For designers working with structural plywood a number of different plywood stress grade standards may apply. The plywood standard AS/NZS2269.0:2008 and the timber design standard AS1720.1:2010 list different grade stresses for the same plywood grades. In addition plywood standard 2269.0:2008 lists three techniques for determining plywood stress grades, two of which were not in existence when the original plywood strength properties were developed.

A recent project, comissioned by Forest and Wood Products Australia (FWPA) related the strength and stiffness properties of current softwood/hardwood plywood resources from both Australian and New Zealand against the existing plywood stress grades.

The research showed AS1720.1:2010 matched the plywood stress grades best, and as a result, Australian designers of plywood structures should use the characteristic values from that standard. Researchers believe plywood stresses in AS/NZS2269.0:2008 should be amended to reflect those in AS1720.1:2010 or those in AS1720.1:2010. FWPA has initiated a project to undertake this work. The planned revision of NZS3603:1993 should also adopt the plywood stress grades from AS1720.1:2010.

The project confirmed that plywood grade stresses in AS 1720.1:2010 align well with the F8, F11 & F14 plywood resource from both Australia and New Zealand.

Read the full report here at www.fwpa.com.au

Labels: Treated Plywood, Plywood,