Plywood Buying Guide: Grades, Glue & Core Species

Start with the core, not the price

Plywood is an odd number of veneer layers glued with the grain alternating at 90°. That cross-lamination is what gives the panel its dimensional stability. What changes between products is the species inside, the adhesive between the plies, and the quality of the outer faces.

Two quotations for "18 mm plywood" can differ by 60 % in price and behave completely differently on site — one may be albasia core with E2 urea glue, the other birch core with WBP phenolic. Neither is wrong; they are different products for different jobs. The table below is the fastest way to see where a quotation sits.

Core species comparison

A higher density usually means better screw-holding and impact resistance, at the cost of weight and freight. On a container priced by cubic metre, the density difference between albasia and birch is roughly an extra 20 tonnes per 40HQ — a real cost, not a rounding error.

Glue types: E1, E2, MR and WBP

There are two separate things being described here, and offers often conflate them.

• Formaldehyde emission class — E1 or E2, tested to EN 717-1. This is a health and compliance parameter for interior use, not a water-resistance rating.
• Water resistance — urea (interior), MR melamine-urea (moisture resistant), WBP phenol-formaldehyde (boil proof).

So "E1 plywood" tells you nothing about whether it survives rain. A panel can be E1 and WBP, or E1 and interior-only. When a specification matters, write both: "E1 emission, WBP bonding".

Face grades explained

Grades are written face/back, best letter first. B is a clean, sanded face with small tight patches permitted. BB allows larger patches and some colour variation. C and D are utility faces with knots, discolouration or minor splits. A B/BB panel has one good side; BB/BB has two acceptable sides; C/D is packaging grade.

Buying a better grade than the application needs is one of the most common ways importers overspend. If the panel is going to be laminated or painted, BB/BB is usually enough. Grade only matters where the face stays visible.

Thickness, weight and container loading

A 1220 × 2440 mm panel in 18 mm is 0.0536 m³. Multiply by density to get the weight of a single sheet: about 28 kg in poplar, 37 kg in birch. A 40HQ takes roughly 28 m³ — around 520 sheets of 18 mm — and a 20GP about 20 m³.

Choosing by application

A short RFQ checklist

Send these seven lines and any mill can quote accurately in one pass: face and back species, core species, panel size and thickness, glue type (emission class and water resistance), grade, quantity in m³, and destination port. Anything missing becomes an assumption — and assumptions are where the price difference hides.