what is plywood? – Plywood is several panels comprising of at least 3 layers of veneered wood called plies which are bonded together with adhesives. With each ply produced at right angles to the adjacent layer to improve strength and reduce the possibilities of shrinkage along with making it more structurally stable. The outer layers of ply are referred to as face & back are graded based on quality of the face and reverse, the layer in between face & back is more commonly know as the core. Plywood glue is graded for internal & external use.
Classifications & Grades of Plywood
A/BB grade – Face veneers almost free from all defects. Reverse veneers allowing jointed veneers, large knots, plugs, & discolouration with some slight colour variation.
B grade – Both face & back veneers have a few small knots with slight discolouration.
B/BB grade – Face veneers only have a few small knots & slight discolouration. With back veneers allowing jointed veneers, large knots, plugs, & discolouration with some slight colour variation.
BB grade – Both face & back veneers allow jointed veneers, large knots, plugs, discolouration & slight colour variation.
What is Q Mark
Q Mark set up by Trada in the U.K. is a strict third party evaluation to ensure the manufacturing mill carry out all necessary procedures & checks to ensure the ply meets in accordance with E.N. 13986:2004. Participating factories are monitored and continuously on a month by month basis, & therefore Bm Trada Q Mark is the new industry standard for plywood & sheet materials in the U.K.
What is Certification of Wood Based Panel Products
In the context of wood based panel products certification is the process of a third party with the authority to attest that performance claims for the products are true.
What is CE Mark
A CE Mark is specified by the CPR, that a manufacturer places on the product or its packaging to signify that the product is fir for its intended purpose, use, or specified range of uses (subject to proper design maintenance & building practice) & thus enables the construction to satisfy the relevant essential requirements of the CPR. It is a passport to the European market, not a quality mark.
What is WBP
WBP or weather & boil proof is still an endearing term that is still used by a large majority of the timber trade to describe exterior plywood. Officially WBP was a term used in BS6566-4:1985 to determine grade of glue used.
This standard is now obsolete as of 1998 & is now superseded by BSEN-314-2:1993
Class 3 bond, the exterior is now largely comparable with what the timber trade refers to as WBP, for exterior use only.
What is BSEN314-2:1993
Plywoods is produced with glue bonds which range from those suitable for interior use to those which will withstand full exposure for long periods. BSEN314-2:1993 plywood bonding quality requirements define three classes of plywood on basis of test requirements that plywood bonding must meet.
Class 1 Dry Conditions – For interior applications with no risk of wetting.
Class 2 Humid Conditions – Protects external and damp internal conditions.
Class 3 Exterior – Exposure to all weathers over substantial periods.
contact us for more details on 01273 426588 or alternatively email us at firstname.lastname@example.org.