Are the dimensions in this code for dressed or sawn timber?

The standard dimensions apply to sawn timber. Finished or dressed timber will be smaller than these nominal sizes.

What is the allowable length tolerance for structural timber?

The code allows a length tolerance of +50 mm and -0 mm, meaning it can be slightly longer but not shorter than specified.

Does this standard specify the grading of timber?

No, this standard is strictly for dimensions and tolerances. Grading and strength parameters are covered under IS 3629 and IS 883.

IS 1362

: 1968

Structural Timber - Dimensions

CurrentSpecializedSpecificationBIMStructural Engineering · Timber and Wood

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This standard specifies the preferred dimensions, cross-sections, lengths, and allowable tolerances for sawn timber used in structural applications such as beams, columns, and trusses.

Specifies standard dimensions for various structural timber elements used in building and construction.

Quick Reference Values

Tolerance on dimensions less than 100 mm+3 mm, -2 mm

Tolerance on dimensions 100 mm and above+6 mm, -3 mm

Tolerance on length+50 mm, -0 mm

Standard length increments0.5 m

Practical Notes

Dimensions specified are for sawn timber; appropriate allowances must be made by the designer if the timber is to be planed or dressed.

Engineers should verify the local commercial availability of specific standard sizes and lengths prior to finalizing the design to minimize wastage and cost.

Tolerances assume the timber is at an equilibrium moisture content; green timber may experience shrinkage.