Is it true?

[trish2]

During a woodshop  club meeting, one of the members said he heard that plywood  is now made with only exterior glue.  Thus there is no difference between interior and exterior grade plywood.  Does anyone know for sure whether this is true?  Others said that there are other differences (besides glue) between interior and exterior plywood.

Thanks for any light you can shed on the subject.

[MountainDon]

Another case where a little information can go off in the wrong direction.

The below is copied from a document from the APA.


Exterior panels have a fully waterproof bond and are designed for applications subject to permanent exposure to the weather or to moisture.

Exposure 1 panels have a fully waterproof bond and are designed for applications where long construction delays may be expected prior to providing protection, or where high moisture conditions may be encountered in service. Exposure 1 panels are made with the same exterior adhesives used in Exterior panels. However, because other compositional factors may affect bond performance, only Exterior panels should be used for permanent exposure to the weather.

Exposure 2 panels (identified as Interior type with intermediate glue under PS 1) are intended for protected construction applications where only moderate delays in providing protection from moisture may be expected.

Interior panels or panels which lack further glueline information in their trademarks are manufactured with interior glue and are intended for interior applications only.