In plywood industry, the term WBP stands for Water Boil Proof, a type of glue used to make the most durable plywood. WBP glues can be melamine or phenolic resin. To be considered exterior grade or marine grade, plywood must be produced with WBP glue.
Plywood Basics
Plywood is constructed of three or more thin sheets of wood (called veneers) glued together, with each layer laid with the grain running at right angles to the next layer. Each sheet of plywood consists of an odd number of veneer sheets. The cross-hatching of the wood grain makes plywood stronger than boards and less susceptible to warping.
WBP Plywood – The only plywood recommended for exterior use
Most sources refer to WBP as Water Boil Proof, but this is somewhat incorrect. WBP is actually a standard that was developed in Great Britain and is set down in British Standards Institution standard 1203:1963, which identifies four categories of plywood glue based on durability. WBP is the most durable glue you can find. In descending order of durability, the other glue classes are Boil-Resistant (BR); moisture-resistant(MR); and interior(INT). According to the FAO of the United Nations, properly formulated WBP plywood is the only plywood recommended for exterior use.
China made WBP plywood is used in outdoor such as house building, shelters & covers, roof, container flooring, concrete shuttering etc. It is a structural plywood that has much more strenth than normal ply from manufacturers.
Melamine vs Phenolic Resin
WBP plywood made with ordinary melamine rather than phenolic resin can maintain lamination in boiling water 4-8 hours. High-grade melamine plywood can withstand boiling water for 10-20 hours. WBP plywood using ordinary phenolic resin glue can handle boiling water for one to three days. It should be noted that the length of time plywood can withstand boiling water without delaminating also depends on the plywood quality.
When you want to buy WBP plywood from China, make sure that you know what type of glue is used in the manufacturing process. Phenolic resin is much more expensive than melamine glue. Strength are quite different too.
