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INTRODUCTION
The EWPAA has for some time been receiving marketplace feedback about the poor performance of low
cost imported underlayment plywood and anecdotal evidence of a significant increase in flooring
failures due to the quality of plywood underlayment. Underlayment plywood is plywood used under
high value strip flooring systems and is usually fixed to a concrete slab with the strip flooring nailed into
the underlayment plywood. The underlayment plywood’s primary role is to provide substrate into
which nails can be fastened however it also fulfils secondary roles in sound attenuation, to stablise the
floor by providing a base which minimises hygroscopic movement and at times may be used as a
structural element of the floor.
Due to the strong marketplace feedback on the poor performance of imported underlayment plywood,
the EWPAA was instructed to purchase a sample of imported underlayment plywood and test any claims
of compliance to Australian Standards and ascertain “fitness for use” in the intended underlayment
application.
To be “fit for use” as flooring underlayment any plywood would need to meet the following criteria.
1.

Bonding Quality - As a minimum, should be Type B as specified in AS/NZS 2754.1 Adhesives for
Plywood (see Table One)

2.

Thickness – Thickness would need to be uniform across the panel to ensure a flat and smooth
floor and mean panel thickness should meet strict limitations.

3.

Formaldehyde – There are currently no limitations for formaldehyde emissions under the
Building Code of Australia, or any mandatory requirements for emission labelling on products,
however as the product is used in confined environments formaldehyde emissions are a serious

potential risk to home occupants should emissions be high.

4.

Lyctid Borer Susceptibility - The product must be free from lyctid susceptible sapwood veneer.
This is not only required to ensure that the product is “fit for use” but is also required under
Queensland and New South Wales State Legislation. Lyctid susceptible sapwood can be treated
against infestation by a recognised preservative.
Note: Plywood complying with Australian Standards AS/NZS 2269 – Structural Plywood or
AS/NZS 2271 – Exterior Plywood automatically meet all the above criteria.

Purchase of Plywood
Product was purchased in the open market in Northern New South Wales by an EWPAA representative.
The EWPAA representative specifically requested a plywood product for use as underlayment for a strip
floor. The product was represented by the merchant as “the stuff everyone uses for underlayment”.
Refer Plates 1a and 1b.
One sheet of the 15mm imported product was purchased and forwarded to the EWPAA National Testing
Laboratory for testing and analysis.


It should be noted that the sheet purchased did not have any labelling to identify the grade, bond type,
formaldehyde emission class, the manufacturer or country of origin.
The results of tests are as follows:
TESTS TO DETERMINE “FITNESS FOR USE”
1.

Bond Quality and Thickness

Test specimens were extracted from the sample sheet and subjected to the four standard bond
durability tests defined in AS 2754.1 Adhesives for Plywood.

These bond types and their suitable uses are defined in Table One of AS 2754.1 which has been
reproduced below.

TABLE 1 – Extract from AS 2754.1
BOND TYPE CLASSIFICATION
Water soak treatment (prior to
testing to Clause 7.2 of AS 2098.2)
Temperature
Time

Bond
Type

Service condition

Adhesive type
(see Note 2)

A

Type A bonded plywood panels can be used in applications involving
extreme long-term exposure to weather or wet or damp conditions
and/or long-term structural performance requirements without
glueline breakdown or glueline creep.
Examples: Structural plywood flooring, highway signs and marine
plywood

Synthetic phenolformaldehyde,
natural
polyphenolformaldehyde or

mixtures thereof

100 C

72 + 1 h
– 0 or
6 h at 200 kPa
steam pressure

B

Type B bonded plywood panels can be used in applications involving
extreme short-term (not more than two years) exposure to weather or
wet or damp conditions and/or short-term structural performance
without glueline breakdown or glueline creep. They can also be used in
applications involving long-term exposure to protected exterior nonstructural environments.
Examples: Concrete formwork, exterior door skins

Melamine-ureaformaldehyde

100 C

6h+5
– 0 min

C

Type C bonded interior plywood panels can be used in non-structural
applications involving full protection from the weather or wet or damp
conditions. They can be used in applications involving long-term

exposure to generally high humidity and short-term exposure to
extremely high humidity.
Examples: Interior panelling in geographical locations which have
prolonged periods of high humidity. Panelling in a bathroom.

