OSB Performance by DesignTM

Oriented Strand Boardin Wood Frame Construction

Canadian Edition 2004

WAIVER OF RESPONSIBILITYEvery effort has been taken to ensure that the information published inthis manual is accurate and as complete as possible. The StructuralBoard Association does not, however, assume responsibility for errors oromissions in this publication, nor for any designs or specifications basedon it. It is the specifier’s and/or user’s responsibility to obtain the necessary approvals and inspections from the local building officials.

© Copyright 2004 Structural Board Association

TM422 03M0804 ISBN 1-896479-02-2

Printed in Canada

ABOUT THIS MANUALThis Manual has been developed to provide the designer, specifier, builderand home buyer with as complete a source of information as possible on thespecification and use of oriented strand board (OSB). Now in its fourteenth printing, it has been completely revised to reflect recent code changes, newstandards, new information and new products. It also reflects the growth ofthe Structural Board Association as the leading voice of the OSB Industry.

ACKNOWLEDGEMENTSBA committed its technical resources and engaged the services of Quaile Engineering Ltd. andKwik Kopy Design & Print Centre. We would also like to acknowledge the participation of severalindustry reviewers who ensured the completeness of this manual. Cover photos courtesy ofCloverdale Truss Co. Ltd. (Surrey, BC) and Weyerhaeuser Canada Ltd. (Edmonton, AB).

Performance by DesignTM is a registered trademark of the Structural Board Association.

1.0 Introduction1.1 Oriented Strand Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11.2 Research Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

2.0 Manufacturing Process2.1 Basic Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22.2 Performance by Design™ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22.3 Quality Assurance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22.4 OSB and the Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

3.0 OSB Products3.1 Panel Sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43.2 OSB Conforming to CSA O325.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43.3 OSB Conforming to CSA O437.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43.4 U.S. Standard PS 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53.5 Panel Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

4.0 Properties4.1 Physical and Mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64.2 Other Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

5.0 Residential and Low Rise Commercial Installation5.1 Floor Sheathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105.1.1 Fastening for Floor Sheathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115.1.2 Finished Flooring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145.1.3 Concrete Topping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145.1.4 Hardwood Floors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145.1.5 Ceramic Tile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .155.1.6 Floor Vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .155.2 Floor Underlayment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .165.3 Roof Sheathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .175.3.1 Ventilation of Attic and Cathedral Roof Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 85.3.2 Prevention of Ice Damming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .185.3.3 Truss Uplift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .185.4 Wall Sheathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .195.5 Exterior Siding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .205.6 Moisture During Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .215.7 Detailing and Good Construction Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .215.8 Shipping Handling and Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .215.9 Maximum Loads for CSA O325 OSB Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

6.0 Other Uses for OSB6.1 Structural Insulated Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .226.2 Wood I-Joists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .226.2.1 Engineered Floor Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .226.3 Renovation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .226.4 Industrial Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .226.5 Engineering Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .236.6 Horizontal Diaphragms and Shearwalls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .236.7 OSB Panels over Metal Framing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

TABLE OF CONTENTS

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Figure 1 OSB Manufacturing Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Figure 2 OSB Lay-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Figure 3 Examples of Certification Marks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Figure 4 Floor Sheathing Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Figure 5 Floor Underlayment Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Figure 6 Roof Sheathing Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Figure 7 Wall Sheathing Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Figure 8 Exterior Siding Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Figure 9 Typical Structural Insulated Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Table 1 Basic Properties of CSA O437.0 OSB and Waferboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Table 2 Performance Requirements for CSA O325.0 and PS 2 OSB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Table 3 Minimum Nail Resistance Requirements for OSB Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Table 4 Physical Properties of OSB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Table 5 Fastening Schedule for OSB Sheathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Table 6 Nail Weight, Length and Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Table 7 Recommended Floor Sheathing for Hardwood Flooring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Table 8 Recommended Floor Sheathing Systems for Ceramic Tile Flooring . . . . . . . . . . . . . . . . . . . . . . . . .15

Table 9 Maximum Allowable Loads for Rated OSB Roof Sheathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Table 10 Factored Shear Resistance for OSB Shearwalls with S-P-F Framing . . . . . . . . . . . . . . . . . . . . . . . .23

Table 11 Factored Shear Resistance for OSB Diaphragms with S-P-F Framing . . . . . . . . . . . . . . . . . . . . . . .24

Appendix A Glossary of Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Appendix B SBA Member Plant Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

SBA Member Companies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

Associate, Allied and Research Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

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Oriented Strand Board (OSB) is a structural panel suitable for a wide range of construction and industrialapplications. It is a mat-formed panel made of strandssliced in the long direction from small diameter, fastgrowing round wood logs and bonded with an exterior-type binder under heat and pressure.

OSB’s predecessor random waferboard has been commercially available since 1962. OSB became available in 1981 and has now replaced waferboard.However, waferboard panels are still available from onemanufacturer in Canada. OSB and waferboard conforming to CSA Standard O437.0 is referenced by theNational Building Code of Canada (NBCC) and allprovincial codes. Grade O-2 OSB is specifically recognized by the NBCC as being structurally equivalentto plywood when used as roof, wall and floor sheathing.

The NBCC also references construction sheathing conforming to CSA Standard O325.0. These panels areperformance tested for use as subfloor, roof sheathingand wall sheathing. While any wood based materialmay be used to make construction sheathing, OSB iscommonly certified to CSA O325.

The OSB industry is well established and growing rapidly. To the end of 2003 the worldwide industry hadgrown to 77 mills (40 U.S., 24 Canadian, 13 offshore)with a combined production of 24 million cubic metres.Additional mills are under construction and in theplanning stage in the U.S., Canada and offshore. It isanticipated that by 2006 there will be 80 mills worldwide.

1.2 Research Program

Over the years the SBA has been a major participant i nthe direction, coordination and funding of a market driven research and development program. Its purpose is to enhance the OSB productsmanufactured by its members, as well as to optimize themanufacturing process. This program, conducted by analliance of reputed research organizations and universitiesin the U.S. and Canada, led to several achievementsincluding but not limited to: optimization of log yardmanagement and pressing operations, development ofOSB products with improved physical and mechanicalproperties, OSB product stewardship, process modeling,and development of OSB engineering properties.

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1.0 INTRODUCTION

1.1 Oriented Strand Board

2

Figure 1 illustrates the typical sequence in themanufacturing of OSB. OSB is made from aspen,poplar, southern yellow pine or other mixed hardwoodand softwood logs. The logs are debarked and cut toshorter lengths before being processed in the strander.The fines and bark become fuel for the mills energysystem.

The strander slices the logs into strands along thedirection of the grain. Strand dimensions arepredetermined for the process and have a uniformthickness. The majority of Association mills use acombination of strands ranging in length from 90 to 150 mm and approximately 25 mm wide.

The strands are then dried and sorted. Before forming,the strands are mixed with wax and a waterproofexterior-type binder (generally phenolic or isocyanateresin binder). These waterproof and boil-proof resinbinders will provide the panel with internal strength,rigidity and moisture resistance.

During forming the strands are oriented in layers. Thestrands on the panel surface are generally aligned in thelong direction of the panel for superior bending strengthand stiffness in this direction (see Figure 2). The two orthree inner layers are usually cross-aligned to thesurface layer like plywood. In waferboard the wafers areapproximately 25 mm x 45 mm and are randomly placedthroughout the panel.

After forming the mat of strands is pressed at a hightemperature and pressure to form a rigid, densestructural panel. OSB has considerable bending strengththat comes from the uninterrupted fibre, interweaving ofthe long strands and orientation of strands in the surfacelayers.

The panels are then cooled, cut to size, grade stamped,stacked in bundles and edge coated for shipping.

2.2 Performance by Design™

Oriented Strand Board structural wood panels are oftendesigned by the manufacturing process to meet specificend uses required by the customer. This flexibility inmanufacturing provides superior performance witheconomical cost to give excellent value to the end user.

2.3 Quality Assurance

The quality of OSB is the responsibility of the individualproducer. Each SBA mill has a program of in-plantquality control to ensure the finished product meets orexceeds the grade required in the applicable standardand the mill specification. Third party quality assuranceand audit programs back up the mill programs.

The SBA suggests that its producer members adopt a“Total Quality” concept. This starts with the cutting oftrees in the forest to the shipping of finished product fromthe mill to the customer’s satisfaction. State-of-the-artcomputer process control equipment, which is uniquelydesigned for each plant, greatly helps the implementationof in-mill quality control by monitoring and adjusting theprocess variables on a continuous basis. Plant qualitycontrol staff oversee the process monitoring, payingparticular attention to selection of logs by species, sizeand moisture content; strand geometry and thickness;strand moisture content after drying; consistent blendingof strands, resin binder and wax addition; uniformforming of the mat entering the press; the presstemperature, pressure, closing speed, density andthickness control.

2.0 MANUFACTURING PROCESS

2.1 Basic Steps

Figure 2 OSB Lay-up

(C) OSB with aligned faceand random core

(B) OSB with aligned faceand oriented core

(A) Random Waferboard

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Quality control personnel regularly inspect panel faces,edges, dimensions after trimming and the physicalappearance of the finished panel. They also undertakephysical testing of the panels according to standard testprocedures as necessary to verify that productionconforms to the applicable standard and millspecification. Besides company process and qualitycontrol, manufacturers grademarking to CSA O325 orexporting to the U.S. are required to have independentthird party inspection and testing to CSA O325.1 and /orthe U.S. Performance Standard PS 2 by an approvedcertification agency, another assurance that quality ismaintained.

