Manufactured from wood, plywood consists of fine sheets of wood. These veneers resulting from the peeling
of wood logs are then cut, dried, glued and finally superposed in order to obtain a highly resistant material.
Thus, it is easy to recognise plywood among all the panel types on the market. Even if the wooden surface
is often covered, the plywood panel can be distinguished by its laminated structure noticeable on its side edges.
Light and easy to install, plywood offers excellent resistance to creep. Its cross layers gives it a good stability
and high resistance to impacts and weathering.
Completely versatile, it is suitable for the most extreme uses: nautical construction, decoration, building,
Manufactured from logs coming from forests under long–term durable management, plywood is above all a
material which can be recycled. It actively contributes both to the protection of the environment and the
ecological and economic balance of the wood channel.
The mechanical characteristics of plywood panels vary according to their compositions (species used,
lay-out and thickness of the plies). Nevertheless they generally remain very close to those of solid timber
while having the advantage of a greater regularity and a greater stability. This results from the elimination
of important defects during the preparation of the veneers and the dissemination of the residual minor
defects in the panel.
There are thus no standard values for the mechanical properties of plywood. Each manufacturer provides
his own values according to the composition of his products.
2 series of different values can be provided:
• those resulting from controls in the factories on small samples, used for classification as defined in
standard EN 636
• those resulting from tests on semi-size samples (tests according to standards EN 789 and EN 1058) or
derived from the values measured in the Factory Production Control (using standard EN 12369-2).
Only such values are usable for structural design.
EN 314-2 defines the tests to be carried out to check the bonding class of a panel.
These classes correspond to the following conditions of use:
Class 1: dry interior
Class 2: humid interior
Class 3: exterior
Usually, urea-formaldehyde resins are used for class 1, melamine-urea-formaldehyde for class 2,
melamine-urea-formaldehyde or phenol-formaldehyde for class 3.
The adhesives used for the manufacture of plywood contain synthetic resins (aminoplastic or phenoplastic).
These resins are manufactured from formol ( a soluble formaldehyde in water) and contain small quantities
of free formaldehyde, necessary for a good hardening of the adhesive.
Although the hardened adhesive only contains traces of free formaldehyde, very weak quantities of
formaldehyde can be released, particularly during the first weeks following the manufacture of plywood.
According to the reference standard, EN 636, a panel is classified according to formaldehyde release
Class E1: less than 0,1 ppm according to EN 717-1
Class E2 : more than 0,1 ppm according to EN 717-1
All the manufacturers, members of EPF only, put products on the market matching this class.
Plywood is a product in great demand because it offers a large variety of finishings; from the most traditional
to the most sophisticated , you have the choice of all the different types of plywood:
• Raw and natural
• Covered with a decorative veneer
• Moulded into shape
The choice of a plywood for a given use is in general done according to 2 criteria:
- according to its basic characteristics (bonding class, specific properties)
- according to the wood species constituting its faces
All wood species may be used for this type of use.
Panels with a bonding class 1 may only be used in dry conditions.
For humid conditions, a bonding class 2 is necessary.
The reference standard for this type of panel is EN 636 (-1 or –2).
Certain species, due to their insufficient natural resistance against the wood-destroying fungi, may not be
used for the manufacture of plywood for exterior conditions, unless they have undergone an appropriate
It is imperative to use the bonding class 3.
In all cases, the durability of a plywood panel exposed to bad weather can only be assured by respecting
the installation rules and having a suitable finishing.
The reference standard for this type of panel is EN 636 (-3).
Okoumé is a tropical wood species which is harvested in Gabon, in Equatorial Guinea and in Congo.
It is a light wood (density 0,4 to 0,5), pink-red colored and easy to peel.
It is appreciated for the manufacture of plywood because its quality is homogeneous and it provides a
consistency of surface quality giving an excellent finish (varnish, paint). Okoumé-based plywood is easy
to machine and, with an adapted bonding, can be used in external applications.
Maritime pine has been used for the manufacture of plywood since the 1970’s.
The high mechanical characteristics of this species make this type of plywood particularly suitable for
structural applications in building (racking in timber-framed houses, load-bearing floors, I-beams...) but
also for industrial packing and boxes.
Grooved, it is used in the interior covering of walls and its good resistance to fungi enables its use for
A fast-growing species which presents an excellent aptitude for peeling, poplar is very much used for
the manufacture of light packaging (cheese boxes, small crates for fruit and vegetables...).
Particularly light (density from 0,4 to 0,45), white, resistant, poplar plywood is particularly valued in
packaging and furniture.
Spruce plywood is mainly used as construction panel such as concrete formwork and scaffolding
and in the vehicle industry. Spruce is a good panel for general applications where strength, stability
and lightweight properties are needed, such as for floors, lining and roofs.
Spruce plywood is used uncoated (mainly grades II and III) or coated by phenolic films, usually
120 g/m², 170 g/m² and 220 g/m². Spruce plywood is suitable for internal and external sue, depending
on the level of protection required.
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