Ureaformaldehyde

70 ± 1 C

3h+5
– 0 min

D

Type D bonded plywood panels can be used in non-structural interior
applications fully protected from the weather or wet or damp
conditions. They can be used in interior applications involving longterm exposure to medium humidity with occasional exposure to high
humidity.
Examples: Furniture, interior wall panelling.

Extended ureaformaldehyde

15 C to
20 C

16 h to 24 h

NOTES:
1.
Experience has shown that Type A bonded plywood will withstand complete exposure to the weather for 20 years or maintain its

integrity in structural situations for 50 years without glueline breakdown or glueline creep.
2.
With adhesives or other chemical types, compliance with the test requirements alone would not indicate equal durability, and
confirmation by actual service trials would be required.

The results for bond quality tests are detailed in Appendix A.


These results show that the plywood sheet tested has failed to meet either Type A, B or C bonding
requirements and has only meet requirements for Type D.
As defined in Table One of AS 2754.1, Type D bonded plywood is not suitable for use in applications
where the plywood is subjected to wet or damp conditions or high humidity.
Wet and damp conditions are at times typical for flooring underlayment which is frequently subjected to
wetting when floors are mopped and cleaned. The concrete floor itself can also be a significant source
of moisture when timber flooring is laid over new or green concrete. In such conditions the Type D
bond adhesive will rapidly breakdown and lead to failure of the floor.
As stated previously, in applications where plywood is subject to intermittent wetting over a long period
a Type A or Type B bond glueline is required. There is no doubt that the imported plywood tested will
not provide an extended service life and the floor will fail prematurely. The imported plywood is not
suitable to provide long—term performance and durability.
Thickness results are also detailed in Appendix A. Results of these tests showed thickness to be uniform
and variation from nominal (15mm) thickness is only slight. In regard to the panel tested, thickness
results are very good.
2.

Formaldehyde Emissions

The test results for formaldehyde emissions are detailed in Appendix B. These are very disturbing as
firstly, emissions were extremely high (4.8mg/2) and of more concern the emission class was not
labelled on the panel identifying it as a high emission product.

Formaldehyde has recently been reclassified as a known carcinogenic substance and as a result
Australian plywood standards were updated to require labelling of formaldehyde emissions. Every
plywood sheet complying with Australian Standards must be labelled with the formaldehyde emission
class. However, as no claims have been made by the importer or supplier of the plywood tested of
compliance with Australian Standards, this product has fallen outside of the labelling requirements of
the Australian Standard.
This in itself is a serious issue as failure to identify this product as a high emitter will lead to this product
being used in applications where ventilation is poor and the floor area sufficiently large to cause
formaldehyde to accumulate in the atmosphere to a potentially dangerous level.
The use of this product without any form of labelling is extremely concerning. It is the writer’s opinion,
this product is not “fit for use” and potentially unsafe in unventilated or poorly ventilated applications or
where sensitive individuals may be exposed.
The EWPAA laboratory tests formaldehyde emissions from all certified products manufactured in the
Australasia region.


PLATE 1a – Face of purchased plywood sheet

PLATE 1b – Edge of purchased plywood sheet


By way of comparison all EWPAA certified structural plywood and Type A bond exterior plywood have an
emission class of E0 with a maximum emission of 0.50mg/L. In fact, the average formaldehyde emission
for all structural and Type A exterior plywood products produced by EWPAA certified mills is only
0.26mg/L or half the permitted level and approximate to the natural formaldehyde emission from
timber.
The measured emission from the imported underlayment plywood was 4.8mg/L or approximately 18
times the average emission from EWPAA Certified Structural Plywood.
3.


Lyctid Susceptibility

Lyctid borers attack the sapwood of many hardwood species completely destroying the wood structure.
See Plates 2a and 2b. Softwood species such as radiata pine and hoop pine are immune to attack. Due
to the high risk associated with lyctid attack, it is illegal to market timber products in Queensland and
New South Wales that contain unidentified untreated sapwood of susceptible species.