2.4 OSB and the Environment

Oriented Strand Board is generally manufactured fromaspen in the northern part of North America andsouthern yellow pine in the south. However, otherhardwood and softwood species or combinations mayalso be used. Aspen and northern hardwoods areharvested from naturally regenerated self-sustainingstands. Southern yellow pine is harvested frommanaged private stands and includes thinnings. Themanufacturing process uses most of the log and modernmills typically convert the remaining bark, saw trim, andsawdust into energy.

Modern mills are scientifically designed to meet orexceed the strict quality standard for air emissions byusing collectors, precipitators, scrubbers or regenerativethermal oxidation units to remove particulate and volatileorganic compounds from the discharge gases releasedinto the atmosphere. Where log soaking ponds areused, the water is filtered and the ponds are selfcleaning. The mills are designed to be self sufficient interms of heat energy with all bark, screenings, sawdustand panel trim recycled as fuel for the dryer and thepress heating system.

Like construction plywood, OSB panels are bondedunder heat and pressure with phenol formaldehyde orisocyanate binders that become durable, insoluble heat-resistant polymers that resist age, moisture and chemicaldegradation. Regular tests confirm formaldehydeemissions from phenolic-bonded OSB panels arenonexistent or negligible. However, freshly sawn OSBmay have the distinctive odour of freshly cut wood of thesame species.

SBA also provides a generic Material Safety Data Sheet(MSDS) for OSB and waferboard, and other technicalinformation on the binder system. Manufacturers arealso required by WHMIS to issue statements about wooddust.

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3.0 OSB PRODUCTS

Performance based OSB panels are specifically engineeredfor floor, roof, and wall sheathing purposes in wood frameconstruction. Panels are available in 1220x2440 mm (4’x8’)sheets or cut to size dimensions. For industrial applicationslarger sizes up to 2440x7320 mm (8’x24’) are available byspecial order. Some new mills manufacture master panelsup to 3660x7320 mm (12’x24’) or other custom sizes.

3.2 OSB Conforming to CSA O325.0

CSA Standard O325.0 “Construction Sheathing” is aperformance based standard for floor, roof and wallsheathing. Panels installed on framing are evaluated forability to carry loads and resist deflection under loadingand conditions simulating or exceeding thoseexperienced in service and during construction. Thisstandard permits the use of panels to be of anythickness and made with either veneer or strands. Thecomponents must be bonded with phenol formaldehyderesin or an equivalent binder. The criteria foracceptance is the ability of the panels to perform, nothow they are made. This product requires third partycertification for conformance.

CSA O325.0 specifies rigorous performance tests forconcentrated and uniform static loads under wet and dryconditions. Impact tests are specified as well as fastenerholding capability. Physical properties of linearexpansion, thickness swelling, panel stability and bonddurability are also tested.

The ability of a product to meet the performancerequirements of a given end use is shown on the panelby a PANEL MARK . This panel mark consists of anend use mark followed by a span mark, eg. 1F16. Theend use markings are as follows:

Mark End Use1F Subfloor2F Subfloor used with panel-type underlay1R Roof sheathing without edge support2R Roof sheathing with edge support W Wall sheathing

The span mark indicates the maximum centre to centrespacing of the supporting members in inches. Thestandard marks are 16, 20, 24, 32, 40, and 48. Panelsmay qualify for more than one end use. For example, apanel may be marked 1R24/2F16/W24.

Part 9 of the NBCC uses the panel marks (notthicknesses) to show the minimum panels permitted forspecific end uses and spans. Construction sheathingpanels are also marketed according to the panel marks.Actual thicknesses determined during qualificationtesting are in steps of 0.5 mm and for a given span markcan vary slightly between manufacturers (a thin, strongpanel may perform better than a thick, weaker, less stiff,panel).

3.3 OSB Conforming to CSA O437.0

CSA Standard O437.0 “OSB and Waferboard” is aproduct standard that prescribes the minimummechanical and physical properties that the panels musthave. Conformance to this standard is done by in-milltesting to CSA O437 by mill personnel. In-mill tests canbe verified by third party testing if desired by the user.

This standard contains three grades. Grade R-1 iswaferboard, which is being phased out. Grades O-1 andO-2 are OSB panels. The NBCC specifies the use ofOSB based on grade and panel thickness.

The O-2 grade thicknesses are a soft conversion ofstandard imperial sizes. The O-1 and R-1 thicknessesare a hard conversion (see table below). Other panelthicknesses including 22.0 mm, 28.5 mm and 32.0 mmare available on special order. Panels 15.0 mm andthicker are manufactured either square-edged or tongueand grooved on the long edge. Most mills producepanels with textured surface treatments for improvedtraction on sloping roofs. Regular panels are eitherunsanded or touch sanded, however the product may beordered smooth sanded on one or both sides forindustrial or decorative uses.

3.1 Panel Sizes

The nominal thicknesses of CSA O437.0 OSB and waferboard are as follows:

Grade O-2 (mm) 6.0 7.5 9.5 11.0 12.0 12.5 15.0 15.5 18.0 19.0

Grade O-1, R-1 (mm) 6.35 7.9 9.5 11.1 – 12.7 – 15.9 – 19.0

Imperial (in.) 1/4 5/16 3/8 7/16 15/32 1/2 19/32 5/8 23/32 3/4

5

SBA members’ OSB production is generally intended foruse in both the United States and Canada. As a resultOSB panels are typically manufactured to meet both theU.S. Department of Commerce Voluntary PerformanceStandard PS 2 “Performance Standard for Wood BasedStructural Use Panels” and CSA Standard O325.0“Construction Sheathing”. PS 2 was a joint developmentof the U.S. and Canadian wood panel industry toharmonize the performance standards under theU.S./Canada Free Trade Agreement. The standard waspromulgated by the U.S. Congress in August 1992. Asecond edition is due for publication in 2004.

As shown in Table 2 the performance requirements of PS 2 and CSA O325.0 are quite similar. PS 2 has higherstrength requirements for wall sheathing and alsoincludes racking tests for wall and roof panels when usedas shearwalls or diaphragms.

The span ratings shown on the PS 2 OSB panel markingsconsist of two numbers separated by a slash e.g. 24/16.The left-hand number shows the maximum supportspacing for roof sheathing and the right-hand numbergives the maximum support spacing for floor sheathing ininches. PS 2 panels for single floors (combinationsubfloor and underlayment) have a single numberfollowed by the letters OC e.g. 20 OC. This means themaximum support spacing is 20 inches (500 mm) oncentre and edge blocking or tongue and groove edgesare required.

3.5 Panel Marking

CSA O325.0 panels are required to be marked with thefollowing information (see Figure 3 for examples):

- The manufacturer’s name or logo and Mill Number- The designation CSA O325.0- The panel mark denoting the span rating and end use- The nominal thickness in mm (inch equivalents may

also be shown)- The direction of face alignment- The date code- The certification agency logo- The words Exterior Bond or Exterior Type Binder

Some panels may have more than one mark. Forinstance some panels are certified to CSA O325.0 andPS 2, in which case the panel mark will containinformation required by both standards.

CSA Standard O437.0 requires that all OSB andwaferboard panels made in conformance with thisstandard be clearly marked with the following information:

- The manufacturer’s name or logo and Mill Number- The designation CSA O437.0- The words Exterior Bond or EXT. BOND- The appropriate grade mark R-1, O-1, O-2- The nominal thickness in mm- The direction of orientation if O-1 or O-2 grade- THIS SIDE DOWN on the back of T and G panels

Panels manufactured to CSA O437 may have edge andend defects that can be eliminated by cutting back thepanel so that the remaining panel size meets therequirements of the standard. These panels are markedSHOP PANELS and are suitable for many uses in thereduced size. SBA member mills provide 2.6 squaremetres of usable panel in each shop panel.

Panels not meeting the requirements of either CSAstandard or the U.S. Standard are marked REJECT - ALLOTHER MARKS VOID. These panels are not suitable forbuilding construction.

Panels manufactured for export sale are also marked withstamps required by the importing country. In addition,each panel must be marked with Made in Canada eitheron the face or edge.

