CHAPTER B3

WOOD BASED PANEL PRODUCTS Wood is the most popular building material in the world, but prior to the advent of wood based panel products, it had some disadvantages that made it less than ideal for many projects. Wood is an organic material, so its strength is not uniform from one piece to the next. Also wood is composed of long fibres arranged in layers. So its strength varies according to the direction of applied load. For example, solid lumber is stronger along the grain than across the grain. The harvesting of smaller diameter trees as well as characteristics of the wood that prevent the recovery of high grade structural lumber has resulted in only about 30% of the tree being converted to lumber. Therefore, before the introduction of wood based panel products, some wood projects were becoming more difficult and expensive than they are today. As building sizes and market demand for wood grew, the need to use wood more efficiently became more important. Plywood was first manufactured in 1905 and rapidly became a solution to some of the above limitations. Made

from a series of veneers glued in layers at right angles to each other, its benefits were obvious because plywood made efficient use of a log, it could be made in panels larger than the trees it came from and it was almost equally strong in all directions. Demand grew quickly. Plywood was first used for doors, cabinets and trunks and later found a major market as automobile running boards. By the 1940s, with the introduction of waterproof glue, plywood began to be used in building construction. Today there are dozens of wood panel products used in all facets of construction and manufacturing. Some, like plywood, retain the look, feel and characteristics of the lumber they were made from. Others are barely recognizable as wood. What they all have in common is that they represent major progress in the effective and efficient use of one of man’s oldest and most popular building materials.

COMMON WOOD BASED PANEL PRODUCTS VENEER PANEL PRODUCTS

Sanded Plywood - Softwood plywood manufactured with one or both sides filled and sanded for use in projects where appearance is important. Sheathing - Unsanded plywood manufactured and graded for strength and stiffness, engineered for use as roof, wall or floor sheathing, or for combination sheathing/underlayment. Siding - Engineered for structural performance but manufactured with decorative faces for use as finish siding. Hardwood Plywood - Manufactured and graded for interior finish uses such as cabinets, doors and furniture. Common species include birch, oak, maple, ash, cherry, mahogany, walnut and lauan.

B3 WOOD BASED PANEL PRODUCTS

Note: Always consult your provincial and local codes

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COMMON WOOD BASED PANEL PRODUCTS (continued) Composite Panels - Softwood or hardwood panels with non-veneer cores and veneer faces and backs, used primarily for siding (softwood) or cabinet making (hardwood). Medium/High Density Overlay - (MDO and HDO) - Veneer panel with a resinimpregnated face that is smooth, hard and weather-resistant. MDOs are primarily used when painting exterior signs, tuck roll-up doors, etc. HDOs are primarily oiled and used as multi-use concrete forming. Treated Plywood - Plywood may be treated with decay resistant chemicals for use in treated wood foundations or with fire-retardant for use in some commercial projects. Concrete form - Concrete form plywood, filled and sanded on the face and oiled to make it reusable. Also manufactured with medium or high density overlays.

RECONSTITUTED PANEL PRODUCTS

Particleboard - Wood particles (approx. sawdust size) bonded with resins and formed into panels under heat and pressure. Smooth, dimensionally stable panels are used primarily for floor underlayment or in manufacturing cabinets and doors. Waferboard - Wood wafers (approx. 3" square) formed into sheets and bonded with wax and resins under heat and pressure. Wafer size and random orientation result in enough strength for use as roof, wall or floor sheathing. 3

1

Oriented Strand Board (OSB) - Wood strands (approx /8"x2 /2") laid in three or more directionally oriented layers at right angles to each other, like plywood veneers. Bonded with wax and resins and formed into panels under heat and pressure. Used for roof, wall and floor sheathing.

FIBREBOARD PANELS

All fibreboards are manufactured by chemically breaking wood particles into essential fibres, then interfelting them into panels. The primary difference among fibreboard products is the density of the panel and the additives that make different panels specially suited for different applications. 1

Insulation Board - Typically /2" and thicker. Includes sound deadening board, prepainted (“white face”) building board, asphalt impregnated sheathing, structural building board, ceiling tile and backer board. 3

7

Medium Density Hardboard - Typically /8" and /16" thick, manufactured and sold either preprimed or prefinished as panel and lap siding, or for roofing shingles. Also used for doors, soffits and other applications where it can be protected from moisture and weather. 1

1

High Density Hardboard - Typically /8" and /4" thick, manufactured for use as underlayment, for curved forms and in industrial applications. Sold as “standard hardboard”, but may also be tempered for extra hardness and moisture resistance. 1

Medium Density Fibreboard (MDF) - Typically /4" and thicker. Similar to particleboard in appearance, used in cabinet manufacturing.

PRODUCT OVERVIEW PLYWOOD Wood veneers have been around for centuries. The ancient Egyptians used veneer to build furniture and make paper. Nineteenth century woodworkers handcrafted plywood panels from hardwood veneers. But it wasn’t until the beginning of the twentieth century that the first wood panel products for general construction use were invented. The first softwood plywood panels were also handmade, but today, nearly the entire manufacturing process is automated. When logs arrive at a plywood mill, they are first scaled to find approximate yield, graded and sorted. The bark is removed and each log is cut to peeler blocks about 8'-4" long. Peeler blocks are turned on a lathe slicing away 1 a continuous sheet of veneer /10" to 1/4" thick. The veneer is then clipped to size, dried to about 5% moisture content, graded and sorted. PEELING VENEER FROM A LOG

When the manufacturing process is done, the panels are banded into units, wrapped and shipped to wholesalers and distributors. Softwood plywood is used mainly in general construction. It is manufactured in thicknesses 3 1 ranging from 9.5 mm to 28.5 mm ( /8" to 1 /8"). The most common size is 4'x8', but other sizes are made for special uses. Hardwood plywood has hundreds of specialty uses, almost all in finish applications. It may be available in either imperial or metric sizes, 1 3 usually ranging from /4" to /4" thick, 4'x7', 4'x8' and 4'x10' are the most common sizes. We’ll cover plywood types, grades and uses more thoroughly later in the chapter. RECONSTITUTED WOOD PANELS Particleboard, waferboard and OSB look like first cousins to someone who doesn’t know better, but they really have a lot less in common than meets the eye. The manufacturing process is superficially the same for all three: wood is mechanically reduced to small pieces (particles, wafers or strands) that are carefully sorted for size and shape. Once dried to a specified moisture content (usually around 3%), the pieces are coated or blended with wax and resins, then formed into panels under heat and pressure. Panels are then trimmed to size, stacked, banded, wrapped and shipped.

Defects are cut out and patched, then the sheets of veneer, called plies, are sprayed with glue and sandwiched into layers with each succeeding layer at right angles to adjacent layers (except 4-ply). Veneer “sandwiches” are then sent through the hot press and bonded under heat and pressure.

The difference is in the physical properties of the three products.