PLATE 2a – Typical example of damage caused by Lyctid borer


PLATE 2b – Typical example of damage caused by Lyctid borer
The first sign of Lyctid attack is usually the presence of flight or exit holes in the timber product. (See
Plate 3). In the case of strip timber flooring, Lyctid borers commonly chew through the overlaying strip
floor to escape from infested underlayment when mature to reach to the outside environment.

PLATE 3 – Typical damage of flooring due to Flight Holes


The wood species used in the manufacture of the imported underlayment plywood have been identified
by the Queensland Department of Primary Industries and Fisheries (DPI&F). See Appendix C (Sheet 4 in
the DPI report). DPI & F have identified have identified the core veneer species as “Populus spp.” Poplar
is a low density hardwood frequently used by Chinese plywood manufacturers. Poplar is identified in AS
5604 – Timber Natural Durability Ratings as Lyctid susceptible. This requires all sapwood to be
chemically treated to prevent infestations by Lyctid borers. In addition to species identification, the DPI
& F have also performed chemical analysis for the presence of approved insecticides used to treat
against attack by Lyctid borers.
In addition to tests performed by DPI & F, the EWPAA subjected the plywood to the standard test for the
presence of sapwood defined in Appendix A of AS 1604.1 – Specification for Preservative Timber. This
test confirmed the presence of sapwood at a number of locations in the sheet.
The results of tests for Lyctid susceptibility have shown that the species of timber (Poplar) used in the

core veneers is a species susceptible and the presence of sapwood has been confirmed. Chemical
analysis by DPI & F have confirmed that the product has not been chemically treated to prevent Lytcid
attack.
These tests have confirmed that the plywood sheet is susceptible to attack by Lyctid borers.
The sale of the plywood which the EWPAA has tested is actually illegal in the State from which it was
purchased as it does not comply with the New South Wales Timber Marketing Act.
The use of untreated Lyctid susceptible plywood underlayment is absurd as the risks associated with
Lyctid attack far outweigh the cost benefit $2-3m2 in using a low cost imported substitute underlayment
material. Lyctid susceptible underlayment is quite simply not fit for use and it is highly irresponsible of
the material supplier and flooring contractor to use such material.

CONCLUSION
TABLE TWO- SUMMARY OF TEST RESULTS
Product Property

Requirement to be “Fit for Use”

Result of Test

Conclusion

Bond Type

Minimum of Type B

Type D

UNFIT FOR USE

Thickness


Uniform thickness with only small
variation

Uniform thickness

PASSED

Low to medium and branded

Very high and not branded

UNFIT FOR USE

Not susceptible or treated

Untreated susceptible sapwood
is present

UNFIT FOR USE

Formaldehyde
emission
Lyctid Susceptibility


This is a very worrying result with the panel tested failing 3 out of 4 performance requirements to
ensure fitness for use as strip flooring underlayment.
Testing by the EWPAA and DPI & F has confirmed the marketplace feedback received by the EWPAA of
the significant increase in quality issues and premature failure of high value strip floors and flooring

systems due to the substitution of imported underlayment plywood. It is essential that building
designers, specifiers, flooring layers and home owners are urgently made aware of the significant risks
associated with the use of this low cost substitute product.
To ensure that underlayment plywood is “fit for use”.
1.

Request product manufactured in accordance with Australian Standards. Plywood manufactured in
accordance with AS/NZS 2269 – Structural Plywood or AS/NZS 2271 Exterior Plywood are entirely fit
for use. These product standards require that the plywood has the following properties:
1. Manufactured using Type A or Type B adhesives.
2. Thickness is controlled within tight limitations.
3. Formaldehyde emissions are labelled allowing the consumer to readily identify and select low
emission products.
4. The use of Lyctid susceptible timber is prohibited.

2.

Independent Third Party Product Certification. Request underlayment plywood manufactured
under a JAS-ANZ accredited product certification scheme. This ensures that manufacturers claims
of compliance to product standards are independently verified. Suitable products manufactured
under the EWPAA’s JAS-ANZ’s accredited certification scheme will carry the following

certification marks.

