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IS 1659:2004 is the Indian Standard (BIS) for blockboards - specification. This standard specifies the requirements, grading, and methods of test for blockboards used in general woodwork, furniture, partitions, and paneling. It categorizes blockboards into two primary grades based on the adhesive used: Boiling Water Resistant (BWR) and Moisture Resistant (MR).
Specifies the requirements for blockboards, including their types, grades, dimensions, physical properties, and testing methods.
Covers performance requirements for wood-based panels for use in dry, humid, and exterior conditions, which is analogous to IS 1659's MR and BWP grades. Blockboard is considered a type of plywood construction in this context.
ANSI/HPVA HP-1-2020ANSI / HPVA
HighCurrent
American National Standard for Hardwood and Decorative Plywood
Directly covers 'lumber core plywood', the American term for blockboard, within its scope, specifying grades, core construction, adhesives, and performance tests.
ISO 12465:2017ISO
MediumCurrent
Plywood — Specifications
Provides international specifications for plywood. While blockboard is a specific construction, many of the performance principles (bonding, strength) and testing frameworks are relevant.
JAS 1751:2014MAFF (Japan)
MediumCurrent
Japanese Agricultural Standard for Plywood
Covers various types of plywood, including those with a lumber core (ランバーコア合板). It specifies performance by type (e.g., Type 1 for exterior) and formaldehyde emission levels.
Key Differences
≠IS 1659 uses a grade system based on adhesive type (BWP for Phenol Formaldehyde, MR for Urea Formaldehyde), whereas EN 636 classifies based on end-use conditions (dry, humid, exterior) which are linked to separate bonding classes defined in EN 314-2.
≠The Indian standard is highly prescriptive about core construction, specifying a maximum core strip width of 30 mm. International standards are often more performance-oriented or have slightly different dimensional constraints.
≠IS 1659 lists specific Indian timber species suitable for the core and veneers, while international standards like EN 636 and ANSI/HPVA HP-1 are generally species-agnostic, focusing on the final performance properties of the panel.
≠Test methods for water resistance differ significantly. IS 1659 (BWP grade) requires a 72-hour continuous boiling water test with a visual delamination check, while EN 314-2 Class 3 involves a cyclical boil-dry-boil procedure followed by a quantitative shear strength test.
Key Similarities
≈The fundamental definition of blockboard (a core of solid timber strips laid edge-to-edge and sandwiched between veneers) is consistent across all standards.
≈All standards classify products based on their suitability for different moisture environments to ensure fitness-for-purpose (e.g., Interior/MR vs. Exterior/BWP).
≈Core mechanical properties such as bending strength (Modulus of Rupture) and stiffness (Modulus of Elasticity) are specified and tested in all standards to ensure structural integrity.
≈All standards mandate requirements for bonding quality or glue line adhesion, which is a critical performance characteristic for any laminated wood product.
≈Dimensional and visual quality criteria, including tolerances for thickness, length/width, and limits on surface defects, are a common feature of all specifications.
Parameter Comparison
Parameter
IS Value
International
Source
Moisture Content
5% to 15%
6% to 14% (at time of delivery/testing)
ANSI/HPVA HP-1-2020
Max. Core Strip Width
30 mm
Often not specified, performance-based. Older EN 12775 specified max 33mm.
EN 12775 (historical)
Thickness Tolerance (Sanded Panel)
±5% (for thickness < 20mm)
±(0.2 + 0.03t) mm, where 't' is thickness. (e.g., ±0.74mm for an 18mm board)
EN 315
Adhesion Test (Exterior Grade)
No delamination after 72 hours boiling.
Pass multi-cycle boil-dry test and meet minimum shear strength (e.g., >1.0 N/mm²).
EN 314-2 Class 3
Min. Bending Strength (MOR) along grain
40 N/mm² (for thickness ≥ 19mm)
Varies by grade; often specified as a lower characteristic value for structural design (e.g., 15-25 N/mm² 5th percentile).
EN 12369-2 (for EN 636)
Min. Stiffness (MOE) along grain
3500 N/mm² (for thickness ≥ 19mm)
Varies by grade; characteristic values for structural use often range from 3500-7000 N/mm² (5th percentile).
EN 12369-2 (for EN 636)
⚠ Verify details from original standards before use
Key Values6
Quick Reference Values
Moisture content5% to 15%
Standard thicknesses12, 15, 19, 25, 30, 35, 40, 50 mm
Length and width tolerance+6 mm, -0 mm
Thickness tolerance±5%
Edge straightness tolerance0.2 percent
Squareness tolerance0.2 percent
Tables & Referenced Sections
Key Tables
Table 1 - Requirements for Physical and Mechanical Properties
What are the standard thicknesses available for blockboards?+
Standard thicknesses are 12, 15, 19, 25, 30, 35, 40, and 50 mm according to Clause 9.1.
What is the difference between BWR and MR grade blockboards?+
BWR (Boiling Water Resistant) uses synthetic resin adhesives suited for exposure to water/moisture, while MR (Moisture Resistant) uses urea-formaldehyde adhesives intended for dry indoor applications.
What is the acceptable dimensional tolerance for length and width?+
The tolerance for length and width is +6 mm and -0 mm.
What is the permissible moisture content for a standard blockboard?+
The moisture content should be between 5% and 15% at the time of testing.