What is the acceptable moisture content for general-purpose plywood?

Between 5% and 15% at any time of the year.

What type of adhesive is required for MR grade plywood?

Urea formaldehyde synthetic resin adhesive conforming to IS 848.

What type of adhesive is required for BWR grade plywood?

Phenol formaldehyde synthetic resin adhesive conforming to IS 848.

IS 303

: 1989

Plywood for General Purposes - Specification

CurrentFrequently UsedSpecificationBIMArchitectural · Timber and Wood

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This standard specifies the requirements for general-purpose plywood used in interior and semi-exterior applications. It defines the manufacturing processes, materials, and testing methods for Moisture Resistant (MR) and Boiling Water Resistant (BWR) grades.

Lays down the requirements for plywood intended for general applications, covering types, dimensions, quality, and testing.

Quick Reference Values

permissible moisture content5% to 15%

standard thickness range3 mm to 25 mm

thickness tolerance less than 6mm± 10%

thickness tolerance greater than 6mm± 5%

BWR water resistance test requirementBoiling water for 8 hours

MR water resistance test requirementWater at 60±2°C for 3 hours

Practical Notes

Do not confuse BWR (Boiling Water Resistant) under IS 303 with BWP (Boiling Water Proof) marine plywood under IS 710. BWR is meant for interior/semi-exterior use, whereas BWP is for marine and fully exposed conditions.

General-purpose plywood under IS 303 should not be used for concrete shuttering; use IS 4990 for formwork/shuttering plywood.