BS 1088 is the British Standard for marine plywood that applies to plywood produced with untreated tropical hardwood veneers that have a set level of resistance to fungus and water. The plies are bonded with Weather Boil Proof (WBP) glue. Normally the highest standards of WBP glue is Dynea resin from Norway.
Although BS1088 is a British Standard, the marine plywood does not have to be manufactured in Britain as long as the final products comply with the standard.
The standard is associated with Lloyd’s Register since it performs testing of products to this standard.
WBP Glue Line
BS 1088 plywood must use an adhesive, which has been proven to be highly resistant to weather, micro-organisms, cold and boiling water, steam and dry heat.
The face veneers must be free of knots other than “sound pin” knots, of which there shall be no more than six(6) in ANY area of one square foot. There can be no more than an AVERAGE of two such knots per square foot over the entire surface. The veneers must be reasonably free from irregular grain. The use of edge joints is limited, and end joints are not allowed.
Core veneers have the same basic requirements as face veneers, except that small splits are allowed, and there is no limit on the number of pin knots or edge joints. However, end joints are not allowed.
Limits of Manufacturing Defects
Defective bonds, pleats and overlaps, and gaps in faces are not permitted. Occasional gaps may be repaired using veneer inserts bonded with the proper resin.
BS 1088 plywood must have a moisture content 6% – 14% when it leaves the mill.
4 mm +.02/-0.6 ; 6 mm +.04/-0.65 ; 9 mm +.06/-0.75 ; 12 mm +.09/-0.82
15 mm +.1/-0.9 ; 18 mm +.12/-0.98 ; 22 mm +.16/-1.08 ; 25 mm +1.8/-1.16
Face Veneer thickness
For any three-ply construction, which applies to 3 and 4 mm material, each face veneer shall be not thinner than 1/8 of the total thickness of veneers assembled dry.
Multi-Ply Construction– This applies to boards thicker than 4.8 mm (3/16″)
Each face veneer shall be a minimum of 1.3 mm and not thicker than 3.8 mm.
Each core veneer shall be no thicker than 4.8 mm