3.4 U.S. Standard PS 2

Figure 3 Examples of Certification Marks

4.0 PROPERTIES

Grade O-2 Grade O-1 Grade R-13

Metric Imperial Metric Imperial Metric Imperial

Dimensional tolerances, dry, as shipped2

• Length and width, from stated dimensions +0, +0, +0, +0, +0, +0,-4 mm -5/32” -4 mm -5/32” -4 mm -5/32”

• Squareness, maximum difference in diagonals 4 mm 5/32” 4 mm 5/32” 4 mm 5/32”

• Straightness, maximum deviation from straight 1.5 mm/ 1/16”/ 1.5 mm/ 1/16”/ 1.5 mm/ 1/16”/edge edge edge edge edge edge

• Thickness2

• panel average from nominal ±0.75 mm ±0.030” ±0.75 mm ±0.030” ±0.75 mm ±0.030”• within panel from panel average ±0.75 mm ±0.030” ±0.75 mm ±0.030” ±0.75 mm ±0.030”

Mechanical properties, dry, as shipped4

• Modulus of rupture - parallel 29.0 MPa 4200 psi 23.4 MPa 3400 psi 17.2 MPa 2500 psi

• Modulus of rupture - perpendicular 12.4 MPa 1800 psi 9.6 MPa 1400 psi 17.2 MPa 2500 psi

• Modulus of elasticity - parallel 5500 MPa 800,000 psi 4500 MPa 650,000 psi 3100 MPa 450,000 psi

• Modulus of elasticity - perpendicular 1500 MPa 225,000 psi 1300 MPa 190,000 psi 3100 MPa 450,000 psi

• Internal bond 0.345 MPa 50 psi 0.345 MPa 50 psi 0.345 MPa 50 psi

• Lateral nail resistance (t = thickness 70t (N) 400t (lb) 70t (N) 400t (lb) 70t (N) 400t (lb)of panel, mm or inches as appropriate)

Properties Following Moisture Exposure4

• Modulus of rupture - parallel - after 2 hr boil 14.5 MPa 2100 psi 11.7 MPa 1700 psi 8.6 MPa 1250 psi

• Modulus of rupture - perp - after 2 hr boil 6.2 MPa 900 psi 4.8 MPa 700 psi 8.6 MPa 1250 psi

• Thickness swell, after 24 hr soak, maximum• 12.7 mm and thinner 15% 15% 15% 15% 15% 15%• thicker than 12.7 mm 10% 10% 10% 10% 10% 10%

• Linear expansion, oven dry to saturated, maximum• parallel 0.35% 0.35% 0.35% 0.35% 0.40% 0.40%• perpendicular 0.50% 0.50% 0.50% 0.50% 0.40% 0.40%

OSB is manufactured with aligned strands in the longdirection on both panel faces. The alignment of strandsgives OSB panels improved strength in the long paneldirection. Direction of application is marked on thesepanels. Waferboard panels with randomly placed wafershave approximately equal strength and stiffness in alldirections in the plane of the panel and may be installed

in either direction across the supports.

The minimum physical and mechanical properties ofproducts conforming to CSA O437.0 are shown in Table 1.Table 2 lists the performance requirements of OSBproduced to CSA O325.0 and U.S. standard PS 2 andTable 3 contains the nail resistance requirements.

Table 1. Basic Properties of CSA O437.0 OSB and Waferboard1

Notes:1. Minimum requirements (maximum where stated) are based on a 5-panel average, with no single panel more than 20% below (or above as

appropriate) the stated requirement.2. Tolerances are for rough/sized boards. Tolerances for sanded panels are ±0.40mm for variation from nominal, and ±0.25mm for within panel

variation from panel average.3. Grade R-1 is for waferboard, which is only produced by one Canadian mill.4. These values are not for design purposes.

4.1 Physical and Mechanical

6

7

Notes:1. Tolerance is -0.5 mm to +1.0 mm if minimum thickness < nominal thickness, -0 to +1.5 mm if minimum thickness = nominal thickness.2. Span is the centre to centre spacing of supports.3. Requirements are minimum except where noted otherwise.4. These values are not for design purposes.5. In PS 2, for 1200 mm spacing, panels are performance tested at 3.83 kPa loading.

Property3 CSA O325.0 PS 2Metric Imperial Metric Imperial

• Thickness tolerance, panels ≤ 13/16” (20.5 mm) 1.5 mm range1 1/16” range1 ± 0.80 mm ± 1/32”panels > 13/16” (20.5 mm) 1.5 mm range1 1/16” range1 5% of the thickness

• Length and width tolerance, from stated dimensions +0, -4 mm +0”, -5/32” +0, -3.2 mm +0”, -1/8”

• Squareness tolerance, maximum deviationfrom square along diagonal 4 mm 5/32” 1.3 mm/m 1/64”/ft

• Straightness tolerance, maximum deviation from straight 1.5 mm 1/16” 1.6 mm 1/16”(corner to corner)

• Ultimate concentrated load• roof - static 1.78 kN 400 lb 1.78 kN 400 lb

- following impact 1.33 kN 300 lb 1.33 kN 300 lb

• subfloor - static 1.78 kN 400 lb 1.78 kN 400 lb- following impact 1.78 kN 400 lb 1.78 kN 400 lb

• combined subfloor/underlayment to 24” spacing

- static 2.45 kN 550 lb 2.45 kN 550 lb- following impact 1.78 kN 400 lb 1.78 kN 400 lb

• combined subfloor/underlayment 32” to 48” spacing

- static 3.12 kN 700 lb 3.12 kN 700 lb- following impact 1.78 kN 400 lb 1.78 kN 400 lb

• Maximum deflection under 0.89 kN load varies with application varies with application

• Ultimate uniformly distributed load• roof 7.2 kPa 150 psf 7.2 kPa 150 psf• floor - to 32” spacing 15.8 kPa 330 psf 15.8 kPa 330 psf

- 48” spacing 10.8 kPa 225 psf 10.8 kPa 225 psf• wall no requirements 3.6 kPa 75 psf

• Maximum deflection under uniform load2

• roof - 1.68 kPa load span/240 span/240 span/240 span/240• floor - 4.79 kPa load5 span/360 span/360 span/360 span/360

• Linear expansion, maximum • one sided wetting or 0.30% along major axis 0.30% along major axis

50% to 90% relative humidity exposure 0.35% across major axis 0.35% across major axis

• 50% R.H. to vacuum pressure soak 0.50% 0.50% 0.50% 0.50%

• Thickness swell, maximum • one sided wetting after 14 day exposure, or 25% 25% 25% 25%

R.H. exposure (Single Floor only) (Single Floor only)

• Bond durability (minimum modulus of rupture)4

• six cycle test 50% strength retention 50% strength retention• 2 hour boil 50% strength retention N/A• single cycle test N/A See table 6 of PS 2

Table 2. Performance Requirements for CSA O325.0 and PS 2 OSB

8

Other properties of OSB may be summarized as follows:

WorkabilityOSB is easy to saw, drill, nail, plane, file or sand. Itcontains wood, fully cured waterproof and boil proof resinadhesive and a small amount of wax. Use normalcarpentry tools, but carbide tipped blades arerecommended for prolonged use. Wear appropriatesafety protection and follow safe working procedures. As wood dust has been designated as a potentialcarcinogen, avoid exposure to airborne dust particlesand keep work areas free of dust build-up. A materialSafety Data Sheet is available from the SBA officecovering wood dust.

As full-size panels have a factory applied edge coating,job cut panels likely to be exposed to the weather shouldhave uncoated edges protected by a field coat of paint orby sheathing paper to reduce moisture pick-up.

NailabilityThe many interleaved layers create panels with good nailholding properties. Nails can be driven as close as 6mmfrom the panel edges without risk of splitting or breakingout. However, the Association recommends an edgedistance of 10mm for structural applications. Extensivetests undertaken by research establishments showfastener performance is similar for all structural woodpanels. In addition both CSA O437.0 and CSA O325.0specify minimum nail holding capability for OSB. Whenusing power actuated nailers do not overdrive nails,make sure eye protection is worn and follow safeworking procedures.

GluabilityOSB may be glued with any adhesive recommended forwood. For strong bonds, lightly sand the surfaces in theareas to be glued. For more information on glued jointscontact the SBA office.

PaintabilityOSB may be finished with any good quality paint systemrecommended for wood. For best results the surfacemust be primed or sealed before painting.

For exterior applications, the best finish is a good qualityexterior wood paint system (primer and top coat) appliedaccording to the paint manufacturer’s directions. Solidcolour paints provide the best weather protection for thepanel surface and the strands show a pleasing texture.A top quality acrylic latex exterior paint and companionprimer specifically designated by the manufacturer as‘stain blocking’ or ‘stain resistant’ are recommended.

OSB also takes all kinds of stain finishes as well.However, stains do not offer as much surface protectionfrom the weather as paints and the lifting of anoccasional strand may occur. Stains are more oftenapplied to fences, summer cottages and otherapplications that accept a more rustic appearance.

Sanded panels present a marble-like appearance andthey are less textured than unsanded panels. Asvarnishes, stains and paints penetrate the sanded panelsmore quickly than the unsanded, two coats of primer orsealer are recommended before application of the finishsystem. When applying paint or varnish, sand thesurfaces lightly between coats; do not sand stainedsurfaces.

WeightThe approximate weight of OSB panels can becalculated from Table 4. These values are based on adensity of 640kg/m3 (40 lb/ft3). Density may varydepending on the manufacturer and moisture conditionsat the time of shipment.

Thermal ResistanceThe thermal resistance of a material is a measure of theresistance it offers to the passage of conducted heat at asteady rate. It is proportional to the density andthickness of the material. Table 4 provides thermalresistance values for various thicknesses of OSB.

PermeabilityThe permeability of a wood panel is the rate thatmoisture passes through the panel under statedconditions of moisture vapour pressure. It is inverselyproportional to the density, degree of orientation andthickness of the panel. Vapour permeance values forOSB panels are given in Table 4.