Once bonded, plywood panels are trimmed to size and then either graded and stamped or sent on for further remanufacturing such as sanding, resawing, grooving, etc.

Particleboard is manufactured for industrial and general use. Both standard and premium grades are available; the primary difference is density. Premium particleboard is most often used in

Particleboard Particleboard’s primary selling points are its smooth surface, solid core and resistance to warp. It makes a good base for countertop laminates because of its smoothness and stability. It makes better underlayment than plywood, because there are no voids in the core that might dent under resilient flooring. But particleboard has little structural strength and a tendency to swell and disintegrate when it gets wet.

making cabinets and countertops, while standard is more common for underlayment and general construction uses.

WAFER ALIGNMENT IN OSB AND WAFERBOARD (
identifies wafer alignment)

1

Thicknesses range from 1/4" to 1 /8". Common sizes are 4' wide and 8' to 12' long. Premium particleboard is usually sold in 49"x97" sheets, to reduce cutting waste. Waferboard And Oriented Strand Board The driving force behind developing waferboard was to make a panel that could compete with plywood in structural uses, using forest products that would otherwise be wasted. Waferboard is made from trees too small for lumber or veneer production. Logs are cut to 8' lengths, debarked and “slashed” into wafers about 3"x3". This size offers the best bonding surface and the square shape and random orientation make waferboard equally strong in both directions. Although waferboard is strong enough for many structural uses, it can’t compete head-to-head with plywood. Research revealed that it was 3 better to cut the wood into smaller strands, /16" 5 1 to /8" wide and 2 /2" long and then form the panel in succeeding layers at right angles to each other. The resulting product—oriented strand board—was nearly twice as strong and stiff as waferboard and (depending on the product) approaching or about equal to plywood. The figure “Wafer Alignment in OSB and Waferboard” shows the ways in which wafers are aligned in the various products. It was many years after plywood was introduced before it was accepted by builders as an alternative to board sheathing. Similarly, waferboard and OSB were slow to catch on in some locations. When you sell them, your customer may have some objections based on some wrong ideas about non-veneer panels and you’ll have to deal with those objections. An argument against non-veneer structural panels is that the edges tended to swell and, in fact, early panels did.

But both waferboard and OSB have changed much since they were first made. New resins have made them more resistant to edge swelling. They still expand and contract more than plywood, but your customer can allow for 1 that by spacing the panels /8" apart when using them for roof, wall or floor sheathing. Waferboard, OSB and particleboard are also 20% to 25% heavier than plywood, which makes them more expensive to ship and more difficult to use. The trade-off is that they are less expensive and they make efficient use of the trees that otherwise might not be used for valueadded structural wood based products. Fibreboard Panels Fibreboard panels sometimes look like nonveneer structural panels, but differ in some important ways. Particle panels such as particleboard, waferboard and OSB are made by mechanically breaking wood into smaller pieces, then regluing the pieces.

Fibreboards are made by dissolving wood into its basic components, then rebonding the wood fibres in a process called interfelting.

Besides providing a finished ceiling, a primary advantage of ceiling tile is its sound deadening qualities.

Other agents are often added during the interfelting process to add strength, increase resistance to moisture or decay, or otherwise improve the product.

Structural insulating board has some value in reducing sound transmission, but most of the reduction is due to patterns in the tile that break up or absorb sound waves. These tiles are called acoustic tiles or acoustic panels.

There are two fundamental types of fibreboards: insulation boards and hardboards. The main differences are density and the special additives that make them suitable for specialized projects.

Ceiling tile also may be manufactured from a fire-retardant mineral fibre and from fibreglass insulation with a vinyl facing.

Insulation Board

Hardboards

Insulation board is the lowest density fibreboard. Products commonly stocked at home centres and lumberyards include sound deadening board, “white face” building board (often used for bulletin boards) and asphalt impregnated sheathing (AIS). The most common size of these products is 1/2" - 4'x8', though AIS is often 25 4'x9' in /32" thickness.

Two types of hardboard are sold in most home centres and lumberyards: medium density and high density. Medium density hardboard is 7 commonly sold in /16" thickness, made into panel and lap sidings and roofing shingles.

AIS was once a popular exterior sheathing material. Its use has declined as foam insulation has become more popular.

Panel sidings are generally sold in 4'x8', 4'x9' or 4'x10' sheets. Lap sidings are usually 16' long and normally either 8" or 12" wide. Either style can be embossed to look like wood grain, stucco, or other materials. Hardboard siding is usually sold preprimed or prefinished.

Structural insulating board is denser than other insulation boards. It is stronger, more solid and more weather resistant than other insulation boards and has twice the insulating value of wood. It is used as exterior sheathing and siding (check your local building codes), soffit material, interior wall and ceiling panels, carpet underlayment, truck bed lining and bulletin board material.

TYPICAL HARDBOARD LAP SIDING PATTERNS

Structural building board is generally sold in 1/2" 5 or /8" thick, 4'x8' sheets. It is also made in 4'x10' and 4'x12' sizes. It is also combined with other panels—a foam insulation panel, for example—for special uses such as roof decking. Ceiling tile is also made from structural insulating board. There are two basic types of ceiling tile: tiles and lay-in panels.

What most home centre employees simply call “hardboard” is technically high density hardboard.

Tiles come in 12"x12" sizes and may be stapled to furring strips through the interlocking flanges, glued with mastic to an existing ceiling, or clipped in place in a premanufactured grid.

Sold in /8" and 1/4" thicknesses, it comes in three grades: s t a n d a r d , t e m p e r e d and underlayment.

Lay-in panels are made in 24"x24" and 24"x48" sizes. They are designed to fit in a metal grid suspended from the ceiling joists.

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Standard hardboard is used for a variety of projects, including sliding cabinet doors, backing for shelving units and drawer bottoms.

Manufacturers use it for flat panels in interior stile-and-rail doors and for flush door skins. Used for door skins, it may be embossed to look like wood grain, or even moulded to look like a raised panel stile-and-rail door. Unless the manufacturer specifies otherwise, assume that any door with a hardboard skin is intended only for interior use.

HIGH DENSITY HARDBOARD USED AS UNDERLAYMENT

Generally, but not always, standard hardboard is smooth on one side with a screen back on the other. Standard hardboard isn’t very waterresistant. It can be cut, drilled and nailed fairly easily. Tempered hardboard is denser and more waterresistant. It is usually smooth on both sides and is usually (but not always) a darker colour than standard hardboard. The only reliable way to distinguish standard hardboard from tempered is that most manufacturers paint a bright green stripe on the edges of standard hardboard and a bright red stripe on the edges of tempered hardboard. Both standard and tempered hardboard are sold in 4'x8' sheets, although many home centres also sell pre-cut 2'x4' and 4'x4' pieces. Either also may be available as perforated 1 pegboard in 1/4" and /8" thicknesses. Pegboard is used with various hooks to hang all kinds of things. Underlayment grade hardboard is less dense than standard hardboard, so it’s weaker and less resistant to moisture. It absorbs glue and is easier to nail than standard or tempered hardboard. It is sold as 1/4", but is sanded to less than full thickness, often called "0.215." Underlayment grade hardboard comes in 4'x4' sheets. Medium Density Fibreboard

MDF is smoother than particleboard and holds screws better—especially in the edges. It can be used for nearly anything particleboard is used for: cabinet boxes, raised panels in interior stileand-rail doors, as a substrate for countertop laminates and as a paintable finish material. As you might expect, MDF is also more expensive than particleboard. It is available from 1 1 /4" to 1 /2" thick, depending on the manufacturer and is sold in either 4'x8' or 49"x97" sheets.