Structural Plywood Certification Mark


Exterior - Type A Bond Certification Mark

Exterior – Type B Bond Certification Mark


SIMON DORRIES
FEBRUARY 14, 2008


APPENDIX A
Results of Bond Quality and Thickness
Tests


EW PAA Te st Re por t Re f : 7 / 1 2 / 2 0 0 7 1 2 - 2 6
External Special Samples

Results of Plywood Bond Quality Tests of Samples Recieved 7/12/2007 (Batch 12-26)
Bond Quality

Thickness
Type

Bond

Nom Thick

Plys

Species

Measured

Result


12-26-1-07

ID

Exterior

A Bond

15

11

Other

Sheet 4

14.93

Pass

12-26-2-07

Interior

B Bond

15

11


Other

Sheet 4

14.84

Pass

12-26-3-07

Interior

C Bond

15

11

Other

Sheet 4

14.79

Pass

12-26-4-07

Interior


D Bond

15

11

Other

Sheet 4

14.77

Pass

All thickness values are shown in mm.

Code

Comments

Manufactured

Total Samples : 4

Samples Passed : 1

Bond Ratings
0
0

0
0
8
1
10
4

0
0
1
0
6
6
10
8

Avg

Result

0

0

0

0

0


0

0.00

Fail

0

0

0

0

0

0

0.10

Fail

2

3

2

2


1

2

3.30

Fail

7

6

5

3

6

6

6.50

Pass

Batch Bond Quality Average :

2.48

The bond qualities and thicknesses of the above samples were determined in accordance with AS/NZS 2098.2-2006 (except section 8.1) and AS/NZS 2098.4-2006 respectively. The
minimum and maximum thickness have not been reported.

Regards

Susie Steiger
Auditor

Thursday, 28 February 2008

Plywood House 3 Dunlop Street Newstead Qld Australia | PO Box 2108 Fortitude Valley BC Qld 4006
P: +617 3854 1228 | F: +617 3252 4769 | E: | ABN 34 009 704 901

Page 1 of 1


APPENDIX B
Results of Formaldehyde Emission Tests


EW PAA Te st Re por t Re f : 7 / 1 2 / 2 0 0 7 1 2 - 2 5
External Special Samples

Results of Plywood Formaldehyde Tests of Samples Recieved 7/12/2007 (Batch 12-25)
Sample Description
12-25-2-07

Interior

15 mm

9 ply


Species

Comments

Finish

Other

Sheet 4. This sample was
tested as per normal
conditioning periods.

Finished

Abosorbance
0.667

Emission

E-Class

4.764

E3

Total Samples : 2

Testing has been in accordance with methods outlined in the Australian Standard Test Method’s AS/NZS2098.11 for Plywood or AS/NZS4357.4 for LVL. Measurement uncertainty is
0.035 mg/L. All LVL, I Beam and Formply samples are Edge Treated prior to testing.
Regards


Susie Steiger
Auditor

Thursday, 28 February 20

Plywood House 3 Dunlop Street Newstead Qld Australia | PO Box 2108 Fortitude Valley BC Qld 4006
P: +617 3854 1228 | F: +617 3252 4769 | E: | ABN 34 009 704 901

Page 1 of 1


APPENDIX C
Results for
1. Species Identification
2. Chemical Analysis for the presence of approved preservatives.

NOTE:
The product assessed in this report is identified as “Sheet 4”.


Queensland the Smart State

DPI&F
Timber identification certificate no. 025
Attention Matthew Bird
Engineered Wood Products Association of Australasia
3 Dunlop Street NEWSTEAD Q 4006

EWPAA

label

ID register

Description

Results

Sheet 1

80
81
82
83
84
85
86
87
88
89-97

Top
Core
Back
Top
Core
Back
Face
Core
Back

Face/back
Core

Shorea spp., red meranti group
Paraserianthes falcataria, white albizzia
Shorea spp., yellow meranti
Lagerstroemia spp., tabek
Paraserianthes falcataria, white albizzia
Shorea spp., yellow meranti
Canarium spp., canarium
Shorea spp., yellow meranti
Shorea spp., yellow meranti
Hardwood; the face and back veneers are too thin for identification
The 9 core plies are Populus spp., poplar

Sheet 2

Sheet 3

Sheet 4

Gary Hopewell MSc
Senior Technician
DPI&F Horticulture and Forestry Sciences
5 February 2008