Section Contents

APA Plywood Panel Grades for Specific Applications

There are two ways to identify APA plywood panels:

  1. The type of veneer grade identified on the trademark refers to the grades on face and back of the panel e.g. A-C or B-B.
  2. Information given here on the panel’s end use application such as:
APA Rated Sheathing APA Rated Sturd-I-Floor
APA A-B APA A-C
APA B-B APA B-C
APA C-C Plugged APA C-D Plugged
APA 303 Siding APA T1-11®
APA High Density Overlay (HDO) APA Medium Density Overlay (MDO)

APA Rated Sheathing

Unsanded panels specially designed for structural subfloor decking, wall and roof applications.
Other significant uses are shipping crates, pallets & pallet bins, shelving and partitions, as well as a range of industrial applications.

 

Performance
Category

 

Recommended Thickness
Label
(Figure in brackets is mm equivalent)

 

Typical APA
Trademark with Exposure Durability
Classification

 

Veneer Grades

 

Face

 

Inner

 

Back

3/8
15/32
1/2
19/32
5/8
23/32
3/4

0.354 IN (8.99)
0.451 IN (11.46)
0.483 IN (12.27)
0.578 IN (14.68)
0.609 IN (15.48)
0.703 IN (17.86)
0.734 IN (18.65)

 

Exposure 1   

C

D

D

Exterior

C

C

C

APA Rated Sturd-I-Floor

Specially designed floor panel with smooth surface for carpet and high impact and concentrated load resistance. Available with square or tongue-and-grooved edges.  Normally touch sanded.  Plywood Sturd-I-Floor may also be available with a sanded face.

 

Performance
Category

 

Recommended Thickness
Label
(Figure in brackets is mm equivalent)

 

Typical APA
Trademark with Exposure Durability
Classification

 

Veneer Grades

 

Face

 

Inner

 

Back

19/32
5/8
23/32
3/4
1-1/8

0.578 IN (14.68)
0.609 IN (15.48)
0.703 IN (17.86)
0.734 IN (18.65)
1.091 IN (27.72)

 

Exposure 1

C
plugged

C1,D

D

 

Exterior

C plugged

C1

C

Note:
Special knothole size restrictions apply to ply adjacent to face to resist indentation from concentrated loads

APA A-B

Provides two solid sanded surfaces for applications where appearance of one side is less important than the other such as high appearance hoarding, signboards, shipping containers, shelving, ducts and cabinets.

 

Performance
Category

 

Recommended Thickness
Label
(Figure in brackets is mm equivalent)

 

Typical APA
Trademark with Exposure Durability
Classification

 

Veneer Grades

 

Face

 

Inner

 

Back

1/4
11/32
3/8
15/32
1/2
19/32
5/8
23/32
3/4

0.234 IN (5.95)
0.328 IN (8.33)
0.359 IN (9.12)
0.453 IN (11.51)
0.484 IN (12.30)
0.578 IN (14.68)
0.609 IN (15.48)
0.703 IN (17.86)
0.734 IN (18.65)

 

Exposure 1

A

D

B

Exterior

A

C

B

APA A-C

For exterior applications where the appearance of only one sanded side is important, such as soffit boards, high quality appearance hoarding, lorry cargo space linings, farm buildings and commercial refrigerators.

 

Performance
Category

 

Recommended Thickness
Label
(Figure in brackets is mm equivalent)

 

Typical APA
Trademark with Exposure Durability
Classification

 

Veneer Grades

 

Face

 

Inner

 

Back

1/4
11/32
3/8
15/32
1/2
19/32
5/8
23/32
3/4

0.234 IN (5.95)
0.328 IN (8.33)
0.359 IN (9.12)
0.453 IN (11.51)
0.484 IN (12.30)
0.578 IN (14.68)
0.609 IN (15.48)
0.703 IN (17.86)
0.734 IN (18.65)

 

Exterior

A

C

C

APA B-B

General purpose utility panel with two solid sanded sides.  With B-B Exterior both sides can be used for concrete forming (Plyform) to double panel usage.