STRUCTURAL PANEL PRODUCTS The remainder of this chapter deals with structural panel products of softwood plywood, OSB and waferboard and their uses and with non-structural products of hardwood plywood. In reviewing the structural panel products, let’s first deal with grade marking and then follow with descriptions of products manufactured and the end use of these products in floor, wall, roof and other applications. The figures and tabular information for softwood plywood, waferboard and OSB is based on information generally available from: Canadian Wood Council (CWC), Canadian Plywood Association (CanPly), Structural Board Association (SBA) and Canadian Institute of Treated Wood (CITW).

Medium density fibreboard, or MDF, is more common in industrial and manufacturing applications than in retail stores. But if you don’t carry it in sheet stock, you may be selling MDF whenever you sell cabinets, doors or millwork.

SOFTWOOD PLYWOOD GRADE MARKS

MDF looks a lot like fine particleboard, but several characteristics make it a better product. Since it is a fibreboard, its edges are tighter than particleboard—less likely to flake and chip away.

Like lumber, wood panel products are graded according to their intended use. Basically that means it doesn’t matter what the product is made of, only that its appearance or structural properties are adequate for its use.

International standard CSA O325.0-92 “Construction Sheathing.” This standard does not identify panel grade criteria but identifies performance requirements that need to be met in construction. The long tradition of Canadian use of plywood manufactured to the CSA O121, CSA O151 and CSA O153 standards has generally resulted in Canadian manufacturers not using the CSA O325.0 standard as a basis for the acceptance of softwood plywood products.

Product standards—the basis of the grading system—are voluntary. No one forces a panel manufacturer to conform to them. But communities that have building codes require that products conform to product standards and meet their code requirements. Softwood panel grades are established according to standards published by CSA International. These standards are: • CSA O121-M1978 “Douglas Fir Plywood.” • CSA O151-M1978 “Canadian Softwood Plywood.” • CSA O153-M1980 “Poplar Plywood.”

The Canadian Plywood Association (CanPly)—a Standards Council of Canada (SCC) approved quality control agency—oversees much of the plywood quality control in Canada and ensures that the certified plywood meets the requirements of the above specifications.

(Note: Technically poplar is a hardwood species. However, it’s material properties are similar to that of several of the softwood species. Hence, for construction uses poplar plywood is typically manufactured to the CSA O153 standard.)

CANPLY LOGO

In addition, the National Building Code of Canada (NBCC) also references the CSA

HOW TO READ A CANPLY PANEL GRADE STAMP FACE STAMP ON CANPLY EXTERIOR PLYWOOD (Unsanded Grades) Indicates that the plywood has been manufactured by a member of the Canadian Plywood Association Indicates that this product is manufactured under CanPly Quality Certification Licensed mill number of the Canadian Plywood Association member: BC 000, AB 000, or SK 000

Indicates a completely waterproof glue bond Indicates species designation: DFP (Douglas Fir plywood), CSP (Canadian Softwood plywood) or Poplar plywood Indicates the CSA standard governing manufacture

EDGE STAMP ON CANPLY EXTERIOR PLYWOOD (Sanded and Unsanded Grades) Indicates that the plywood has been manufactured by a CanPly member and is quality certified Indicates a completely waterproof glue bond Panel grade Indicates species designation: DFP (Douglas Fir plywood), CSP (Canadian Softwood plywood) or Poplar plywood Licensed mill number of the Canadian Plywood Association member

PLYWOOD GRADES AND PRODUCTS Plywood Grades Grade* Good Two Sides (G2S) Sanded

Specify By** DFP Poplar

Good One Side (G1S)

DFP

Select - Tight Face (SEL TF) Select (SELECT)

DFP or CSP DFP CSP Poplar DFP CSP Poplar

Sheathing (SHG)

Veneer Grades*** Face Inner Back Plies A

C

A

A

C

C

B+

C

C

B

C

C

C

C

C

Characteristics Sanded. Best appearance both faces. May contain neat wood patches, inlays or synthetic patching material. Sanded. Best appearance one side only. May contain neat wood patches, inlays or synthetic patching material. Unsanded surface openings shall be filled. May be Cleaned and Sized (C&S). Unsanded. Uniform surface with minor open splits. May be Cleaned and Sized. Unsanded. Face may contain limited size knots, knotholes and other minor defects.

Typical Applications Furniture, cabinet doors, partitions, shelving, concrete forms and opaque paint finishes. Where appearance or smooth sanded surface of one face is important: cabinets, shelving, concrete forms. Underlayment and combined subfloor and underlayment. Hoarding. Construction use where sanded material Is not required. Roof, wall and floor sheathing. Hoarding. Packaging. Construction use where sanded material is not required.

CanPly Plywood Products Grade* EASY ROOF

EASY FLOOR

COFI FORM PLUS and COFI FORM

High Density Overlaid Medium Density Overlaid MDO 1 side MOD 2 sides

* ** *** +

Specify By** DFP CSP DFP CSP Poplar DFP (limits on thickness and species of face and inner plies)

DFP CSP Poplar DFP CSP Poplar

Veneer Grades*** B or C B or C

C C

C C

B or C B or C C

C C C

C C C

C

C

C

C

C

C

C

C

C

C

C

C

B+

C

B+

C+ C+

C C

C C+

Characteristics

Typical Applications

Milled with patented edge profile for easy Installation and edge support without H-clips. Milled with a patented edge profile for fast, easy Installation.

Roof sheathing and decking for residential, commercial and industrial construction. Floor and heavy roof sheathing for residential, commercial and industrial construction. Concrete forms and other uses where wet service conditions or superior strength requirements are encountered.

Special construction Douglas Fir panels with greater stiffness and strength providing improved properties particularly in wet service conditions. Available in regular sanded and unsanded grades and speciality grades with resin-fibre overlays. Also available with factory-applied release agent. Smooth, resin-fibre overlaid surface. Further finishing not required. Smooth, resin-fibre overlaid surface. Best paint base.

Bins, tanks, boats, furniture, signs, displays, forms for architectural concrete. Siding, soffits, panelling, built-in fitments, signs, any use requiring a superior paint surface.

