What is the difference between EN 314 and EN 636?
EN 314 is the glue-line durability test. It pre-treats a plywood sample (cold water soak, boil cycle, etc.) and then stresses the glue lines in shear. EN 636 is the panel's overall service-class spec, combining bond, veneer durability and construction. A Class 3 bond under EN 314 is required for an EN 636-3 panel, but a panel can pass EN 314 Class 3 and still fail the broader EN 636-3 spec if other elements are out of tolerance.
Is an E1 plywood panel automatically TSCA Title VI compliant?
No. E1 is the European formaldehyde emission class under EN 13986 with a ceiling of 0.124 mg/m³ steady-state. TSCA Title VI and CARB Phase 2 in the US set tighter ceilings on certain product groups (0.05 ppm hardwood plywood). A panel needs both marks if it ships into both markets, and a TSCA Third-Party Certifier (TPC) certificate is the document US customs checks for.
What is the difference between 'marine grade' and BS 1088 plywood?
BS 1088:2018 is the British Standard for marine plywood and requires mahogany or okoumé face veneers, full hardwood through-construction, no voids, WBP phenolic glue, and a Lloyd's Register stamp confirming third-party verification. 'Marine grade' as a retail term is unregulated — a sheet labelled marine grade without a BS 1088 reference and Lloyd's stamp meets no specific standard. For surveyor-accepted boat work, only the Lloyd's stamp counts.
How do I verify a CE mark on plywood is legitimate?
Three checks. First, request the Declaration of Performance (DoP) — every CE-marked construction product must have one, and the manufacturer is obliged to provide it. Second, cross-reference the four-digit notified body number in the CE block against the EU's NANDO register; a body not in NANDO does not issue valid marks. Third, verify the mill code against the manufacturer's published list. Missing any of these three signals is a strong counterfeit flag.
What does the span rating like 48/24 on an APA stamp mean?
The two numbers are the maximum centre-to-centre support spacings in inches. The first number (48) is the maximum rafter spacing when the panel is used as roof sheathing. The second number (24) is the maximum joist spacing when the panel is used as floor sheathing. Both ratings assume the panel is oriented with its long dimension across the supports.
Why doesn't a panel stamp list the reuse cycle count for formwork plywood?
Reuse cycle counts are service-life expectations under disciplined site handling, not stamped guarantees. A film-faced panel rated 'up to 20 reuse cycles' will deliver close to that with proper edge sealing, clean stripping, careful handling and a quality release agent. Same panel abused on site might give 5 cycles. Because the count depends on site behaviour, no certification body stamps it. Manufacturers publish it as application guidance, not as a tested limit.
