Marine Plywood -Specification
2010 Edition

IS 710 establishes the criteria for plywood used in engineering and construction applications, emphasizing marine environments. It includes general quality requirements, timber types, finishing standards, and testing protocols. Tender submissions must include three samples of at least 90 mm by 60 mm, representing timber species such as Birch (BIR), Teak (TEA), Rosewood (ROS), among others. Mechanical properties like modulus of elasticity and rupture are specified for both grain directions, alongside preservative retention as per IS 2753 and edge straightness and squareness testing methods.

This section details the requirement for submitting three tender samples, each no smaller than 90 mm by 60 mm, which serve as benchmarks for timber selection, finish, and quality. It lists the acceptable timber species with their botanical names and marking abbreviations. Moisture content limits are governed by IS 287, while test procedures for tensile strength, bending strength, density, and shear strength follow the IS 1734 series. Adhesive content must not exceed 10% by mass. Edge straightness and squareness are verified using specified tools.

This chapter defines the permissible timber species for face veneers, including Birch (BIR), Bonsum (BON), Chaplash (CHP), Gurjan (GUR), Mahogany (MAO), and Teak (TEA), among others, as per Table 1. Core veneers have their own approved species list. Adhesive solid content must remain under 10% by weight. Tender samples are mandated at minimum dimensions of 90 mm by 60 mm. Edge straightness and squareness are measured to ensure compliance within tolerances outlined in Annex B. Cross-references to related Indian Standards are provided.

Materials used must meet tensile strength criteria as specified in IS 1734 Part 9. Adhesives are limited to a maximum solid content of 10% by mass. Approved timber species for face veneers are listed, including Birch, Bonsum, Chaplash, and Teak. Wet bending strength testing involves cycles of boiling and drying, followed by soaking before evaluation, with minimum modulus of elasticity and rupture values defined for both along and across face grain directions.

Finished plywood boards must adhere to dimensional tolerances such as +6 mm length, +3/-0 mm width, and thickness limits depending on nominal size. Edge straightness and squareness should not exceed 2 mm per 1000 mm length. Face veneers must be free from sapwood, and core veneers may include sound knots up to 50 mm, with no dead knots or overlaps permitted. Surface finish must be smooth, with sanding on both sides if requested. Testing methods for edge and squareness follow Annex B procedures.

Standard plywood sizes include 2400x1200 mm, 2100x1200 mm, and others. Length tolerance is +6 mm, width tolerance is +3/-0 mm, and thickness tolerance is ±10% for boards under 6 mm thickness. Edge straightness and squareness must be within 2 mm per 1000 mm. Measurements are taken using straight edges and 500 mm squares as described in Annex B, ensuring dimensional precision for construction and engineering applications.

Plywood must have a reasonably smooth finish, with sanding on both sides if the purchaser demands. Face veneers should have no sapwood, while core veneers can have sound knots no larger than 50 mm. Dead knots, overlaps, and pleats are prohibited. Dimensional tolerances align with those specified in Clause 6.3, with edge straightness and squareness verified per Annex B. These requirements ensure high-quality workmanship and surface integrity.

Each plywood sheet must bear clear and permanent markings, including the manufacturer's name or trademark, manufacturing year, timber species abbreviations, batch number, and ECO-Mark details if applicable. Marking size and location should meet purchaser specifications. The BIS Standard Mark is regulated under the BIS Act 1986, and usage depends on licensing. Timber species abbreviations for marking are provided to maintain traceability and compliance.

Testing involves submission of three tender samples no smaller than 90 mm by 60 mm representing the product quality. Moisture content testing follows IS 287, preservative estimation complies with IS 2753, and plywood strength tests adhere to IS 1734 parts. Edge straightness and squareness are evaluated as per Annex B. Water resistance is assessed through vacuum steam pressure testing or boiling water exposure, with wet bending strength measured to confirm mechanical adequacy.

Manufacturers seeking ECO-Mark certification must obtain environmental clearance from relevant pollution control authorities per Water and Air Acts. Documentation proving compliance must be submitted to BIS. ECO-Mark combines BIS Standard Mark with an environmental logo and is optional. The plywood must fulfill all IS 710 mechanical and preservative criteria alongside environmental standards. Mechanical properties required for ECO-Mark certification are specified with minimum modulus of elasticity and rupture values.

Use of the BIS Standard Mark is governed by the BIS Act 1986 and requires a license. Each plywood board must be marked legibly with manufacturer identity, production year, timber species code, batch number, and ECO-Mark certification if applicable. Tender samples must be submitted to represent the product standard. This system guarantees product traceability, compliance, and quality assurance in line with IS 710 and BIS regulations.

Three tender samples, each at least 90 mm by 60 mm, must be provided with tenders. These samples set the standard for timber species, finish, and quality upon acceptance. The samples should comply with veneer quality, species, and preservative retention specifications. Key associated tables detail minimum mechanical properties and allowable veneer defects, ensuring samples accurately reflect the intended production quality.

IS 710 incorporates multiple Indian Standards crucial for timber and plywood quality control, including IS 287 for moisture content, IS 707 for timber terminology, IS 1734 series for plywood testing, IS 2753 for preservative estimation, IS 7638 for sampling methods, and IS 10013 for wood preservatives. These references provide detailed testing, sampling, and material specifications essential to compliance.

Edge straightness is measured by placing a straight edge equal to the plywood length against the board edge, adjusting for convexity and recording the maximum gap, which must not exceed 2 mm per 1000 mm. Squareness is checked using a 500 mm square, measuring the maximum gap between the square arm and adjacent edge, with the same tolerance. These methods ensure dimensional accuracy and are performed according to IS 7638 sampling procedures.

This method involves cutting six specimens approximately 250 mm by 100 mm with grain direction parallel to length. Specimens undergo three cycles of boiling for 4 hours followed by drying for 16 hours at 65 ± 2°C, or continuous boiling for 72 hours. After cyclic treatment, specimens are soaked for 1 hour at 27 ± 2°C before testing modulus of elasticity and rupture. This accelerated test ensures compliance with durability and strength requirements under harsh marine conditions.