All grades and products including overlays bonded with waterproof resin glue. For complete grade descriptions see CSA O121-M1978 DFP, CSA O151-M1978 CSP and CSA O153-M1980 Poplar For complete veneer grade descriptions see CSA O121-M1978 DFP, CSA O151-M1978 CSP and CSA O153-M1980 Poplar Permissible opens filled

The figure “How to Read a CanPly Panel Grade Stamp” on the page immediately before the “Plywood Grades and Products” table identifies the information provided on a certified plywood panel. In addition to CanPly certification, the Canadian Construction Materials Centre (CCMC) of the National Research Council of Canada evaluates plywood panel products and publishes acceptable products in their “Registry of Product Evaluations.” SOFTWOOD PLYWOOD GRADES AND PRODUCTS The CSA standards provide for three grades of veneer, A, B and C of which the highest grade is A. B grade can be “improved”, by filling permissible openings, when laid up in the plywood form. From these veneer grades plywood is manufactured in a number of grades as shown in the table “Plywood Grades and Products” on the previous page. For regular grades of plywood the grade names are based on the quality of the veneers used for the face and back of the panel. Several companies manufacture, beyond the regular sanded and unsanded grades, a number of speciality panels such as patterned, textured, grooved and tongue and groove (T&G) panels for floors and roofs. These panels are available under a variety of proprietary names. However, as CanPly’s members manufacture more than 90% of the plywood manufactured in Canada, the “Plywood Grades and Products” table also lists the products as referenced by CanPly. Two additional plywood panel grades are commonly available and are of particular interest to DIYers. Factory (DFP) or Shop (CSP and Poplar) are not accepted as regular grades because of minor defects. However, they are ideally suited for manufacturing uses or woodwork projects. Degrade panels are those which fail to meet the specific requirements for a regular grade. They are usually rejected because of production faults or oversize defects and cannot be used in structural applications covered by building codes. However, they can provide substantial areas of sound plywood and can be an economical choice for woodwork projects which do not require the entire panel area and where structural performance is not required.

Although the common size of plywood is 4'x8' (1220 mm x 2440 mm) plywood panels are available in lengths up to 2500 mm (981/2") and 5 widths from 600 mm (23 /8") to 1250 mm (491/4"). Panel thicknesses for sanded and unsanded grades are shown in the table below. PLYWOOD PANEL THICKNESSES Select and Sheathing Grades 6 mm 19 mm 7.5 mm 20.5 mm 8 mm 21 mm 9.5 mm 22.5 mm 11 mm 24 mm 12.5 mm 25.5 mm 14 mm 27 mm 15.5 mm 28.5 mm 17 mm 30 mm 18.5 mm 31.5 mm All thicknesses are metric. Some, but not all, thicknesses 3 approximate imperial dimensions, namely: 9.5 mm ( /8"), 1 5 3 12.5 mm ( /2"), 15.5 mm ( /8") and 19 mm ( /4"). Sanded Grades

OSB AND WAFERBOARD OSB and Waferboard panel grades are established according to the CSA International standard: • CSA O437.0 OSB and Waferboard As discussed in the previous section, the National Building Code of Canada (NBCC) also references the CSA International standard CSA O325.0-92 “Construction Sheathing.” This standard, which identifies performance requirements that need to be met in NBCC construction, is frequently used as the basis of Canadian acceptance of OSB and is almost exclusively used as the basis of acceptance of OSB in the United States. This is relevant to your understanding of the OSB and waferboard panel certification marking requirements as frequently there is “dual” referencing with the US equivalent Standard PS 2-92 “Performance Standard for Wood Based Structural Use Panels.” The Structural Board Association (SBA) is the Canadian based agency dealing with OSB and waferboard marketing and promotion. (SBA’s membership includes manufacturers located SBA LOGO not only in Canada but in Europe, South America and the US.) SBA works with a number of quality control certification agencies to certify

that their members’ products meet the requirements of the standards. The “representative” examples of these panel certification marks are shown below. The CSA O437.0 standard requires that all OSB and waferboard panels made in conformance with the standard are clearly marked with: 1. The manufacturer’s name or mill number. 2. The designation CSA O437.0. 3. The words “Exterior Bond” or “EXT. BOND”. 4. The appropriate mark R-1, O-1, O-2. 5. The nominal thickness in mm. 6. The direction of orientation if O-1 or O-2 grade. 7. THIS SIDE DOWN on the back of T&G panels. 8. If panels are for export, marked with “MADE IN CANADA” CSA O437.0 MARKING REQUIREMENTS MANUFACTURER’S NAME OR LOGO EXTERIOR BOND MILL 000 CSA O437.0 EXTERIOR BOND R-1 or O-1 or R O-2 12.5 mm MADE IN CANADA

The CSA O325.0 standard requires that all OSB and waferboard panels made in conformance with this standard are clearly marked, in addition to the CSA O437.0 requirements, with:

1. The designation CSA O325.0 2. The panel mark denoting the span rating and end use. 3. The nominal thickness. 4. The certification agency logo. CSA O325.0 MARKING REQUIREMENTS CONSTRUCTION SHEATHING EXTERIOR BOND MILL 000 CSA O325.0 1R24/2F16 12.5 mm CERTIFICATION AGENCY

OSB AND WAFERBOARD GRADES AND PRODUCTS The CSA O437.0 “OSB and Waferboard” standard contains three grades. Grade R-1 is waferboard, which is being phased out. Grades O-1 and O-2 are OSB panels. Building codes specifies the use of these panels by grade and by panel thickness. The O-2 grade thicknesses are a soft conversion of standard imperial sizes. The O-1 and R-1 thicknesses are a hard conversion (see the following page). Other panel thicknesses including 22.0 mm, 28.5 mm and 32.0 mm are available on special order. Panels 15.0 mm and thicker are manufactured either square-edged or tongue and grooved on the long edge. Most mills produce panels with textured surface

REPRESENTATIVE OSB AND WAFERBOARD CERTIFICATION MARKS

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

18.5

Grade O-1, R-1 (mm)

6.35

7.9

9.5

11.1

------

12.7

------

15.9

------

19.0

Imperial (in.)