 

Performance
Category

 

Recommended Thickness
Label
(Figure in brackets is mm equivalent)

 

Typical APA
Trademark with Exposure Durability
Classification

 

Veneer Grades

 

Face

 

Inner

 

Back

1/4
11/32
3/8
15/32
1/2
19/32
5/8
23/32
3/4

0.234 IN (5.95)
0.328 IN (8.33)
0.359 IN (9.13)
0.453 IN (11.51)
0.484 IN (12.30)
0.578 IN (14.68)
0.609 IN (15.48)
0.703 IN (17.86)
0.734 IN (18.65)

Exposure 1

B

D

B

 

Exterior

B

C

B

APA B-C

Utility panel with B-grade veneer face, sanded smooth.  Suitable for use on farm service and non-permanent buildings, cargo linings for rail cars and lorries, concrete formwork and agricultural bins.

 

Performance
Category

 

Recommended Thickness
Label
(Figure in brackets is mm equivalent)

 

Typical APA
Trademark with Exposure Durability
Classification

 

Veneer Grades

 

Face

 

Inner

 

Back

1/4
11/32
3/8
15/32
1/2
19/32
5/8
23/32
3/4

0.234 IN (5.95)
0.328 IN (8.33)
0.359 IN (9.12)
0.453 IN (11.51)
0.484 IN (12.30)
0.578 IN (14.68)
0.609 IN (15.48)
0.703 IN (17.86)
0.734 IN (18.65)

 

Exterior

B

C

C

APA C-C Plugged

Provides smooth surface for applications of carpet with high impact and concentrated load resistance.  For floor decking, refrigerated storage rooms, pallet bins, railcar and lorry floors and lining of their cargo areas,  soffit, tile backing, concrete formwork where smooth finish is not essential and other similar uses where continuous or severe moisture may be present.

 

Performance
Category

 

Recommended Thickness
Label
(Figure in brackets is mm equivalent)

 

Typical APA
Trademark with Exposure Durability
Classification

      
       Veneer Grades
Face     Inner   Back

3/8
1/2
19/32
5/8
23/32
3/4

0.354 IN (8.99)
0.483 IN (12.27)
0.578 IN (14.68)
0.609 IN (15.48)
0.703 IN (17.86)
0.734 IN (18.65)

 

Exterior

C
Plugged

C

C

APA C-D Plugged

For built-in storage units, walls and ceiling tile backing, cable reels, separator boards and other interior or protected applications.  Not intended for formwork, nor as a substitute for APA Rated Sturd-I-Floor because it lacks the necessary puncture resistance.

 

Performance
Category

 

Recommended Thickness
Label
(Figure in brackets is mm equivalent)

 

Typical APA
Trademark with Exposure Durability
Classification

      
       Veneer Grades
   Face      Inner  Back

3/8
1/2
19/32
5/8
23/32
3/4

0.354 IN (8.99)
0.483 IN (12.27)
0.578 IN (14.68)
0.609 IN (15.48)
0.703 IN (17.86)
0.734 IN (18.65)

 

Exposure 1

C
Plugged

D

D

APA 303 Siding

Textured, grooved or overlaid exterior panels used for cladding or fencing and made exclusively by APA member manufacturers.  Available in a variety of wood species.  When applied directly or through blocking to studs, the panels possess sufficient strength and shear wall racking resistance to eliminate the need for diagonal bracing.

 

Performance
Category

 

Recommended Thickness
Label
(Figure in brackets is mm equivalent)

 

Typical APA
Trademark with Exposure Durability
Classification

      
       Veneer Grades

 

Face

 

Inner

 

Back

11/32
3/8
15/32
1/2
19/32
5/8

0.322 IN (8.18)
0.354 IN (8.99)
0.451 IN (11.46)
0.483 IN (12.27)
0.578 IN (14.68)
0.609 IN (15.48)

 

Exterior

When 303-OL face veneer is B

Faces of other grades per 303 manufacturing specification

C

C

APA T1-11

This is a special APA 303 Siding (cladding) panel with grooves 6.4 mm (1/4”) deep, 9.5 mm (3/8”) wide, spaced 100 mm (4”) or 200 mm (8”) on centre or with other spacings in special order.  Available as unsanded, textured and MDO finish in a variety of species.

