ledged braced and battened timber door shutters
1992 Edition

The standard recommends timber species classified under IS 12896:1990, ensuring uniformity by using the same species for ledges, braces, and battens (with battens as solid wood requiring a single species). Preference is given to timber sourced from industrial or social forestry plantations or reclaimed wood rather than natural forests. Annex A lists suitable imported species such as Dark Red Meranti (Shorea spp.), Merbau (Intsia Palemanica), Afromosia (Afromosia angolensis), and Afara (Terminalia Superba), among others. Using these species ensures durability, consistency, and environmentally responsible sourcing.

Timber is categorized into First and Second Grades based on permissible defects. First Grade timber allows minimal imperfections, such as cross-grain not exceeding 1 in 15, limited small sound knots, no pitch pockets, minimal sapwood, and no wormholes. Second Grade timber permits more defects within defined limits, including slightly steeper cross-grain, larger and more knots, allowed pitch pockets away from exposed edges (which must be properly filled), more extensive sapwood, and limited wormholes that are plugged with matching timber. Checks with maximum width 0.25 mm and depth 10 mm are allowed in both grades, with the same species used for ledges, braces, and battens to maintain structural integrity.

Door shutters are designed based on a modular system using 100 mm increments for width and height. Designations like '8 DS 21' correspond to an 800 mm wide single shutter with approximately 2100 mm height. Standard widths include 700, 800, 900, and 1100 mm (for double-leaf shutters combined width). Heights are typically 1905 or 2005 mm, with finished floor level heights slightly higher. Component dimensions have specified widths and thickness tolerances, for example, top and bottom ledges are 150 ±1.5 mm wide and 25 ±1.5 mm thick, with battens between 140 and 160 mm wide uniformly. Overall shutter size tolerance is ±3 mm, allowing for consistent manufacturing and installation.

Type testing must be conducted in accordance with IS 13034:1990 whenever there is a design change. Tests include the slamming test, shock resistance test, edge loading test, and resistance to buckling test. At least three samples are tested for these evaluations. The tests confirm the structural and mechanical performance of the door shutters under various impact and load conditions. Manufacturers are required to provide test certificates on demand, ensuring the product meets the defined standards.

Door shutters should be hammer-marked on the visible edge of a ledge or batten with details including the manufacturer's identity, whether the shutter is modular or non-modular, and its designation or actual size. Modular shutters use a format indicating width and height in 100 mm modules along with shutter type symbols (D for door, S for single shutter, T for double leaf). For example, '8 DS 21' indicates a single shutter 800 mm wide by 2100 mm high. This marking ensures traceability, size accuracy, and compliance with modular coordination, facilitating quality control and identification.