Plywood

Ridgeons stock, as you would expect, a wide range of panel products including Plywood, OSB, MDF, Chipboard as well as some more specialist Boards. Whilst there are many different types of plywood available, some suitable for external use and others only suitable for dry internal use, they all are... Read More

Ridgeons stock, as you would expect, a wide range of panel products including Plywood, OSB, MDF, Chipboard as well as some more specialist Boards. Whilst there are many different types of plywood available, some suitable for external use and others only suitable for dry internal use, they all are constructed the same, in that the board is manufactured from thin layers of veneers, bonded together.

Glued/Bond and Timber Veneers
Traditionally within the trade people referred to WBP when specifying plywood and some still do today. However, this term no longer applies to plywoods that are available, even though sometimes you can still find it advertised.

The change from WBP came about because of the introduction of new European Regulations that cover the glue line, (or bond quality), in respect to its moisture resistance, (EN314-2: 1993), and also the durability of the timber species used for each individual layer, or veneers. This includes both the Internal and the External ‘Face’ veneers under (EN636: 2012).

The Regulations are further divided into three parts. Each reflects the performance levels of each component. These levels need to match for the Plywood sheets to work in that chosen situation. If they do not match then it will only be suitable for the lowest achieved level, (see over for table showing examples).

Bonding/Glue
EN314-2: Class 1: Dry conditions. Interior applications with no risk of wetting. (Replacing MR – Moisture Resistant)
EN314-2: Class 2: Humid conditions. Protected exterior conditions (e.g. behind cladding or under roof coverings).
(Replacing Type 1)
EN314-2: Class 3: Exterior conditions. Unprotected exterior conditions over sustained periods. (Replacing WBP)
Wood Species
EN636: Class 1: Dry conditions. Interior applications with no risk of wetting.
EN636: Class 2: Humid conditions. Protected exterior conditions (e.g. behind cladding or under roof coverings).
EN636: Class 3: Exterior conditions. Unprotected exterior conditions over sustained periods.

Structural
When using Plywood for wall, floor and roof applications it will generally need to be suitable for structural use. To ensure that the Plywood selected is suitable it must have a CE2+ mark on it. This is proof that the panel has been correctly tested and complies.

One thing to be aware of is that the lower the number the better it is for use in structural situations, for example CE4 graded plywood is not suitable for structural uses.

Sheathing / Shuttering
The term ‘Sheathing’ generally refers to wall sheathing. This usually means that the plywood is being used for timber frame panel construction and as such will need to have a structural performance (i.e. CE2+ marked); this is because it will be used to provide racking resistance during the build. However, if the plywood is going to be used for the internal non load-bearing partition walls, it might not be used in the same way and therefore will not necessarily need to be structural.

More often the term ‘Sheathing’ is used to mean a cheap softwood plywood.

The term ‘Shuttering’ generally means that it is being used for concrete formwork. In this situation the main criteria for the plywood is for it to be good one side, producing a clean/smooth concrete surface. There are other options that have a MDO (Medium Density Overlay) or a Phenolic Film face allowing for these boards to be re-used.

Again the term shuttering can be confused to mean a cheap softwood Plywood.
In both of these cases it shows how essential it is to establish the end use application, to avoid any confusion.

Marine Plywood
There are two commercial types of Marine Plywood:

Imported Commercial Quality (stocked in Ridgeons and complies to EN636: Class 3 and manufactured to BS 1088-2003), which can be used for typical building applications e.g. Deep fascia, bargeboard, soffit, shop fronts, etc. and for use in boat interiors only {but not boat hulls}.

Lloyds Approval BS 1088-2003 Certified Marine Plywood, which is suitable for boat hull construction. Some of the Lloyds approved plywoods have a ten or twenty year guarantee for weather and water-resistance.

Best practice
We recommend that any Plywood sheet used in a situation where moisture may be present, sealed on all four edges with a PVA Glue wash or similar to prevent ingress of moisture which may well result in edge splits and delamination. It is also advisable to do the same with the face sides.

From the information we have provided, it should be apparent that some types of plywoods lend themselves to only very particular applications, whilst others can perform in a multitude of situations. However, there may also be a cost consideration to be aware of. It is with this in mind that we urge both the sales-person and the customer to discuss the end use of the product. Selecting the right product for the intended end use may allow cost savings through the selection of the appropriate product, in addition to avoiding costly ‘call-backs’ and possible remedial work and replacements.