 

Performance
Category

 

Recommended Thickness
Label
(Figure in brackets is mm equivalent)

 

Typical APA
Trademark with Exposure Durability
Classification

      
       Veneer Grades
   Face Inner  Back  

19/32
5/8

0.578 IN (14.68)
0.609 IN (15.48)

Exterior

When 303-OL face veneer is B

Faces of other grades per 303 manufacturing specification

C

C

APA High Density Overlay (HDO)

Panel face and back coated with hard, semi-opaque resin fibre overlay highly resistant to abrasion.  For concrete forms, cabinets, countertops, laboratory bench tops, signs, industrial tanks.  Also available with skid-resistant screen grid surface suitable for pedestrian walkways.

 

Performance
Category

 

Recommended Thickness
Label
(Figure in brackets is mm equivalent)

 

Typical APA
Trademark with Exposure Durability
Classification

      
       Veneer Grades
   Face     
Inner
   Back

3/8
1/2
5/8
3/4

0.354 IN (8.99)
0.483 IN (12.27)
0.609 IN (15.48)
0.734 IN (18.65)

Exterior

 A  or  B

C2  Plugged

A  or B

Note:
May have C centre if five or more plies

 APA Medium Density Overlay (MDO)

One or both surfaces coated with smooth, opaque resin-fibre overlay, ideal base for paint, indoors or outdoors.  Suitable for shelving, factory work surfaces, panelling, signs, built-in storage units.  Specially manufactured MDO panels may also be used for concrete forming.  Also available as APA 303 Siding.

 

Performance
Category

 

Recommended Thickness
Label
(Figure in brackets is mm equivalent)

 

Typical APA
Trademark with Exposure Durability
Classification

 

Veneer Grades

 

Face

 

Inner

 

Back

11/32
3/8
15/32
1/2
19/32
5/8
23/32
3/4

0.322 IN (8.18)
0.354 IN (8.99)
0.451 IN (11.46)
0.483 IN (12.27)
0.578 IN (14.68)
0.609 IN (15.48)
0.703 IN (17.86)
0.734 IN (18.65)

 

Exterior

B

C

B or C

APA in Europe Wizard

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All Questions OSBPlywood

What are the main changes to the FSC Chain of Custody Certification standard?

Download What’s New in FSC revised COC standard.   Also, the previous FSC compulsory verification programme has been replaced by a due diligence protocol with a new risk assessment system. Learn more.  North American good forestation practice supports the aims of EUTR.  Its sustainably managed forests comply with one or more of the five leading certification agencies responsible for verifying proper forestry practices.

 

Can US Underwriters Laboratories certified EPDs be used for environmental performance ratings under the BREEAM system?

Learn how APA products can count towards a building’s BREEAM rating.  The British Research Establishment and the US Underwriters Laboratories  now recognize each other’s certified EPD making it simpler for APA member mills to gain environmental performance ratings under the BRE Environmental Assessment Method  (BREEAM).

Does APA plywood meet the lowest category (E1) for formaldehyde release without need for further testing?

Under the harmonised European Standard for wood-based panels, EN 13986, Annex B, ‘wood-based panels glued with resins emitting either no formaldehyde or negligible amounts of formaldehyde after production as e.g. isocyanate or phenolic glue’ are to be classified as E1 (the lowest formaldehyde release class) without further testing.

See APA’s guide Formaldehyde and Engineered Wood Products.  APA plywood is designated under the lowest E1 category for formaldehyde release without needing further testing.  APA’s US PS 1 and PS 2 plywood have been tested to EN 717-1 and formaldehyde levels already meet the requirements for the E1 classification limit.

Also see:  Formaldehyde (plywood) and Formaldehyde (OSB).

 

 

Can APA plywood and OSB be used in non-construction applications?

US plywood and OSB are equally effective as sturdy, robust and cost-effective solutions  for non-construction applications – from shelving, site hoardings , protective linings in the cargo bay of delivery vehicles to packaging and furniture.   See APA’s Performance Panels.   Need help to decide what grade or type of panel to use for a specific application? APA’s Industrial Panel Selection Guide (Form T200) is another easy to use resource.