Fire PerformanceOSB has been tested to determine fire endurance andflame spread ratings by both SBA and APA. These testshave been undertaken by third party agencies usingrecognized fire test laboratories. The test results showthat OSB panels, like plywood, may be used as exteriorsheathing on outside walls required to have a fire rating.However, code authorities may require that stud spacesbe filled with non-combustible insulation such as rockwool when structural wood panels are used on thesewalls. Structural wood panels are permitted to beinstalled between the framing and the fire-resistivecovering in walls provided the length of the fastener usedto attach the fire protection is increased by an amount atleast equal to the thickness of the wood panel.

4.2 Other Properties

9

Moisture PerformanceOSB like all wood products reacts to changes in moisture and humidity conditions. OSB is required by NorthAmerican Standards to maintain its strength and stiffnessperformance under normal humidity conditions, alsoreferred to as “standard conditions”, which are

represented by a temperature of 20 degrees Celsius and65 percent relative humidity. This condition is typical ofprotected construction. In addition, OSB is required tomaintain its strength and stiffness performance whenexposed to weather during long construction delays.

Nominal Weight Thermal Vapour Flame Smokepanel resistance permeance Spread Developed

thickness (mm) (N/m2) (m2 °C/w) (ng/(Pa•s•m2)) Rating1 Index1

9.5 60 0.08 145 148 137

11.0 69 0.09 120 148 137

12.5 79 0.11 85 148 137

15.5 97 0.13 65 148 137

18.5 116 0.16 652 148 137

Table 4. Physical Properties of OSB

Table 3. Minimum Nail Resistance Requirements for OSB Panels1 , 2

Notes:1. These numbers are average test values obtained by APA, The Engineered Wood Association on several thicknesses of OSB.2. Panel thicknesses greater than 15.5 mm were not tested, but can be assumed to provide a permeability resistance equal to or better than that of

15.5 mm panels. Vapour permeance values are given for 50% relative humidity (R.H)., and increase slightly with increasing R.H.

Notes:1. Nails are 51mm for sheathing less than or equal to 12.7mm, 63mm for thicker panels.2 . Comparison studies (University of Illinois) have shown the equivalent performance of OSB and plywood in lateral and withdrawal resistance of nails.3. These values are not for design purposes. Additional information regarding shearwalls and diaphragms is given in Tables 10 & 11.4. Not applicable for wall sheathing.

CSA O325.0 PS 2Loading Application Minimum ultimate load (N)3 Minimum ultimate load (N)3

Dry Wet / Redry Dry Wet / Redry

Lateral roof and wall sheathing 534 400 534 400

subfloors and single floors 934 712 934 712

Withdrawal all sheathing 89 67 894 674

10

The following sections present installation instructions forOSB sheathing in residential and low rise commercialconstruction. The information is based on Part 9 of theNBCC and is generally applicable to the provincialbuilding codes.

5.1 Floor Sheathing

Figure 4 provides the recommended installation detailsfor floor sheathing along with the maximum supportspacing for the various grades.

The 2F sheathing is intended to have an additional layerof structural material such as an underlayment panel,wood strip flooring applied at right angles to the joists, orconcrete topping. The 1F sheathing panels are used as

combination subfloor and underlayment and do notrequire an additional layer. The edges of all panels musthave tongue and groove joints or be supported with38x38 mm blocking securely nailed between framingmembers.

Panels must be installed with the direction of face grainat right angles to the joists (OSB panels have the facegrain direction marked on the panel). They should belaid across three or more supports keeping the sidemarked “this side down” on the supports when usingT&G panels. End joints must be made over the supportsand should be staggered at least two supports. Subfloorsheathing panels should have a 3 mm (1/8”) gap on allsides and ends.

5.0 RESIDENTIAL AND LOW RISE COMMERCIAL INSTALLATION

Subfloors: Leave a 3 mm (1/8”)minimum gap.

Stagger panelend joints

T & G panels applied acrosssupports, with mark This SideDown, placed down. All panelsare to be continuous over 2 ormore spans

Joists or TrussesNote: In crawl spacesprovide adequateventilation and coverground with moisturebarrier.

Notes:1. Permitted with wood panel underlayment or concrete topping except when finished flooring consists of ceramic tile applied with an adhesive.2. Panels shall have tongue and groove edges or have edges blocked by minimum 38x38 mm blocking securely nailed between framing members.3. Some jurisdictions allow 22.5 mm (7/8”) thick O-2 grade panels on 800 mm (32”) joist spacing. These panels are marked 1F32.4. If OSB subfloor is flooded due to ponding, it is recommended that several holes be drilled in pond area so that water will drain from floor.5. For hardwood flooring recommendations refer to Section 5.1.4

Subfloor RequirementsCSA O437.0 OSB/Waferboard

Minimum thickness

Maximum NominalJoist spacing O-2 O-1/R-1 Imperial

400 mm - 16” 15.5 mm 15.9 mm 5/8”

500 mm - 20” 15.5 mm 15.9 mm 5/8”

600 mm - 24” 18.5 mm 19.0 mm 3/4”

400 mm - 16” 12.5 mm1 12.7 mm1 1/2”

CSA O325.0 OSBMinimum Panel Mark

Combined With panel typesubfloor/underlayment underlayment

1F16 2F16

1F20 2F20

1F24 2F24

Blocking ifsquare edgepanel

Figure 4 Floor Sheathing Installation

11

Table 5 contains the recommended fastening methods forOSB floor sheathing. Standard nail sizes and lengths aregiven in Table 6. For improved performance SBArecommends the use of wood screws rather than nails.

The performance of any floor system can be enhanced, ifin addition to the normal nailing, the sheathing panel isglued to the supporting joists with an elastomericadhesive and the tongue and groove edges gluedtogether. The glue creates composite action between the

joists and the sheathing, which stiffens the floor andreduces vibration. In fact, many new engineered floor joistproducts such as I-joists can be installed on longer spanswhen the subfloor is glued. Use elastomeric gluesconforming to CGSB Standard 71.26-M88 or ASTMstandard D3498. Special attention should be given to theconnection between the bottom plate of non-load bearingpartition walls and the subfloor panel. SBA recommendsthat the subfloor be screwed to the bottom plate of the wall.

5.1.1 Fastening for Floor Sheathing

MinimumPanel thickness Fastener Length1 Number and Location2,3,4

20 mm thick or less - 51 mm (2”) spiral nail, 150 mm (6”) oc at panel edges- 45 mm (1-3/4”) ring 300 mm (12”) o/c along intermediate supports

thread nails or screws 5,- or 51 mm (1-1/2) staples6

Greater than 20 mm thick - 57 mm (2-1/4”) spiral nail, 150 mm (6”) oc at panel edges- 51 mm (2”) ring thread 300 mm (12”) o/c along intermediate supports

nails or screws5

Table 5. Fastening Schedule for OSB Sheathing

Notes:1 . Common nails conforming to CSA B111 “Wire Nails, Spikes and Staples” are permitted in place of spiral nails, but generally have less withdrawal

resistance. For power driven nails or staples used in all types of building construction, consult NER 272 issued by ICC–ES to ISANTA (www.icc-es.org).2 . Nails should be 10 mm (3/8”) minimum from panel edge.3 . Other equivalent fastening schedules may be used.4 . In high wind areas closer spacing may be necessary to offset wind uplift forces.5 . Flooring screws shall be not less than 3.2 mm in diameter, and should conform to ANSI B18.6.1 “Slotted and Recessed Wood Screws”.6 . Staples can be 38 mm long for OSB panels up to 10 mm thick.

Table 6. Nail Weight, Length and Gauge

Sizes of common wire nailsLength Diameter No. per(mm) (inches) (mm) (inches) pound

38 1-1/2 2.34 0.092 32251 2 2.84 0.112 16757 2-1/4 2.95 0.116 14163 2-1/2 3.25 0.128 10476 3 3.66 0.144 6782 3-1/4 3.66 0.144 6389 3-1/2 4.47 0.176 47

101 4 4.88 0.192 25

Sizes of ardox spiral underlay flooring nailsLength Diameter No. per(mm) (inches) (mm) (inches) pound

25 1 2.34 0.092 51832 1-1/4 2.34 0.092 47338 1-1/2 2.34 0.092 40044 1-3/4 2.64 0.104 27951 2 2.64 0.104 240

Ringed thread subflooring nailsLength Diameter No. per(mm) (inches) (mm) (inches) pound

44 1-3/4 2.64 0.104 175

Log Hauling and Sorting Jackladder

Blending

Forming Line Pressing

Figure 1 OSB Manufacturing Process

Drying

12

Debarking

Stranding

Finishing Line Shipping 13

Wet Bins

14

After the building is closed in and heated and just beforelaying the finished floors, sweep and vacuum the panels.Carefully check the floor surface for protruding nail headsand make sure all panels are fully nailed. Adversemoisture conditions may have caused some panel edgeswelling. Sand panel edges flush and ensure panels aredry before installing the finished floor. If the sheathingwas subjected to severe moisture conditions duringconstruction it may be necessary to level the entiresurface with a light sanding.

Carpet and felted-synthetic-fibre flooring may be installedon top of the panels following good practice and theflooring manufacturers directions. For resilient flooringsand adhesive applied ceramic tile use a panel typeunderlayment. SBA also recommends that underlaymentbe used under wood parquet flooring.

