Plywood & OSB Panels vs. Glulam Timber Beams
Comparing 2 standards across 14 specifications. 14 key differences identified.
Structural wood panels including softwood plywood and Oriented Strand Board (OSB) are standardized under Voluntary Product Standards DOC PS 1 and PS 2. Sized in standard 4×8 ft (1219×2438 mm) sheets, panels are classified by 'Performance Category' thickness with a -1/32" decimal reduction, where a nominal 1/2" panel measures 15/32" (0.469" / 11.9 mm).
Structural Glued Laminated Timber (Glulam) under ANSI A190.1 is an engineered heavy timber beam manufactured by face-bonding individual 2x softwood dimensional lumber laminations with structural adhesives. Featuring standardized widths of 3-1/8", 5-1/8", and 6-3/4" and depths in 1.5-inch increments, Glulam beams support spans exceeding 100 feet.
Specification Comparison Table
14 Parameters| Parameter / Spec | ||
|---|---|---|
|
Governing Standards
|
DOC PS 1 (Plywood) / DOC PS 2 (OSB) / APA PR-N108 | ANSI A190.1 / ASTM D3737 / APA EWS S475 |
|
Standard Sheet Dimensions
|
4 × 8 feet (48.0 × 96.0 inches / 1219 × 2438 mm) | — |
|
Metric Sheet Dimensions
|
1220 × 2440 mm (European & Asian standard) | — |
|
1/4" Category Thickness
|
15/64 inch (0.234" / 5.95 mm) | Underlayment | — |
|
3/8" Category Thickness
|
11/32 inch (0.344" / 8.73 mm) | Wall sheathing | — |
|
1/2" Category Thickness
|
15/32 inch (0.469" / 11.91 mm) | Standard roof sheathing | — |
|
5/8" Category Thickness
|
19/32 inch (0.594" / 15.08 mm) | Heavy-duty roof / subfloor | — |
|
3/4" Category Thickness
|
23/32 inch (0.719" / 18.26 mm) | Standard subfloor (T&G) | — |
|
Western Species Net Widths
|
— | 3-1/8" (79 mm) | 5-1/8" (130 mm) | 6-3/4" (171 mm) | 8-3/4" (222 mm) |
|
Southern Pine Net Widths
|
— | 3-1/2" (89 mm) | 5-1/2" (140 mm) | 7-1/4" (184 mm) | 9-1/4" (235 mm) |
|
Standard Lamination Thickness
|
— | 1.50 inches (38 mm) per lamination |
|
Standard Depths
|
— | Multiples of 1.5" (e.g., 6", 7.5", 9", 10.5", 12", 13.5", 15", 16.5", 18", up to 30+") |
|
Standard Stress Class
|
— | 24F-V4 (2,400 PSI bending stress / 1.8 × 10⁶ PSI MOE) |
|
Appearance Classifications
|
— | Framing (hidden), Industrial, Architectural, Premium (exposed) |