How do I equate product Use Classes with the Service Classes given in Eurocode 5 for the design of buildings using engineered wood products?

See APA’ s guide  to Service Classes and Use Classes. For maximum biological durability, both Service Classes and Use Classes must be considered when specifying US CE-marked panels .  This guide helps you make the right selection.

 

‘Hazard classes’ have been replaced (see updated EN 335:2013) by Use Classes covering plywood and OSB.  They will also cover LVL when the LVL standards have completed their current update.  Use Classes are based on different environmental exposures that can make the panel susceptible to deterioration. , as given in Eurocode 5, are used for assigning  strength values and calculating deformation in load bearing situations.  They are determined by the moisture content of the panel corresponding to the environmental humidity and temperature during service.

How do APA’s member’s products count towards a sustainability assessment for new construction or in refurbishment projects?

The British Research Establishment and the US Underwriters Laboratories  now recognize each other’s certified EPD making it simpler for APA member mills to gain environmental performance ratings under the BRE Environmental Assessment Method  (BREEAM).  This is the UK’s leading and most widely used environmental assessment method for buildings and communities. It sets the standard for best practice in sustainable design and has become the de facto measure used to describe a building’s environmental performance. Learn how APA products can count towards a building’s BREEAM rating.

What is a ‘life cycle stage’ and how do these link to the environmental assessment of whole buildings?

A good starting point is our Green Topics section and  Types of EPD and the five life cycle stages

How do core category rules link with environmental product declarations?

EN 15804:2012 +A1:2013 provides the core Product Category Rules (PCR) for the production of Environmental Product Declarations (EPD) for all construction products and services.  Review with main environmental standards.  For more details see: Core Product Category Rules (PCR) for Products and Services. 

Whose responsibility is it to check that wood products being imported into the EU do not originate from illegally sourced timber supplies?

The European Union Timber Regulation (EUTR) puts specific obligations on operators and traders . Operators (or importers) are any (natural or legal) person first placing timber on the EU market. They must maintain records of any traders that they supply timber to.  They must implement a due diligence system to minimise the risk of putting illegal timber or any of its derived products on the market.  Learn more.

Does the EUTR require mills to provide any extra documentation for customs entry into the European Union?

The European Union Timber Regulation (EUTR) puts specific obligations on operators and traders and applies to timber originating in the domestic (EU) market, as well as from third (non-EU) countries such as North America. The information it requires has to be retained for at least five years and be available on request.  See European Timber Regulation.

Must all plywood and OSB panels carry a CE marking?

Manufacturers of wood-based products  covered by either a harmonised European standard (hEN) or a European Technical Assessment (ETA) must apply for CE marking under the 2013 Construction Products Regulation.  See CPR & CE Marking  and our Official Guidelines section.

What is the definition of a construction product under the CPR?

This applies to any product or kit which is produced and placed on the market for incorporation in a permanent manner in construction works or parts thereof and the performance of which has an effect on the performance of the construction works with respect to the basic requirements for construction works.’

Products must clearly display the CE mark and have the correct Declaration of Performance documentation.  For more info: CPR & CE Marking.

What is a Declaration of Performance referred to under the Construction Products Regulation?

Under the CPR, manufacturers wishing to trade in the European market are legally required to set down the levels of performance for any construction product.  They have to be listed in an official document called a Declaration of Performance.

What is the difference between Structural 1 and Exposure 1?

Exposure 1 is a glue bond classification.  It uses the same 100% waterproof glue as exterior panels and refers to a panel’s durability when long delays in construction are expected or when facing high moisture content. For plywood, see  https://apawood-europe.org/products-trademarks/plywood/trademarks/glue-bond/.  For OSB:  https://apawood-europe.org/products-trademarks/osb/trademarks/exposure-durability-classification/

Structural 1 refers to a panel’s superior performance characteristics.  For OSB, see https://apawood-europe.org/products-trademarks/osb/comparable-performance-requirements/

For Structural 1 plywood,  all panels have special improved veneer grades and if manufactured to the American PS1 standard, the veneer grades will be species with a Group 1 strength classification.  See group classification of species.