1

5

3

7

15

1

19

5

23

3

/4

/16

/8

treatments for improved traction on sloping roofs. Regular panels are either unsanded or touch sanded, however the product may be ordered smooth sanded on one or both sides for industrial or decorative uses. As discussed earlier CSA Standard O325.0 “Construction Sheathing” is a performance based standard for floor, roof and wall sheathing. Panels installed on framing are evaluated for ability to carry loads and resist deflection under loading and conditions simulating or exceeding those experienced in service and during construction. This standard permits the use of panels to be of any thickness and made with either veneer or strands. The components must be bonded with phenol formaldehyde resin or an equivalent binder. The criteria for acceptance is the ability of the panels to perform, not how they are made. CSA O325.0 specifies rigorous performance tests for concentrated and uniform static loads under wet and dry conditions. Impact tests are specified as well as fastener holding capability. Physical properties of linear expansion, thickness swelling, panel stability and bond durability are also tested. The ability of a product to meet the performance requirements of a given end use is shown on the panel by a PANEL MARK. This panel mark consists of an end use mark followed by a span mark, e.g. 1F16. The end use markings are as follows: Mark 1F 2F 1R 2R W

End use Subfloor Subfloor used with panel-type underlay Roof sheathing without edge support Roof sheathing with edge support Wall sheathing

The span mark indicates the maximum o/c spacing of the supporting members in inches. The standard marks are 16, 20, 24, 32, 40 and

/16

/32

/2

/32

/8

/32

/4

48. Panels may qualify for more than one end use. For example, a panel may be marked 1R24/2F16/W24. Building codes specify the use of these panels by the panel marks (not thicknesses) to show the minimum panel permitted for specific end uses and spans. Construction sheathing panels are also marketed according to the panel marks. Actual thicknesses determined during qualification testing are in steps of 0.5 mm and for a given span mark can vary slightly between manufacturers (a thin, strong panel may perform better than a thick, weaker, less stiff, panel). Panels are available in 1220 mm x 2440 mm (4'x8') sheets or “cut to size” dimensions. For industrial applications larger sizes up to 2440 mm x 7320 mm (8'x24') are available by special order. Some new mills manufacture master panels up to 3660 m x 7320 mm (12'x24').

STRUCTURAL PANEL PRODUCTS AS USED IN CONSTRUCTION Plywood, OSB and waferboard have a record of successful use in housing, small buildings and large buildings where the services of structural design engineers are required. In addition, plywood and OSB are frequently used in horizontal (floor type) and vertical (wall type) structural components to resist the horizontal forces generated by wind and earthquake forces. These designs are based on the plywood, OSB and waferboard products we have been discussing and on design values and criteria found in the CSA standard, CSA O86.194 “Engineering Design in Wood (Limit States Design”. As the design properties for these products should only be used by design professionals this chapter will not discuss them further. However, as we discussed extensively in the previous chapter, Part 9 “Housing and Small Buildings” of

THICKNESS OF SUBFLOOR Maximum Minimum Thickness (mm) Spacing OSB, O-1 Plywood of Grade OSB, O-2 Supports Waferboard, Grade (in.) R-1 Grade 16 15.5 15.9 19.2 15.5 15.9 24 18.5 19.0 Materials conform to: CSA O121, CSA O151, CSA O153 or CSA O437.0.

the National Building Code of Canada contains a number of tables that identify a range of product options that can be used under specified conditions. This section focuses on this NBCC tabular type of information. Again, some jurisdictions may have adopted other similar types of tables for use in their area. Be sure to check with your local building official to identify what tables are acceptable in your area. FLOOR SHEATHING There are two basic types of floor panels you will sell. Double-layer floor construction is where rough subfloor sheathing is laid over the floor frame. Underlayment is then laid over the subflooring to provide a smooth, solid surface for finish flooring material. Single-layer floor construction is a panel that is filled on the face side and serves as both subfloor and underlayment. Be sure to ask your customers which type of finished flooring material they plan to use. Then make sure that the surface of the panel you are going to sell them is compatible with their finished flooring material. For example, your customer will not want a panel with a rough surface or small openings on the surface ply if they are planning to use a resilient flooring material. When installing floor sheathing it is important that panels be installed with the surface grain (or surface fibre orientations)—generally the long panel dimensions—at right angles to the joists. And the panel joints parallel to the floor joists should be staggered. Remind your customer of these construction details.

RATING FOR SUBFLOOR Maximum Panel Mark Spacing Used with of Panel-Type Subfloor Supports Underlay (in.) 16 1F16 2F16 19.2 1F20 2F20 24 1F24 2F24 Materials conform to CSA O325.

For most floor sheathing applications it is also a requirement that the joints of the subfloor that are not resting directly on a floor joist should be supported on 2x2 blocking fitted between the joists or that the edges of the subfloor panels are T&G.

EXAMPLES OF T&G PROFILES

Underlay panels are specially manufactured for the use intended and will be at least 6 mm (1/4") thick. The panels should have an appropriate certification mark or CCMC product registration mark identifying the intended use. The minimum thicknesses of plywood, OSB and waferboard subfloor and, the rating for subfloor are identified in the tables at the top of this page. ROOF SHEATHING Roof sheathing is applied over roof trusses or rafters and provides a nailing base for the roof covering materials. The orientation of the panels should be as that identified for floor sheathing. The thickness of the panels depends to some extent on the spacing of the supporting members and whether or not the edges of the panels are supported. To prevent damage to the roof covering the joints perpendicular to the framing members should be H-CLIPS supported by use of a T&G panel (where the panel is thick enough to allow the use of a T&G profile), 2x2 blocking (nailed between the framing members) or by metal H-clips. The minimum thicknesses of plywood, OSB and waferboard roof sheathing and the rating for roof sheathing are identified in the two tables on the next page.

THICKNESS OF ROOF SHEATHING Minimum Thickness (mm) OSB, O-1 Grade and Waferboard, R-1 Plywood and OSB, O-2 Grade Grade Edges Supported Edges Unsupported Edges Supported Edges Unsupported 12 7.5 7.5 9.5 9.5 16 7.5 9.5 9.5 11.1 24 9.5 12.5 11.1 12.7 Materials conform to: CSA O121, CSA O151, CSA O153 or CSA O437.0. Maximum Spacing of Supports (in.)

RATING FOR ROOF SHEATHING Maximum Panel Mark Spacing of Edges Edges Supports Supported Unsupported (in.) 16 2R16 1R16 19.2 2R20 1R20 24 2R24 1R24 Materials conform to CSA O325.

Two additional comments before leaving roof sheathing. Follow the thickness/rating guidelines as discussed but also be conservative. If the rafter spacing is close to the limit, sell the next thicker panel. Also remind your customer that a common mistake builders make when applying roof sheathing is to butt the panels tightly together. 1 Remind them to gap the panels /8". WALL SHEATHING Wall sheathing is required when the exterior cladding requires intermediate fastening between supports or if the exterior cladding requires solid backing. The thicknesses and ratings for wood based panel products are identified below.

THICKNESS OF WALL SHEATHING Minimum Thickness (mm) Type of With supports With supports Sheathing 16 in. o/c 24 in. o/c Plywood 6.0 7.5 Materials conform to: CSA O121, CSA O151, CSA O153.