5.1.3 Concrete Topping over OSB Subfloors

Concrete toppings are often used over panel subfloors toincrease the sound insulation properties and fireresistance of the floor system. Light-weight gypsumconcrete manufacturers typically recommend using 19 mm of concrete poured directly over 18.0 mm (1F24)tongue and groove subfloor with the joists spaced at 400to 600 mm on centre. However, 19 mm of concrete over15.0 mm (1F20) subfloor with joists at 500 mm on centre,or 25 mm of concrete for joists at 600 mm on centre, isoften acceptable to local building officials. The subfloorshould be clean and free of contaminants beforeapplication.

5.1.4 Hardwood Floors

The National Wood Flooring Association (NWFA), theNational Oak Flooring Manufacturers Association(NOFMA) and major hardwood flooring manufacturersrecognize the use of 18.0 mm or thicker OSB subfloormeeting PS 2 under hardwood flooring. Recommended

support spacings for OSB meeting Canadian standardsare shown in Table 7. The subfloor should be glued andnailed to the framing and the tongue and groove or panelblocked edges should also be glued. The thick panelprovides good nail holding power and the reducedsupport spacings along with the gluing will create a stifffloor that will help reduce floor squeaks after hardwoodfloor installation.

It is important that the subfloor be dry when thehardwood is installed, otherwise buckling and squeakingof the hardwood floor will occur when the subfloor driesout. Should it become wet during construction it must bedried out and the moisture content checked with amoisture meter to assure that it is within limits acceptableto the hardwood manufacturer.

The subfloor should be level, especially the jointsbetween panels. Any ridges at panel edges should besanded smooth before hardwood installation using aheavy-duty floor sander and a moderately coarse gritsandpaper. Following sanding, any areas of the floorthat squeak should be renailed.

For handling, storing and acclimatizing the hardwoodflooring, follow the recommendations of the manufactureror NOFMA, NWFA or MFMA. Where possible, orient thehardwood strips perpendicular to the floor framing andnail into the joists for best results.

5.1.2 Finished Flooring over CombinationSubfloor and Underlayment

Table 7. Recommended Floor Sheathing for Hardwood Flooring

Support Minimum thickness of Minimum panel mark forspacing CSA O437.0 OSB CSA O325.0 OSB1

300 mm - 12” 18.0 mm - 23/32” 1F20 or 2F20

500 mm - 20” 18.0 mm - 23/32” 1F24 or 2F24

600 mm - 24” 22.5 mm - 7/8” 1F32

Note: 1. 18.0 mm (23/32”) thick panels are recommended for best performance.

15

Table 8 provides the minimum recommended floorsheathing systems for ceramic or other tiles. For goodperformance it is important that the floor system be asstiff as possible. Therefore, the use of thicker subfloor(i.e. 18.0 mm or 1F24) or underlayment along withreduced fastener spacing will enhance the performance

of the floor. Some jurisdictions require blocking betweenthe floor joists in high traffic areas when ceramic tile isinstalled over OSB or plywood. Prohibit traffic on the tileuntil the mortar or adhesive has set in order to avoidcracking.

5.1.5 Ceramic Tile

The span tables for sawn lumber floor joists given in Part9 of the NBCC have been developed considering floorvibration or “bounciness”. The procedure for calculatingthe vibration controlled span is given in the appendix ofthe NBCC. This procedure recognizes that floor

bounciness is reduced when thicker subfloor is used andwhen the subfloor is glued and nailed (or screwed) to thejoists. The Canadian Wood Council’s Span Bookincludes floor joist span tables for 15.5 mm and 18.5 mmsubfloors either nailed or glued and nailed to the joists.

5.1.6 Floor Vibration

Minimum Subfloor

Panel Thickness3 Underlayment Tile Installation

15.5 mm (5/8”) minimum 11.0 mm (7/16”) CBU4,5 Dry-Set mortar or latex-portland cement mortar

15.5 mm (5/8”) none Cement mortar (32 mm)7

15.5 mm (5/8”) 11.0 mm (7/16”)8 Organic adhesive

15.5 mm (5/8”) 12.0 mm (15/32”)6,8 Epoxy mortar

Table 8. Recommended Floor Sheathing Systems for Ceramic Tile Flooring 1,2

Notes:1. Based on ANSI Standard A108, specifications of the Tile Council of America, and NBCC.2. Joist spacing not to exceed 400 mm (16”) oc. Joists should be blocked with solid blocking on 100 mm (4”) centres in high traffic areas.3. Provide edge support for subfloor.4. Bond cementitious backer units (CBUs) to subfloor with latex - Portland Cement or epoxy mortar prior to spreading mortar for setting ceramic or other tile.5. Leave 3 mm (1/8”) space at panel ends and edges. Fill joists with mortar.6. Leave 6 mm (1/4”) space at panel ends and edges; trim panels as necessary to maintain end spacing and panel support on framing. Fill joints with

epoxy mortar when it is spread for setting tile. With single layer subfloor use solid blocking under all panel ends and edge joints, including tongue and groove joints.

7. Use No.15 asphalt felt or 4-mil polyethylene sheeting over subfloor. Reinforce mortar with wire mesh.8. Underlayment or Exterior grade plywood.

16

When fastening, begin atcontact corner and workdiagonally across panel

Offset paneledge joints onejoist space fromsubfloor paneljoints

Minimum 6 mm (1/4”) spacearound room perimeter

Butt edges into lightcontact

Offset panel joints200 mm (8”) minimum

Space fasteners 12mm (1/2”) minimumfrom panel edge

Sanded OSBunderlayment

Fastener Size & Type

Nail Staple

Size/Type Shank Diameter Length Crown Width

6 mm - 1/4” 19 mm (3/4”) annular grooved 1.2 mm 22 mm 4.7 mmflooring nails or spiral nails (0.047”) (7/8”) (3/16”)

7.5 mm - 5/16” 22 mm (7/8”) annular grooved 1.2 mm 28 mm 4.7 mmflooring nails or spiral nails (0.047”) (1 1/8)” (3/16”)

Sanded

OSB

Panel Thickness

Figure 5 provides the recommended installation details forOSB floor underlayment along with fastener size and type.Sanded 6 mm or greater OSB floor underlayment issuitable for use under many finished flooring productssuch as: felted-synthetic-fibre or carpet; embossedresilient flooring; perimeter glued or loose lay resilientflooring. For adhesive applied ceramic tile theunderlayment must be no less than 11 mm thick if thesupports are spaced more than 300 mm apart.

Before applying the underlayment thoroughly sweep orvacuum clean the subfloor. Reset all popped nails and re-nail any loose panels. When underlayment is applied overpanel subfloors, apply the panels immediately prior to

installation of the finished flooring. When underlaymentpanels are applied over lumber board subfloors, applypanels parallel to joists if boards are perpendicular tojoists. Underlayment panels may be applied in eitherdirection if boards are at an angle less than 75° to joists.

To fasten, begin nailing or stapling at contact corner ofunderlayment panels and work diagonally across panels.Make sure the panels are in firm contact with the subfloorwhen driving the fasteners. Space nails at 100 mm oc onpanel edges, and 200 mm oc in the centre of the panel.Or use staples at 75 mm oc on panel edges, and 150 mmoc elsewhere. When gluing underlayment to subfloor useonly solvent based glues.

5.2 Floor Underlayment

Figure 5 Floor Underlayment Installation

17

Roof Sheathing Requirements

CSA O437.0 OSB/Waferboard1 CSA O325.0 OSBMinimum thickness Minimum Panel Mark

Maximum truss, Edges Edges Edges Edgesjoist or rafter Supported2 Unsupported Supported2 Unsupported

spacing O-2 O-1/R-1 O-2 O-1/R-1

300 mm - 12” 7.5 mm - 5/16” 9.5 mm - 3/8” 7.5 mm - 5/16” 9.5 mm - 3/8” 2R16 1R16

400 mm - 16” 7.5 mm3 - 5/16” 9.5 mm - 3/8” 9.5 mm - 3/8” 11.1 mm - 7/16” 2R16 1R16

500 mm - 20” 9.5 mm3 - 3/8” 11.1 mm - 7/16” 12.5 mm - 1/2” 12.7 mm - 1/2” 2R20 1R20

600 mm - 24” 9.5 mm3 - 3/8” 11.1 mm - 7/16” 12.5 mm - 1/2” 12.7 mm - 1/2” 2R24 1R24

5.3 Roof Sheathing

Notes:1. Panel thicknesses and marks apply for pitched roofs; where flat roofs are used as walking decks, the requirements for floors shall apply.2. Panel edges supported by 38x38 mm blocking, metal H-clips at midspan between framing members, or have tongue and groove edges.3. For enhanced performance SBA recommends using 9.5 mm in place of 7.5 mm and 11 mm in place of 9.5 mm sheathing.4. Panels to be minimum 600 mm wide and continuous over two or more spans.

Figure 6 provides the recommended installation details forroof sheathing along with the maximum support spacing.

Before installing the sheathing, the rafters or upper trusschord should be checked to assure that they are aligned,straight and even. Curved or uneven rafters or upper trusschords affect the finished roof appearance.