 

The CE-mark on an APA plywood panel means it conforms to European Standards – but which ones?

Plywood Design Information looks at the plywood grades A-A, A-B, A-C; B-B, B-C; C-C, C-D and the relevant standards that the trademarked panels comply with.

 

I want to use a Rated Sheathing panel for flooring/ roofing application, what info do I need to know?

For plywood, see Span rating.  For OSB, see Span rating. A full range of technical information in under Products and Trademarks.

What extra strength benefits do Structural 1 OSB panels provide over standard Rated Sheathing panels?

OSB Structural I  on an APA trademark indicates that the OSB structural-panel meets the requirements of a Performance Rated panel.  This delivers superior design capacity for these panels over OSB Rated Sheathing and Sturd-I-Floor.  Also see Comparison of Superior Design Capacities for OSB Structural I Sheathing with OSB Rated Sheathing.

What is the difference between a touch-sanded panel and sanded panel?

Veneer in a finished US trademarked plywood panel must conform to one of the six grades listed in the US PS 1-09 standard: N, the highest classification (rarely produced), followed by A, B, C-plugged, C and D.  Non-overlaid APA plywood panels come in three levels of surface finish – sanded, touch-sanded and unsanded.

Also see veneer grades for Popular APA Plywood Panels.

How do APA veneer grades match those given in the European standards

APA has produced two easy to follow guides to help match the grade numbers given on a US finished plywood panel with the requirements of  EN 635-3.

Detailed guide listing permissible defects – with maximum sizes.

Simplified guide to the US PS 1-09 veneer grading rules and appearance grades in EN 635-3 based on the appearance of the surface veneers. Equivalents cannot be exactly compared as two different sets of grading rules apply.

How do I correctly gauge the face appearance a plywood Siding panel?

I want to specify an APA panel for concrete formwork – what do I need to know?

See APA’s comprehensive Concrete Forming Design/Construction Guide for architects, engineers and contractors and the types of APA concrete forming plywood panels.

Are APA panels tongue and grooved on all four edges?

APA panels have a tongue and groove profile on their two long edges.  This eliminates the need for support (blocking) under adjacent panel edges to prevent them from deflecting independently of each other when load is applied.  See Tongue & Groove  (plywood) and Tongue & Groove (OSB).

I am not familiar with the term ‘Sized for Spacing’ – what is its significance?

‘Sized for Spacing’ on APA Rated Sheathing, APA Rated Sturd-I-Floor and APA Rated Siding trademarks indicates that the manufacturer has produced the panel to a size slightly less than the traditional nominal 2440mm (96″) by 1220mm (48″).  It is done to facilitate proper panel spacing during construction.  See Sized for Spacing  (plywood) and Sized for Spacing  (OSB).  For further technical details see Product and Trademarks.

How are Performance Category and thickness related?

Performance Category, Panel Thickness and Span Ratings are key categories that need to be considered together.  See Thickness, Performance Category  (plywood) and Thickness, Performance Category (OSB).

I’d like to know more about a panel’s Span Rating and how it links to thickness.

Plywood: Span rating
OSB: Span rating

What is Span Rating on the APA trademark and why is it important?

Span Rating denotes the maximum recommended centre to centre spacing of supports in inches over which the panel should be placed with its strength axis across two or more supports. Plywood: Span rating.  OSB: Span rating

What is the difference between Exposure 1 and Exterior plywood panels? What are their appropriate uses?

Bond classification relates to moisture resistance of the glue bond and therefore to the structural integrity of the panel.  See glue bond durability classification (plywood) and exposure durability (OSB).

What are the main OSB panels likely to be available in Europe?

See APA’s guide to panel grades  and also info on understanding the trademark.

What are the main plywood panels likely to be available in Europe?

What are the main European standards that I would need to be aware of for OSB panels?

The main standards are: EN 13986 and EN 300.   But also see the other relevant standards for OSB.

What are the main European standards that I would need to be aware of for plywood panels?

The main standards are: EN 13986, EN 636, EN 314, EN 635-3.  And for more details, see EU standards for plywood.