What is Plywood? Definition, Structure, Types & Buying Guide
Introduction: Plywood in Thailand’s Climate
In Thailand’s hot and humid climate, plywood quality makes the difference between a project that lasts and one that fails. Poor quality plywood can warp, delaminate, or grow mold within weeks, while the right grade can remain stable and reusable for years.
What is Plywood?
1. The Core Definition
Plywood is an engineered wood product made by gluing together multiple thin layers of wood veneer, each layer’s grain direction rotated relative to the adjacent one. This cross-grained structure increases strength and stability.
2. Why is it Called “Plywood”?
The word “ply” means “layer.” Plywood = layered wood. For example:
- 3-ply = three veneer layers
- 5-ply = five veneer layers
- 12-ply = structural or marine grade boards
3. Key Components of Plywood
Veneer: Rubberwood, eucalyptus, poplar, or pine (rubberwood is common in Thailand).
Adhesive: Determines moisture resistance:
- MR Glue: Indoor use only, not for Thai humidity.
- WBP Glue: Weather & Boil Proof, ideal for construction plywood in Thailand.
Structure & Manufacturing of Plywood
2.1 Cross-Laminated Structure
The alternating grain pattern improves dimensional stability, reduces warping, and enhances strength-to-weight ratio.
2.2 Manufacturing Process
- Log preparation & debarking
- Veneer peeling with rotary lathe
- Drying to 6–12% moisture
- Gluing & lay-up
- Hot pressing at 120–150°C
- Trimming & sanding
- Surface treatment (film faced / decorative)
2.4 Plywood Sizes & Thickness (Thailand Standard)
| Thickness | Applications |
|---|---|
| 3–6mm | Decoration, backing |
| 9–15mm | Furniture, flooring base |
| 18–25mm | Construction formwork, heavy furniture |
Key Properties & Advantages
- Strength & Durability: 18mm film faced plywood supports multiple cycles of concrete pouring.
- Dimensional Stability: Stays reliable during monsoon season.
- Versatility: Furniture, interiors, construction, and packaging.
- Cost-Effectiveness: Higher upfront cost but reusable up to 10–12 times.
- Sustainability: Low-emission (E0/E1) and FSC-certified sources available.
Section 4: Common Types of Plywood
4.1 By Species
- Birch plywood – premium furniture
- Pine plywood – lightweight
- Rubberwood plywood – affordable & local
4.2 By Grade / Application
- Marine Plywood – WBP glue, highly water-resistant
- Structural Plywood – load bearing
- Decorative Plywood – veneered or laminated
4.3 By Finish
- Sanded plywood – smooth finish
- Film faced plywood – construction use
- Melamine faced plywood – cabinets & interiors
Applications of Plywood in Thailand
- Furniture: wardrobes, desks, cabinets
- Construction: concrete formwork, scaffolding
- Flooring: underlayment
- Packaging: crates for exports
FAQ
Q: What is the difference between plywood and MDF?
A: Plywood is stronger and water-resistant, MDF is cheaper but weaker in humidity.
Q: What is Marine Plywood?
A: Plywood bonded with WBP phenolic glue, resistant to water.
Q: What is the standard plywood size in Thailand?
A: 1220 x 2440mm (4×8 feet).
Case Study – Bangkok High-Rise Projects
Switching from MR plywood to 18mm WBP film faced plywood increased reuse cycles from 5–6 to 12–14, reducing formwork costs by 35%.
Conclusion
Plywood is versatile, durable, and cost-effective. For Thailand’s humid climate:
- ✅ Choose WBP film faced plywood for construction
- ✅ Birch or melamine plywood for furniture
- ✅ Rubberwood or pine plywood for packaging