The panels should be installed textured side up with theirlong direction across the rafters or truss chords. Longpanel edges should be supported or joined with edge clipswhere required. A 3 mm (1/8”) gap should be left at the

panel edges and ends to allow for movement due tochanges in humidity. Panels should be staggered at leasttwo supports and end joints must lie over supports.

Table 5 contains the recommended fastening methods forOSB roof sheathing. The installer should stand over therafter or truss when nailing. Safety Alert: As roofsheathing may be slippery when wet, covered with frost,snow, ice, or sawdust, installers should wear rubber soledfootwear, use appropriate safety equipment and useextreme caution when working on sloping roofs.

Stagger panel end joints

Apply panels across supportsAll panels are to be continuous across two or more spans

Supports – Rafters, Trusses or Joists

Warning: Roof sheathing panels may be extremely slippery when wet, covered with frost, snow, ice or sawdust. Installers of roof sheathing shouldwear rubber-soled footwear and exercise caution, especially on roof slopes exceeding 4 in 12. Based on recent studies, soles of thermoplasticrubber provide the best traction of the sole materials tested. Place screened surface of panel face up.Note: Panels that get wet should be allowed to surface dry before applying shingles. Protect uncoated edges from direct rain exposure.

Leave a 3 mm (1/8”) minimum gap on alledges

Edge clips if specified

Support panel edges at ridge

Figure 6 Roof Sheathing

18

5.3.1 Ventilation of Attic andCathedral Roof Spaces

In order to minimize the impact ofmoisture build-up in attic spaces, it isessential that adequate ventilation beinstalled with 50% of the ventilation atthe roof ridge and 50% at the soffitarea. The NBCC specifies that theminimum unobstructed vent area equalnot less than 1/300 of the totalinsulated ceiling area for roofs with atticspaces. For roof slopes of less than 1in 6 or for cathedral ceilings, the freevent area must equal not less than1/150 of the insulated area.

In roofs without attic spaces (iecathedral ceilings) the NBCC requiresthat 38x38 mm cross purlins beinstalled over the joists and that therebe at least a 25 mm space between theinsulation and the top of the joist forventilation. For higher slopes the crosspurlins may be omitted provided theroof joists run up the slope with at least75 mm clearance between the top ofthe insulation and the top of the joist.

The roof should be dry prior to shingling and should beshingled as soon as possible after installation ofsheathing. Use baffles to make sure that the insulationdoes not block ventilation openings especially along theeaves and between truss chords. Ensure the attic hatchis sealed and bathroom or kitchen fan exhaust ducts areproperly vented to the outside. Inadequte ventilation canbe a cause of sheathing panel telegraphing through theshingles on cold winter days.

5.3.2 Prevention of Ice Damming

Ice damming occurs in extreme cold climates and is dueto heat transfer from the attic space to the shinglesmelting the snow during the day time period. At night,the snow melt freezes. Repeated cycles of freeze/thawcause a ridge of ice trapping the snow melt as it flowsdown the roof. The snow melt backs up under shinglesand soaks the sheathing. Rain storms can also threatenthe integrity of sloped roofs. The effect of ice dams andwind driven rain can be substantial from stained walls orceilings to severe water damage. A continuous

underlayment of ice and water self-adhering protectivemembrane or other heavy waterproofing material mustbe installed from the edge of the exterior wall 900 mm upthe roof under the shingles to protect the roof sheathingand in all other critical zones where roof leaks commonlyoccur (consult with membrane manufacturer for properinstallation).

5.3.3 Truss UpliftTruss uplift is a cause of ceiling/wall separation. Theceiling lifts as the truss arches away from the interiorpartition. Wood in prefabricated trusses shrinks as itdries and expands when it absorbs moisture. Since thebottom chord of the truss is buried in the attic insulation,it is warmer and therefore drier than the rest of the truss.The top chord is exposed to the damp attic air and willbe at a higher moisture content than the bottom chord.As a result, the bottom chord shortens and the top chordlengthens. This causes the truss to arch and lift thebottom chord with the ceiling separating it from the wall.Proper attic ventilation removes the damp air andreduces the chance of truss uplift.

5.4 Wall Sheathing

Note:1. Panels to be minimum 600 mm wide typically. Minimum width to be 1220 mm wide when used as bracing.

Figure 7 provides the recommended installation details forwall sheathing along with the maximum support spacing.Wall sheathing panels may be installed vertically orhorizontally. A 3 mm (1/8”) gap should be left betweenpanels and around openings for windows and doors. Therequired fastening for wall sheathing is shown in Table 5.Blocking or diagonal bracing is generally not required withOSB sheathing unless specified by the building designer.Blocking is required at the edges of OSB shearwalls,which are specially engineered to transfer lateral wind orearthquake forces to the foundation in engineeredconstruction (see Section 6.5). Sheathing panels shouldcover the upper plate and lower sill to ensure the load pathfrom roof to the foundation is maintained.

Part 9 of the NBCC requires that at least one layer ofsheathing membrane be applied beneath siding, stucco ormasonry veneer. Sheathing membrane may be omittedbeneath siding if the joints are formed to effectivelyprevent the passage of wind and rain. However, the SBArecommends the use of sheathing membrane under anytype of exterior cladding.

Where a stucco finish is desired the sheathing should becovered with a double layer of sheathing membrane toprevent moisture saturation of the panels during stuccocure or from wind driven rain. Note that Part 9 of theNBCC specifies a minimum panel thickness of 12.5 mmand does not allow the use of tar-saturated felts or papers

Framing

Leave a 3 mm (1/8”)minimum gap on edgesand around openings

Support all paneledges if panels areused for bracing oron shear walls

Stagger vertical joints inhorizontal applications

Figure 7 Wall Sheathing InstallationPanel sheathing applied with or across supports as shown, and notpermanently exposed to the weather.

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Wall Sheathing Requirements (Horizontal and Vertical Application)

CSA O437.0 OSB/ CSA O325.0 OSBMaximum Waferboard Minimum Panel

Type of Exterior Finish stud spacing Minimum Thickness Mark

O-2 O-1/R-1

• Siding attached to framing members, 400 mm - 16” 6.0 mm 1/4” 6.35 mm W16 or 2R16furring members or blocking 600 mm - 24” 7.5 mm 5/16” 7.9 mm W20 or 2R20

• Wood shingles and shakes or vertical 600 mm - 24” 7.5 mm 5/16” 7.9 mm W20 or 2R20metal siding attached to sheathing

• Asbestos cement shingles 600 mm - 24” 9.5 mm 3/8” 9.5 mm W24 or 2R24attached to sheathing

• Vertical lumber or stucco lath 600 mm - 24” 12.5 mm 1/2” 12.7 mm 1R24attached to sheathing

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to be used as sheathing membrane beneath stucco. The joints in the sheathing membrane should be lappeda minimum of 150 mm. Framing around all openingsshould be protected with two layers of sheathingmembrane. In addition, proper flashing design and goodconstruction techniques should insure that free watercannot enter the space between the membrane and thesheathing. Additional information about stuccoapplication over OSB is available from the SBA.

5.5 Exterior Siding

Figure 8 provides the recommended installation detailsfor OSB exterior siding. Prior to installation all paneledges should be treated with a primer or sealer. Duringinstallation a 3 mm gap should be left between paneledges to allow expansion without buckling. All panel

edges must be supported by framing members or notless than 38x38 mm blocking. Furring may also be usedas recommended by the NBCC for other types ofcladding.

The vertical joints between panels should be protectedagainst water entry with caulking or batten strips andflashing is required at horizontal joints unless the sidingis lapped. The siding should be fastened with casing orsiding nails spaced at 150 mm along panel edges, 300mm along intermediate supports and 10 mm minimumfrom panel edges. Other equivalent fastening schedulesmay be used.

Following installation OSB siding should be protected bya good exterior quality finishing system (see Section 4.2).

Notes:1. The minimum thickness of grooved or striated panels is measured from the panel back to the bottom of the groove.2. OSB to conform to CSA O437.0, Grade O–2.

Figure 8 Exterior Siding Installation

Minimum Thickness1,2

Stud Spacing Fastened Directly to Framing or Furring Fastened to Approved Sheathing Nail Size and Type

400 mm - 16” 9.5 mm (3/8”) 7.5 mm (5/16”) 51 mm (2”) corrosion-resistant casing or siding nails

600 mm - 24” 12.5 mm (1/2”) 7.5 mm (5/16”)

OSB siding

Seal allpanel edges

Support

OSB siding

25 mm (1”)minimum lapat foundation

CAULKED APPLICATION BATTEN APPLICATION

200 mm (8”)minimumabove grade

200 mm (8”)minimum above grade25 mm (1”)

minimum lapat foundation

3 mm (1/8”) minimum gap between panels; caulk all joints

Horizontaljoints lap 40 mm (1-1/2”)minimum orflash

Minimum 3 mm (1/8”) gap between panels and at door and windowopenings

Note: Sealing of panel edges is most conveniently performed while panels are neatly stacked.

Table 9. Maximum Allowable Loads for CSA O325 Rated OSB Roof Sheathing

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5.6 Moisture during Construction

OSB structural sheathing is manufactured with anexterior grade adhesive. Sloped OSB roofs will allowrain water to run off. If ponding occurs on floors or otherflat surfaces SBA recommends excess water bebroomed off or several 25 mm diameter holes be drilledin the ponding area to allow the water to drain.

