standards and builds awareness through communication, education and advocacy for the betterment of the farm building industry.

Over 225 professional members including: Builders; Building Officials; Governmental Agencies; Engineers & Designers; Material and Equipment Suppliers

Current efforts: Fire safety in large farm building; National Farm Building Code of Canada

Lateral Bracing

Bracing provided to resist the lateral forces (wind) acting on the structure.

Two systems to consider:

Temporary bracing during construction

Permanent bracing

Lateral Bracing

Wind acts on structures

directly (positive pressure);

suction (negative pressure); and

uplift (negative pressure)

Need to consider overall stability and adequacy of sub-systems (trusses)

Open Sided Building – positive pressure on entire insideof building + outside pressures

Large Openings in Farm Buildings

Lateral Bracing

Large Openings in Farm Buildings

Lateral Bracing

Lateral Bracing

Overall Building Stability

Bracing options to address the building as a macro entity

Two basic options:

Knee braces

Diaphragm roof

Transfer loads to relatively stiff elements

Shear walls

Wind posts

Wall braces

Lateral Bracing

Knee Braced Building

Lateral Bracing

Diaphragm Roof

Lateral Bracing

Shear Wall Bracing

Lateral Bracing

Wind Posts and Buttress

Lateral Bracing

Wall Bracing

Lateral Bracing

Truss Bracing

Trusses are very slender elements that require bracing for stability

Temporary bracing of trusses during erection and construction is specified by TPIC.

External bracing (to ground) for overall support

Internal bracing (truss to truss) for stability

Lateral Bracing

Truss Bracing

Permanent bracing is specified by the building engineer and is based on the loads provided on the truss shop drawings.

Lateral Bracing

Truss Bracing

Approximately 2% of the web load is transferred into a lateral force.

Series of braces provided to resist the accumulated forces. Spacing of the braces is a function of the brace design.

Fire Safety

Fire Safety

Incidence of fires in farm buildings is increasing and the cost is growing at an alarming rate.

Large buildings are more difficult to extinguish unless enhanced fire fighting measures are included.

Majority of farm fires are deemed ‘preventable’. If standards were updated the extent of the fire damage could be significantly reduced.

Fire Safety

Ontario Dairy Farm: 100,000sf main barns plus milk house and secondary areas (350,000sf gross)

NFBC – Farm Fires in Ontario

2004-2007

Fatalities - 0

Injuries - 17

Before

After

Year2004

Fire Loss$30M

2005 $25M

2006 $34M

2007 $57M

Fire Safety

Ontario Association of Fire Chiefs state that “NFBC may not adequately address the fire safety risks...due to the following factors”.

Size – building access and water supply

Combustibles – building materials, biogas, etc.

Appliances – equipment, hydro and fuel

Unrestricted Fire Spread – large open areas and inadequate fire separations

Ignition Sources – lighting and heating equipment

Use – classification of large Farm Buildings

Fire Safety

Building Access and Water Supply

Access roads on all sides

On-site water supply if no hydrants

Fire Safety

Spatial Separation

No requirements for farm building to farm building

11,000+ m2 of building10m separation with 100% UPO

Fire Safety

Fire Separation

Firewalls to separate areas.

Maintain 4800 m2 maximum floor area

Fire Safety

Fire Stops – they do work

Continuity critical – doors, seal at steel deck

Perpendicular to trusses?

Fire Safety

OMAFRA & Ontario Technical Advisory Committee recently published “Reducing the Risk of Fire on Your Farm”.

Publication 837 examines the major causes of farm building fires and what can be done to reduce the risks.

Copies here and available through OMAFRA and Publication Ontario

Many images from this publication.

Fire Safety

OMAFRA & Ontario Technical Advisory Committee recently published “Reducing the Risk of Fire on Your Farm”.

Publication 837 examines the major causes of farm building fires and what can be done to reduce the risks.

Copies here and available through OMAFRA and Publication Ontario

Many images from this publication.

National Farm Building Code

National Farm Building Code 1995 governs farm building construction in Ontario

No updates since publication

Old design criteria and material standards

Ontario, BC & NS use NFBCC 1995

AL, MB, SK, QC, NB, NL & PEI use no farm building code

Manitoba has recently declared farm buildings to be F2/F3.

National Farm Building Code

The Canadian Commission on Building and Fire Codes has agreed to work on updating the requirements for large farm buildings with a view to incorporating these updates into the 2015 National Building and National Fire Codes. The new requirements will be objective- based to match the format of other reference documents.

Large farm buildings only.

Design and Construction of Large Farm Building

Questions