OTHER STRUCTURAL USES UNDERLAYMENT As discussed previously, underlayment grades of plywood have a solid, touch sanded surface with a special inner-ply construction to resist dents and punctures from concentrated loads. Underlayment can be used under carpet, but is the only kind of softwood plywood underlayment that should be used under resilient flooring. OVERLAID PLYWOOD Softwood plywood may be manufactured with non-wood veneer overlays which improve the appearance and durability of the panel. The overlays of fibre or resin impregnated sheet material are bonded to the face plies of the plywood by heat and pressure. This process seals the overlay to the wood to form an inseparable bond as strong as the wood itself. The resin content of the overlay determines whether the final product is called Medium (MDO) or High (HDO) Density Overlaid plywood. The characteristics of the two types of overlaid plywood are as follows: M D O has a resin impregnated face with a smooth uniform surface intended for high quality paint finishes. Some evidence of the underlying grain may eventually appear. The overlay is most often produced in a natural buff colour.

RATING FOR WALL SHEATHING Maximum Spacing of Supports (in.) 12 19.2 24 Materials conform to CSA O325.0.

Panel Mark W16 W20 W24

H D O has a resin impregnated face which is hard, smooth and chemically resistant. The overlay is usually produced in a whitish semiopaque colour but other colours may be used by manufacturers for identification. CONCRETE FORM Three types of panels are used for concrete forming: sanded, unsanded and speciality grades with resin fibre overlays. In addition, these panels are generally available with a factory applied release agent. If your store stocks concrete form panels, be sure to ask your supplier for the appropriate product literature.

PERMANENT WOOD FOUNDATION There is one additional and major structural use of plywood in housing and small buildings—permanent wood foundations (PWFs). A permanent wood foundation basically is stud walls framed in the ground with a few important differences. First, as shown in the figure below, both the framing and the plywood sheathing is pressure treated to 0.60 retention, or about 50% more preservative than the typical treated fence post you sell (with a 30-year guarantee). The treated material is marked with a certification mark as shown below.

A TYPICAL CONCRETE FORM SYSTEM REPRESENTATIVE PWF CERTIFICATION MARK

PERMANENT WOOD FOUNDATIONS

Second, the PWF system is engineered to withstand soil pressures higher than any abovegrade stud wall ever had to withstand. Third, the PWF system includes a drainage system much more efficient than the average system used with a concrete foundation. The PWF system offers several advantages over a concrete basement. It is easier and faster to build. Since it doesn’t require a concrete subcontractor, it is easier to schedule for general contractors who have their own framing crews. A PWF basement is easy to finish as framing is already in place and can be insulated without taking away living space. It is accepted by most building codes, mortgage and insurance companies. The NBCC requires that PWFs be designed under Part 4 “Structural Design” or if built as a Part 9 building then it needs to follow the requirements of the CSA standard CAN/CSA S406 “Construction of Preserved Wood Foundations”. If your store stocks PWF treated material you should obtain additional literature from agencies providing such information. Two of these agencies are the Canadian Wood Council and CanPly.

HARDWOOD PLYWOOD Hardwood plywood is very different from softwood plywood, OSB and waferboard in that there are two distinctly different uses of hardwood plywood: general construction and industrial markets; and, decorative markets. The information in this section is based on information generally available from the Canadian Wood Council and the Canadian Hardwood Plywood & Veneer Association (CHPVA). GENERAL CONSTRUCTION AND INDUSTRIAL MARKETS Products manufactured for the general construction market are typically manufactured to CSA O115-M “Hardwood and Decorative Plywood” and are accepted for use in construction on the basis of the a CCMC’s product registration system. A major construction use of hardwood plywood is that of the underlay panel.

Products for industrial uses are generally manufactured to either the CSA O115 standard or to a “standard” developed as a result of a special “supplier/buyer” arrangement. DECORATIVE MARKETS Decorative products have historically been manufactured to either CSA O115-M or manufactured to meet specific customer needs. To this end the Canadian Hardwood & Veneer Association (CHVPA) has recently developed and endorsed “voluntary” grading rules for Canadian hardwood plywood. CHPVA LOGO

The purpose of the CHPVA rules is to maintain uniform standards of grading and marking for decorative and industrial hardwood plywood, made primarily with hardwood veneer and decorative plywood with certain softwood veneer faces, produced in Canada for the general distribution market. These grading rules do not specify criteria for the manufacturing of hardwood plywood, but define the grades and their characteristics. It is important to recognize that the existence of the CHPVA rules does not preclude the use of proprietary grades, arrived at and agreed upon between buyer and seller. So, if your store stocks hardwood plywood, it is important that you obtain and review the literature available from your supplier. In addition, hardwood panels are frequently imported. Foreign manufacturers usually grade their products on the bases of their manufacturing preferences. For example, Finnish birch plywood is graded under an entirely different grading system that was developed to reflect their manufacturing practices and range of end uses. Rather than basing veneer grades on a strictly visual basis the CHPVA rules have been developed on the basis of considering both the veneer manufacturing process and visual quality of the resulting veneer. Therefore, before briefly reviewing some limited grade information, let’s

look at the hardwood plywood manufacturing processes.

which the veneer for hardwood plywood is removed from the log. These methods and the resulting veneer products are shown below.

Veneer Slicing The method by which the veneer is removed from the log affects the grain pattern and thus the appearance of the hardwood panels. Logs of the same species will have markedly different grain patterns depending on the veneer cutting method. There are five principal methods by

Veneer Matching Hardwood plywood panels which have been matched are used where a top quality appearance for architectural woodwork. Veneers made by slicing can be arranged in a matched pattern to give attractive regular patterns.

METHODS OF VENEER SLICING FOR HARDWOOD PLYWOOD

Rotary cutting - The log is mounted centrally the lathe and turned against a razor sharp blade. It is peeled into long wide sheets, like an unwinding roll of paper. This method produces veneers with widely varied grain patterns.

Flat slicing - A very distinctive light, variegated pattern similar to that of sawn lumber is produced by flat slicing. The half log (flitch) is mounted heart side flat against the flitch table. Slicing is done parallel to a line through its centre.

Half round slicing - This cut produces veneers showing characteristics of both rotary and plain sliced veneers. A variation of rotary cutting, segments of flitches of the log are mounted off-centre on the lathe resulting in a cut slightly across the annular growth ring.

Quarter slicing - A series of straight stripes results from this method. The quarter log or flitch is mounted on the flitch table so that the growth rings of the log strike the knife at right angles.

Rift cuffing - A rift or comb grain effect is achieved in the various species of oak by cutting at an angle of about 15% off the quartered position. This avoids the flake figure of oak’s medullary rays. These medullary ray cells radiate from the centre like curved spokes.

Designers can choose from the various hardwood species and from the range of figure and grain patterns of each species. Matching is the arrangement of veneer strips of similar or varying grain patterns within a given panel. The most common matching techniques are: Whole piece face - The panel is a single sheet of rotary cut veneer which gives a continuous grain character across the entire sheet. Book match - Every other component within the sheet (a sequence of veneers peeled or sliced from the same log) is turned over like the pages of a book, resulting in identical but opposite patterns. Pleasing match - Components are matched by colour similarity rather than by grain characteristic. Slip match - Adjacent veneer sheets are joined side by side (same ends up) resulting In a uniform grain pattern. U n m a t c h e d - Components of veneer are assembled with no particular order to grain pattern matchings. This results in a random pattern.

