Timber Panelled And Glazed Shutters, Part 2: Windows and Ventilator Shutters
1994 Edition

Permitted materials for window and ventilator shutters include timber species classified as per IS 12896:1990, ensuring rails and stiles are of the same species, while solid wood panels can vary in species but should be single-piece. Laminated veneer lumber compliant with IS 14616:1999 is allowed for rails and stiles. Panels may be constructed from timber, plywood, blockboard, wire gauze, or glass. This combination ensures durability, uniformity, and conformity with quality standards.

The standard modular dimensions for timber window and ventilator shutters are based on a 100 mm module, accommodating frame thickness and a 5 mm clearance all around. For timber window shutters, sizes include designations like 6 WS 12 (500 mm width x 1100 mm height), 10 WT 12 (460 mm x 1100 mm), and others as per Table 3. Ventilator shutter sizes such as 6 V 6 (500 mm x 500 mm) are provided in Table 4. These sizes facilitate compatibility with standard openings and streamline installation.

IS 1003 Part 2 classifies timber into First and Second Grades based on allowable defects. First Grade timber permits minimal cross-grain (max slope 1:15), limited sound/live knots (up to 15 mm in stiles/rails, 20 mm in panels), and prohibits pitch pockets. Second Grade allows slightly more defects, including knots up to 20 mm in stiles and 4 knots per square meter on panels, with pitch pockets permitted except on exposed edges if properly filled. Dead or loose knots must be plugged, and knots must not be present where hinges or locks are fixed. These grading rules ensure strength and aesthetic quality.

For robust shutter construction, the code recommends using one-piece timber stiles and rails from the same species, with solid wood panels preferably in a single piece. Preservation treatments per IS 401:1982 are required, especially for imported species which may need PCP solvent treatment. Mortise and tenon or dowelled joints, bonded with animal glue (IS 852:1994) or polyvinyl acetate adhesives, are preferred to ensure sturdy, long-lasting connections. Proper assembly and fixture, as detailed in Annex C, prevent warping and maintain flatness.

The slamming test verifies shutter impact resistance by lifting the free edge to a 30° angle at the hinged side and allowing it to drop freely onto the rail by its own weight, repeated 50 times at 4.5 drops per minute. No visible damage is permitted after testing. This test excludes glazed and wire gauzed shutters and is conducted on every 1,000 units produced or after design modifications. Sampling and acceptance follow criteria outlined in the standard to ensure consistent durability and operational integrity.