APAwood – Europe

The leading resource for information about engineered wood products for the UK and Europe

About APA

Products & Trademarks

Official Guidelines

Green Topics


Contact us

Exterior or Exposure 1?

Choosing Exterior or Exposure 1 Plywood Panels

The three key requirements for US product standard PS2-18 are dimensional stability, bond performance and structural adequacy. To comply, the mills need to consider veneer thickness, strength of species used to peel the veneers and the number of veneers/layers – and a combination of all three when determining the final layup.  

Choosing  Exposure 1 or Exterior?

Exterior and Exposure 1 panels use 100% waterproof adhesive and conform to Bond Class 3 in European standard EN 314-2 on bond quality. Selecting the right product depends on moisture exposure.

Exterior: for use with long term or permanent exposure to the weather with no ground contact or for use in areas of high moisture such as bathrooms or kitchens. Exterior plywood is normally a smoother veneer and uses higher grades (refer to PS1-19 veneer grading rules) with smaller open characteristics permitted. 

Exposure 1: intended to resist the temporary effects of moisture due to construction. These panels are not suitable for long term or permanent exposure to the weather.

Compositional factors may also affect the bond performance in the area around some larger open characteristics of the inner veneers, so how the panel will be used has to be taken into account when specifying the product. Also see specifying your product for use in the UK and EU.