Special match - Other veneer matching arrangements are sometimes used for special effect. Some matching patterns are: herringbone, diamond, reverse diamond, box, sunburst and others. Veneer selections for such patterns are best made by the specifier in the manufacturer’s showroom. Hardwood Plywood Cores Since hardwood plywood is used mostly for interior finish applications, stability and the ability to take fasteners are as often as important as appearance. Hardwood plywood in made with various core materials: • veneer core, • multiply veneer core, • particleboard or MDF core, • lumber core, or • lumber core with banding or railing. The most common (and generally least expensive) is a standard 3- or 5-ply veneer core. Panels up to 1/2" thick are generally made with three plies; 1/2" and thicker panels are made with five plies. Veneer cores are fine for most applications, but may warp and may not hold fasteners as well as other cores.

SOME SLICED VENEER PATTERNS FOR CANADIAN HARDWOOD PLYWOOD

Multiply veneer cores have thinner veneers. The panel is often made up of 9 or more veneers, which makes it less likely to warp.

The most common type sold in lumberyards and home centres is made with “water resistant” glue and is considered as an interior panel.

Particleboard and MDF core hardwood plywood is used primarily in cabinet construction. The core makes the panel less expensive, while providing greater stability than plywood manufactured using veneer cores.

Some other panels may be made with a glue that is only rated as “moisture resistant” and the panels are recommended for interior use. Fortunately such panels are not common in home centres. But again be aware that such panels exist.

Lumber core plywood is used mainly for custom cabinetry. It combines exceptional stability with the ability to hold fastener better than any other type of plywood. The cores are made of wood blocks, selected and sorted into three grades: clear, sound and regular. Lumber core plywood also may be banded with veneer, or railed with solid strips of hardwood. In addition to the above, other materials and manufacturing procedures may be used for cores of hardwood plywood. Glue Types Hardwood plywood may be manufactured with various types of glue and different specifications in core veneers and construction, to produce panels that are approved for exterior or interior use. It is important that you seek this information from your hardwood plywood suppliers and that you are familiar with the terminology used when describing glue lines and panel end use. The most weatherproof panel and glue line is suitable for permanent weather exposure. Other panels are made with a fully waterproof glue, but, due to the grades of material used in the cores, are recommended for only limited weather exposure. Hence, the panel may be referenced as “exterior type glue” but the panel itself suited only to limited exposure to the weather.

Grades of Canadian Hardwood Plywood Some softwood plywood is graded under hardwood rules—knotty panels in white pine and western red cedar, vertical grain Douglas fir and hemlock—but only if it is manufactured for decorative applications such as panelling and cabinets. Hardwood plywood rules appear to be complex, but the reason is simple: plywood graded under the hardwood rules is rarely used in general construction. Hardwood and decorative plywood is used in finish applications (such as cabinets and furniture) where appearance and stability are very important and engineered structural properties are not a major factor. Hence, it is graded according to its intended use. The good news on all hardwood and decorative plywood is that you don’t have to worry about hidden structural characteristics. The grading system basically says, if it looks good, it’s great, if it doesn’t look so good, it’s not so great. Canadian hardwood plywoods are manufactured and graded in accordance with the Canadian Hardwood Plywood Association’s “Official grading Rules for Canadian Hardwood Plywood.”

SOME EXAMPLES OF HARDWOOD PLYWOOD CORES

Three-Ply Veneer Core Construction

Five-Ply Veneer Core Construction

Multi-Ply Veneer Core Construction

For example: Veneers for hardwood plywood are graded based on minimum characteristics for face and back veneers. The “face” is the better side of a panel where the outer sides are different and either side of a panel where the outer sides are the same. Face grades are designated AA, A, B, C, D and E (AA is the best quality and E the lowest). The “back” is the side of the panel with the lower grade where the outer sides are different. Back grades are designated 1, 2, 3 and 4 (1 is the best and 4 the lowest). The characteristics of face grades differ slightly depending on the species and the method of veneer cutting used. In general, the better quality face grades have the following characteristics and uses:

woodwork where a superior appearance is required. A - Slight colour variation, slight imperfections 3 and knots to about 4.8 mm ( /16") permitted, used for good quality cabinetry and architectural woodwork. B - Some colour variation, imperfections and 3 knots to about 4.8 mm ( /16") permitted, used for cabinetry and woodwork where the product is less visually exposed or where an opaque finish is to be used. There are many grades, veneers, patterns and panel types for hardwood plywood. Be sure you ask your suppliers for their current literature for the hardwood panels your store stocks. PREFINISHED PANELLING

A A - Slight colour variation, only slight imperfections permitted, highest quality, used for high quality cabinetry and architectural

Information on prefinished panelling is in the Interior Surfaces chapter.

GLOSSARY FOR WOOD BASED PANEL PRODUCTS (The text contains more common panel terms.)

AIS - Abbreviation for asphalt impregnated sheathing. A fibreboard product used for exterior wall sheathing. It contains asphalt mixed into the fibres to assist in improving weatherability. Butt Joint - The joint formed when two panels meet but do not overlap. Chamfer - The flat surface left when cutting off the square edge of a panel or lumber. Cleaned and Sized - A light surface mechanical process that removes material form the surface to provide an even surface and a panel of uniform thickness. Composite - Made up of several items. C o r e - In a 3-ply panel, the innermost part contained between the surfaces. In 5-ply, the innermost ply contained between the cross bands. Crossband - The core veneers at right angles to the face. D e l a m i n a t i o n - Veneer plies or OSB and waferboard wafers coming apart. D l Y e r - Abbreviation for do-it-yourselfer. Commonly a person not a carpenter, but who will personally install the building products he or she buys. Embossed - Surface treatment where heat and pressure are applied to give a surface the look and texture desired. Exterior Type - Plywood made with 100% waterproof glue and containing limited veneer grades. All Canadian plywood manufactured for construction use is exterior type. F i b r e b o a r d - Wood products made by chemically breaking wood down to basic components and then adding water and chemicals to remake it. Hardboard and AIS are two examples.

Glulam - Short for glued laminated beam. These are made of several layers of “lumber” glued together in layers to form one structural piece. Interior Type - Moisture resistant glue is used to make this plywood, rather than 100% exterior glue. Interior type also permits lower grade veneers. Lumber Core - The inner part of a wood veneered product that has lumber strips rather than more plywood veneers. Non-certified - Plywood not certified by an accepted agency as meeting the appropriate standards. Non-certified plywood is not accepted by building codes and some other organizations. Panels may bear the mark of the manufacturer, but this is not a substitute for an accepted certifying agency grade stamp. O & ES - Abbreviation for oiled and edge sealed, a process done to plywood concrete form panels. Oriented Strand Board - A structural wood panel made from reconstituted wood strands 3 approximately /8"x21/2" which have mechanically been lined up to face approximately the same direction. O v e r l a i d - Plywood with factory applied surface(s) of resin treated fibre, aluminum, or other non-wood veneer product. Perforated Hardboard - Hardboard with a regular pattern of holes. Performance Rated Panels - Panels designed to perform to certain specified end uses. The other choice would be panels rated by their appearance. Plywood - A panel made from wood veneers laid in 3 or more layers, usually with each layer at right angles to adjoining layers. Reconstituted - To remake by adding water and possibly other chemicals.