5.7 Detailing and Good Construction Practice

OSB like other wood products should be protected fromexcess moisture. Ensure that sheathing paper or “housewrap” is properly installed under stucco or brick veneer.Provide adequate flashing over openings in brick veneerwalls so that the wall cavity will drain when moisturepenetrates the brick. In addition, provide adequateflashing at all roof and wall openings and at changes inhorizontal and vertical direction (for example insidecorners, valleys, dormers). Properly caulk the spacewhere siding butts against door and window frames.

All panels should be spaced 3 mm (1/8”) on all sides toallow for expansion due to moisture changes, and onlong floors or roofs install an expansion joint every 24 m.Extra fastening and closer spacing is required in highwind or seismic areas. Check with the local buildingauthority for these special requirements.

5.8 Shipping, Handling and Storage

OSB is a wood based product. Reasonable care is

required in warehousing and on the job site to protectpanels from mechanical damage and lengthy exposure to adverse moisture conditions. For best results handlepanels as little as possible. Ship in the original lift loadsif possible. Use care in handling the panels to avoiddamaging corners and edges on the job site and keeplifts out of the mud.

If storing OSB panels for long periods, store lifts indoorsor under cover with enough supports that panels remainflat. Provide air circulation around panels by keepingcovers open and away from sides and bottoms of liftloads.

5.9 Maximum Loads for OSB Panels

Table 9 provides the maximum allowable loads for ratedOSB roof sheathing panels. This table was developedfollowing extensive testing of these products in researchfacilities plus many years of successful applications inconstruction.

In addition, panels meeting CSA O325.0 have beenperformance tested for a 1.7 kPa loading with adeflection limit of L/240, where L is the spacing betweensupports.

OSB rated floor sheathing panels meeting CSA O325.0have been tested for a 4.8 kPa uniform load with adeflection limit of L/360.

Panel Mark Thickness Maximum Span, Maximum Span, Allowable Live loads, kPa4 ,3

(CSA 325) (mm) with Edge without Edge Spacing of Supports, centre to centre (mm)Support 2 Support

(mm) (mm) 300 400 500 600 800 1000 1200

2R20 7.5, 9.5 500 500 5.7 2.4 1.4

2R24 9.5, 11.0, 12.5 600 5004 8.1 4.8 2.8 1.4

1R24 11.0, 12.5 600 6005 9.1 4.8 3.1 1.9

2R32 12.0, 12.5 800 7005 10.4 7.4 5.7 3.3 1.4

2R40 15.0, 15.5 1000 800 10.0 7.8 6.0 2.8 1.4

2R48 18.0, 18.5 1200 900 10.0 7.8 5.5 2.8 1.7

2R606 22.0, 25.0 1500 1200 10.0 7.8 5.5 3.3

Notes:1. Values are valid when long panel dimension is across supports and for panels 600 mm or wider. For narrower panels, additional edge supports are required.2. Tongue–and–groove edges, panel edge clips (one centered between supports, except two equally spaced between supports at 1200 mm o.c.),

limber blocking, or other.3. Values include an allowance for 0.5 kPa dead load. If higher dead loads are used, the live load should be reduced accordingly.4. 600 mm for 12.5 mm panels.5. For enhanced performance, SBA recommends minimum 1R24 at 400 mm o.c. and 2R32 at 600 mm o.c.6. Check with suppliers for availability.

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Structural Insulated panels (SIPS), also known as foam-core sandwich panels, are becoming increasingly popularfor use as structural floors, walls and roofs (see Figure

9). These productsprovide an alternatesolution for ownersand buildersconcerned withenergy efficiency anddwindling naturalresources. Thesepanels are typicallymanufactured in sizesfrom 1220x2440 mm(4’x8’) to 2440x7320mm (8’x24’) andhave quality certifiedOSB faces with eitherprecast or foamed inplace rigid foamcores. They arem a n u f a c t u r e dthroughout the U.S.and Canada in

modern quality controlled plants to fit a variety of homedesigns and can easily be erected on preparedfoundations by trained installers. Individual manufacturerscertify capacities for the panels in accordance with anASTM Standard or an ICBO evaluation report. IndividualU.S. manufacturers have national and local code approvalunder the National Evaluation System and Canadianmanufacturers are looking toward Canadian ConstructionMaterials Centre (CCMC) for evaluation. For moreinformation and a list of panel manufacturers, contact theStructural Insulated Panel Association (www.sips.org).

6.2 Wood I-joists

Proprietary OSB is used extensively for the webs ofprefabricated wood I-joists. Wood I-joists can be usedfor longer spans than conventional lumber, and becausethey are manufactured at a low moisture content, greatlyreduce performance problems such as nail pops andsqueaky floors that sometimes occur with conventionallumber.

Individual I-joist manufacturers certify design values fortheir products under ASTM Standard D-5055 and CSAStandard CSA O86. They also provide a wide range ofdesign information for use by the specifier or builder.

Wood I-joists can be cut to desired lengths either on thejob site or by order from the manufacturer. Most joistsare supplied with knockout ports for the installation ofelectrical or heating systems. These knockout ports arelocated within the joists so as not to effect strengthperformance. SBA recommends the use of 25.0 mmthick OSB rim boards equal in depth to the I-joist as partof the floor system for added strength and load-carryingcapacity (refer to ICBO ES Report AC124 “AcceptanceCriteria For Wood-Based Rim Board Products”). SBAdiscourages the use of nailed in place ordinary OSB wallsheathing alone in load bearing rim joist applications.For more information contact the SBA or members of theWood I-joist Manufacturers Association.

6.2.1 Engineered Floor Systems

Designers and builders are utilizing the superior load-carrying capability of the wood I-joist along with thicker(22.5 or 25.0 mm) OSB subfloor panels to construct anengineered floor system that gives superior performancein terms of deflection and vibration. This system is verypopular for long spans or under ceramic or marble tilefinished floors. For more information contact the SBA orthe I-joist manufacturer.

6.3 Renovation

OSB can be used in a variety of applications inrenovation projects. In addition to sheathing, otherapplications include replacing or levelling original floors,closing exterior openings due to relocation of doors andwindows, or modifying roofs to allow for construction ofdormers or lofts. Solid OSB panels are often used torestrict entry to buildings being renovated or as a safetyfence around the renovation site. The versatile panelsalso make excellent hidden forms for the construction ofconcrete platforms or exterior concrete stairs.

6.4 Industrial Applications

OSB is commonly used in industrial applications. Thestrength, workability, versatility, value and lack offormaldehyde emissions, make them excellentalternatives to plywood and solid wood. Panelsspecifically identified or rated for roof, wall, and floorapplications in wood frame construction may be used directly, or SBA members can customize panelthickness, size or properties of OSB for specific

6.0 OTHER USES FOR OSB

6.1 Structural Insulated Panels

Interior sheathing

Exterior sheathing

FoamCore

Figure 9 Typicalstructural insulated panel

Notes:1. All panel edges backed with 38 mm or wider framing. Sheathing installed either vertically or horizontally. Space nails at 300 mm on centre along

intermediate framing members. Panels applied directly to framing.2. Shear resistance values are for short term duration of load, dry service conditions and common nails only. For other loading, blocking or nail type

conditions, refer to CSA O86-01.3. Values are for lumber with a moisture content of 15% or less prior to nailing. For unseasoned lumber, multiply the values by 0.8.4. OSB to meet CSA standards O325, O437 or O452. Check for availability before specifying.5. Values are for S-P-F framing lumber only. For other species of lumber, multiply the shear resistance values by the following factors:

D.Fir-L 1.25Hem-Fir 1.12Northern Species 0.87

23

applications. These advantages have been recognizedby industrial buyers particularly for crating andpackaging, materials handling and manufactured housingapplications. More and more OSB is chosen for crating, pallets, bins, furniture frames, display racks and storefixtures.

6.5 Engineering Design

Design values for OSB are given in the new CSA O86-01“Engineering Design in Wood” for panels meeting CSAO452 “Design Rated OSB” and CSA O325 “ConstructionSheathing”. Design values for shearwalls or diaphragmsare also provided for panels meeting CSA O325, CSA O452 or CSA O437 “Strandboard and Waferboard”.New in-grade tests have proven that CSA O325 panelscan meet the minimum strength and stiffnessrequirements of CSA O437. Contact the SBA office forfurther information on equivalent performance.Additional information on Engineering Design is available

in the separate SBA publication “Design Rated OSB -Design Manual”.

6.6 Horizontal Diaphragms and Shearwalls

OSB sheathing panels can be used to create horizontaldiaphragms and shearwalls in order to brace buildingsfor wind and seismic loads. Tables 10 and 11 containthe factored shear resistance for shearwalls anddiaphragms sheathed with OSB meeting CSA StandardsO325, O437 or O452. CSA O86 recognizes that OSB isequivalent to plywood in diaphragms and shearwalls.Note that proper design of shearwalls and diaphragmsinclude sizing the perimeter members for axial forces.Also, the connections between the diaphragm andshearwall must be engineered. The shearwall must alsobe adequately anchored to the supporting wall orfoundation and the corners fastened down to prevent thewall from overturning under lateral loads.

