APA is cautioning the marketplace to beware of imported panels that in many cases fail to meet North American standards. APA recently tested samples of nontrademarked imported concrete form panels in which the average glue bond performance of the sample did not meet the minimum standard of US Product Standard PS 1. Test results also indicated that the samples had an average load capacity of approximately 40% below the level of APA PS 1 Plyform plywood and had formaldehyde emissions levels up to 500 times higher than those of domestic production.
In December 2006 and January 2007, APA tested Asian overlaid plywood panels at the APA Research Center in Tacoma, Wash. The purpose of the testing was to benchmark the performance of nontrademarked Asian plywood products relative to the performance required for North American APA-trademarked plywood (Plyform).
APA tested six sets of 11-, 12- and 13-ply 18.3 mm (23/32 inch) Asian plywood panels from five retail sources throughout the United States. The plywood was evaluated for mechanical properties, glue bond performance, and formaldehyde emissions. Comparative data for North American plywood was compiled from US Product Standard PS 1 requirements and APA's testing experience. To see a summary of comparative results, .
These results indicate that substitution of offshore plywood for North American plywood may lead to inferior structural and bond durability performance with a higher level of formaldehyde emission. Substandard panels often give themselves away during installation. Panels that flex excessively or break under low loads may be manufactured from species with inferior strength or with improper adhesive bonds.
The average glue bond performance of the nontrademarked Asian plywood tested by APA did not meet the minimum performance standard of PS 1, Construction and Industrial Plywood, which requires a minimum of 85% wood failure as an indicator that the panels will meet the long-term glue bond performance expectations of concrete forming plywood in harsh jobsite environments. The higher the percentage of wood failure, the better the glue bond performance.
Policing the threat from substandard products is largely up to the professionals within the industry—dealers, code officials, builders, specifiers, designers, engineers, and certification agencies all play a vital role in keeping substandard product off the market. Look for the
Grading agencies in North America have clearly defined stamps. The typical stamp will have the following information:
- Certification agency trademark
- Panel grade (STURD-I-FLOOR, RATED SHEATHING, RATED SIDING, or plywood grade [A-C, C-D])
- Span rating and thickness (e.g. a span rating of 32/16 means that the panel can be used for a maximum span of 32 inches on a roof and 16 inches on a floor)
- Exposure classification (Exposure 1 panels are suitable for wetting and drying under normal construction conditions; Exterior panels are designed for long-term exposure to weather)
- Mill number
- Product and/or Performance standard (PS 1-07, PS 2-04, PRP-108)
If you have concerns as to the validity of the mark, contact the APA Helpdesk at 253-620-7400. A photo of any product labeling may help us determine the source and course of action.
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