GLOSSARY FOR WOOD BASED PANEL PRODUCTS (cont.) Sanded Panels - Factory sanded for use where appearance and/or smoothness is important.

Touch-Sanded Panels - A light surface sanding process that removes material form the surface to provide a smooth surface and a panel of uniform thickness.

Sandwich Panel - Layered construction with plywood as the outer surfaces and the inner core being a low strength product such as beadboard, corrugated cardboard, etc.

U n d e r l a y m e n t - Panels applied over subflooring, or as the only panel in a single-floor system. Care must be taken to use panels appropriate for the final floor.

Solid Core - The inner plywood cores are free of gaps.

Veneer - A thin sheet of wood, placed in layers to make plywood.

Span Rating - A rating on structural panels that identifies the permissible distances between supports.

W a f e r b o a r d - A panel made from wafers approximately 3" square, bonded with resins under heat and pressure.

Stressed-Skin Panel - Panels glued to framing members making an engineered structural panel for use as roof or floor panels. Together the products have greater strength than if alone.

Wood Based Panel Products - Panels, usually 4'x8', but larger and smaller, that have been professionally designed to perform to certain standards. These panels are made from wood that is peeled from a log, or chopped up, or wood chemically broken down and remade.

Structural Particleboard - Panels made of small wood particles about sawdust size and slightly larger, arranged in layers according to particle size.

HOW TO SELL WOOD BASED PANEL PRODUCTS Panel products are more “commodity” items than impulse or “attractive” items. They are usually a hidden part of the finished product. Yet it is important that the customer takes home the right product for the job. Basically your selling to the DIYer will be raw use of product knowledge. Ask enough questions so you can recommend the proper panel. Of course you will want to “suggestion

sell” the appropriate items that may go with a “panel” purchase. You can do that with confidence after asking questions so you know what they are doing. A customer who can tell you have knowledge of the basic items, such as lumber and plywood or other panel products that go in a project, is likely to trust you to advise them on the rest of the project also.

CANADIAN IMPERIAL AND METRIC MEASUREMENTS Canadians generally measurement units.

use

a

mixture

measurement systems frequently results in many product manufacturers providing information using both systems. Unfortunately, the approaches used in presenting the “converted” measurements are not consistent. Some information is based on “exact” conversion measurements whereas other information is based on “rounded” measurements.

of

Liquid volumes are typically based on the metric (SI) system. Temperatures and distances are commonly specified using metric terminology. Weights, depending on the type of product, use either the metric or Canadian Imperial system. Lengths and dimensions of construction products, particularly for residential use, are generally in Canadian Imperial measurements.

From your perspective and in communicating with your customer it is important to recognize that in some instances the exact conversion is necessary and in other instances a more “rounded” conversion is appropriate.

Canadian building codes are written using metric units. But the construction trades, particularly those in residential construction, typically use the Canadian Imperial system. This mixture of

CONVERSION FACTORS 1 inch (in.) 1 foot (ft.) 1 yard (yd.)

= = =

25.4 mm 0.3048 m 0.9144 m

1 fluid ounce - US (oz.) 1 fluid ounce - Canadian (oz.) 1 gallon - US (gal.) 1 gallon - Canadian (gal.)

= = = =

0.0296 L 0.0284 L 3.785 L 4.546 L

1 ounce - avoirdupois (oz.) 1 pound - avoirdupois (lb.)

= =

28.35 g 0.454 kg

1 pound per square inch (psi) 1 pound per square foot (psf)

= =

6.895 kN/m 0.04788 kPa

2

Celsius temperature = (Fahrenheit temperature - 32) / 1.8

SOME TYPICAL MEASUREMENTS FOR WOOD BASED PANEL PRODUCTS (“rounded” conversions) Length

Length

in.

mm

in.

mm

ft.

m

1

3.2

12

305

4

1.22

1

6.4

16

406

8

2.44

3

9.5

19.2

488

10

3.05

1

12.7

24

610

12

3.66

5

15.9

3

19.1

/8 /4 /8 /2 /8 /4

7

22

Length

/8

22.2

1

25.4

Note: Always consult your provincial and local codes

B3 WOOD BASED PANEL PRODUCTS

PANEL PRODUCTS IN YOUR STORE “In Your Store” is a worksheet where you apply the knowledge you have learned in this chapter to the products you stock in your store. You may be able to find the answers on your own, or you may want to ask some of the people you work with for help. There are no test questions on this information, as the answers vary with location and local custom. Do not send these answers in for correcting. This is a worksheet to help you get more familiar with your store. It becomes a reference tool for you to review when you need a refresher about what your store stocks. DIRECTIONS: Take your copy of this page from your test package. Fill out the blanks as appropriate for your situation. Sometimes more or less information could be entered. The object of the exercise is not to fill in blanks, but to learn more about the products covered in this chapter, as applied to the store you work in. So just use this exercise as a guide. What is commonly used in your area for: floor sheathing? roof sheathing? wall sheathing? What is commonly used as underlayment in your area under: carpet? vinyl? List the sizes, thicknesses, type, face, etc., as appropriate, for the panels you stock. Structural panels: Performance Rated Panels: Floor Floor Roof

Roof

Wall

Wall

Other Sanded plywood Hardwood plywood Standard and/or tempered hardboard Particleboard Fibreboard Notes:

ACKNOWLEDGEMENTS

■ The course was first developed by the North American Retail Hardware Association (NRHA) and the Home Center Institute (HCI) under the direction of a project coordinator and a number of authors. Several U.S. based companies provided industry specific information. This second Canadian Edition of the ACHR is based on NRHA/HCI’s 14th Edition. It has been extensively modified and rewritten with the help of Carl R. Wilson & Associates Ltd. (CRWAL) so as to reflect Canadian products and construction practices. We also acknowledge the many Canadian organizations and companies that provided information for this Canadian edition of the Advanced Course in Hardware Retailing (ACHR) and the Building Material Product Knowledge Course (BMPK). Because local codes and regulations vary greatly, you are reminded to check with local experts and authorities on which codes, regulations and practices apply in your area. Copyright© 2004 by NRHA. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or any system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior written permission of the publisher.

Though the information in this course is intended to be accurate and useful, the authors, editors, publishers, NRHA and CRWAL and their directors, officers, agents and employees will not be liable for any damage whatsoever that might occur from any use of this material.

NOTE: ALWAYS CONSULT YOUR PROVINCIAL AND LOCAL CODES