CSA O325 Nominal Common Nail NailPanel Panel Nail Penetration in SpacingMark Thickness Diameter Framing at Panel Edges

(mm) (mm) (mm) (mm)150 100 75 50

2R24 9.5 2.84 31 3.48 5.28 6.83 8.95

3.25 38 3.86 5.60 7.15 9.27

1R24/2F16 11.0 3.25 38 4.19 6.12 7.86 10.20

2R32/2F16 or 1F16 12.5 3.25 38 4.57 6.63 8.56 11.20

3.66 41 5.41 8.05 10.50 13.40

2R40/2F20 15.5 3.66 41 5.92 8.95 11.70 15.30

Table 10. Factored Shear Resistance (kN/m) for OSB Shearwalls with S-P-F Framing

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Notes:1. Space nails at 300 mm on centre along intermediate framing members. Nails placed not less than 9 mm from panel edge. Panels applied directly to

framing.2. Shear resistance values are for short term duration of load, dry service conditions and common nails only. For other loading or nail type conditions,

refer to CSA O86-01.3. Values are for lumber with a moisture content of 15% or less prior to nailing. For unseasoned lumber, multiply the values by 0.8.4. OSB to meet CSA standards O325, O437 or O452. Check for availability before specifying.5. Values are for S-P-F framing lumber only. For other species of lumber, multiply the shear resistance values by the following factors:

D.Fir-L 1.25Hem-Fir 1.12Northern Species 0.87

6. (*) Two lines of fasteners required

Note: Framing is permitted in either direction for blocked diaphragms

The use of OSB panels over metal framing members ispossible with modern fastening methods such as self-drilling, self-tapping screws or screw-shank nails. Thesecan be used to attach a wide range of panel thicknessesto steel flanges, or lighter members such as cold-formedsteel sections. Construction adhesives recommended bythe metal framing manufacturers should be used withhardened screw-shank nails.

Since threads extend only part way up the shank ofscrews or nails, it is important to specify a fastenerlength sufficient to engage the metal framing. Load-spanrecommendations are the same as for wood-framesystems described elsewhere in this manual. (ContactSBA for additional information.)

6.7 OSB Panels over Metal Framing

Common Min. CSA O325 Nominal Min. Blocked Diaphragms Unblocked DiaphragmsNail Nail Panel Panel Nominal Nail Spacing (mm) at Boundaries (All Cases) and at Nail Spacing at 150 mm

Diameter Penetration Mark Thickness Width of Continuous Panel Edges Parallel to Load Maximum at Supported Edges(mm) in Member (mm) Framing (Cases 3 - 4)

(mm) (mm) 150 100 64 50 Load Perp. toUnblocked

Nail Spacing at Other Panel Edges, mm Edges All Other 150 150 100 75 Case 1 Cases 2-3-4

2.84 31 2R24 9.5 38 3.22 4.38 6.57 7.08 2.90 2.19

64 3.67 4.89 7.34 8.37 3.22 2.45

3.25 38 2R24 9.5 38 4.19 5.60 8.44 9.66 3.80 2.83

64 4.70 6.31 9.47 10.90 4.19 3.15

1R24/2F16 11.0 38 4.44 5.92 8.82 10.30 4.06 2.96

64 5.02 6.63 9.98 11.60 4.44 3.35

2R32/2F16 12.5 38 4.70 6.31 9.27 10.30 4.19 3.15

64 5.28 7.02 10.50 11.60 4.64 3.48

3.66 41 2R32/2F16 12.5 38 5.09 6.76 10.00 11.60 4.44 3.35

64 5.67 7.53 11.40 12.90 5.09 3.80

2R40/2F20 15.5 38 5.60 7.47 11.20 12.90 5.02 3.80

(or 1F20) 64 6.31 8.37 12.60 14.20 5.60 4.19

2R48/2F24 18.5 64 11.30(*) 16.40(*)

(or 1F24) 89 13.10(*) 18.80(*)

Table 11. Factored Shear Resistance (kN/m) for OSB Diaphragms with S-P-F Framing

D e f l e c t i o n :The amount a panel deflects between two supports when carrying a load. Maximum deflection for roof loads is usually L/240 for live load only or L/180 for total load. For floor loads, maximum deflection is usually L/360 for live load plus dead load.

Exterior bond panel: A panel bonded with a thermosetting binder and with the quality of the adhesive bond controlled in production by means of a specified bond durability test.

Major axis (Strength axis): The axis with the greater stiffness and strength in bending. For OSB, the direction of alignment of the strands in the face layers of the panel.

Minor axis:The axis with the lesser stiffness and strength in bending. For OSB, the direction at right angles to alignment of the strands in the face layers of the panel.

Nominal thickness: The grademark specified thickness marked on the panel.

OSB: An abbreviation for Oriented Strand Board; a type of mat–formed panel with oriented or aligned strands resulting in directional properties. OSB conforms to standards such as CSA O325, O437, O452, US DOC PS 2 or other national standards (JAS, EN).

Performance Rated (or Rated): Panels which have been tested to meet specific loading and deflection conditions from impact, concentrated static, uniformly distributed and racking loads for panels intended to span two or more supports.

S t r a n d :A specialized knife-cut wood flake of controlled thickness and a length along the grain orientation of at least twice and usually many times its width.

Touch–Sanded: A process that removes material from the panel surface to provide a uniform thickness. Tongue and Groove panels are usually touch–sanded.

Thermosetting binder: An adhesive or binder which when fully cured is not softened by heat, and will not break down in the presence of m o i s t u r e .

Wafer: A specialized knife cut wood flake having a controlled length of at least 30mm (1 1/4”) along the grain, a controlled thickness and a variable width.

A PA - The Engineered Wood Association: An industry association of plywood, OSB, glulam and engineered wood manufacturers. They supplied some information found in this manual. APA provides a quality assurance program for its member companies.

HUD: The U.S. Department of Housing and Urban Development. HUD sets standards for government financed construction and manufactured homes.

P S I :Professional Service Industries Inc, Pittsburgh Testing Laboratory; a compliance, assurance and inspection agency with wood products testing facilities in Eugene, OR.

T E C O :A U.S. national inspection and testing agency with wood products testing facilities in Madison, WI, Eugene, OR, and Shreveport, LA.

APPENDIX A - GLOSSARY OF TERMS

25

26

APPENDIX B - SBA MEMBER PLANT LOCATIONS

1

8

6

2

Poland

France

3

4

7

Brazil

U.S.A.

5

Canada

27

SBA MEMBER COMPANIES

Member Companies Address Telephone and Fax Mill Locations Map #Numbers (Sales Office) Reference

Grant Forest Products Inc. 2233 Argentia Road 905-858-3200 Englehart, ON Canada 1Mississauga, ON Canada L5N 2X7 905-858-3208 Timmins, ON Canada 2

ISOROY S.A. 54-56 rue d’Arcueil, SILIC 135 33-1-56-30-20-00 Châtellerault, France 3Immeuble Amsterdam 33-1-57-02-12-7194523 Rungis Cédex, France

Kronopol Sp. z o.o. ul. Serbska 56 48-68-363-1100 Zary, Poland 468-200 Zary, Poland 48-68-363-1262

Langboard Inc. P.O. Box 837, Hwy 84 East 229-263-8943 Quitman, GA U.S.A. 5Quitman, GA U.S.A. 31643 229-263-5535

Martco Partnership P.O. Box 1110 318-445-1973 Morrow, LA U.S.A. 6Alexandria, LA U.S.A. 71309 318-443-0159

MASISA do Brasil Ltda. Rua Visconde do Rio Branco 55-41-324-0334 Ponta Grossa, Brazil 71341-8 Andar 80.420-210, 55-41-219-1870Curitiba PR, Brazil

Panneaux Tembec OSB 775, 122 Street 888-343-0735 St-Georges de Champlain, 8Tembec Forest Products Group St-Georges de Champlain, QC 819-538-0595 QC, Canada

Canada G9T 5K7

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BASF Corporation

Borden Canada

Canadian Willamette Industries Inc.

Eugene Forest Systems Ltd.

Huntsman Polyurethanes

NGM International Inc.

Tembec Resins Division

TSI

UMA Engineering Ltd.

Valspar Corporation

Specialty Wood Journal Thermapan Industries

Ecole Supérieure du Bois - Nantes

Louisiana State University

Michigan Technological Institute

Mississippi State University

Pennsylvania State University (PHRC)

University of British Columbia

University of Hamburg

Université Laval

University of Minnesota (NRRI)

University of New Brunswick (WSTC)

University of Tennessee

University of Toronto

Virginia Polytechnic Institute

West Virginia University

Alberta Research Council

American Wood Council

Canadian Wood Council

COMACO, Mexico

European Panel Federation

Forintek Canada Corporation

North American Coalition on Green Building

Sustainable Forestry Certification Coalition, Canada

Wilhelm - Klauditz Institute, Germany

Wood Panel Bureau, Canada

Wood Promotion Network, North America

Wood WORKS!, Canada

ASSOCIATE MEMBERS

ALLIED MEMBERS

RESEARCH MEMBERS

AFFILIATED WITH