What is the minimum bearing for a stone lintel on a wall?

The bearing shall not be less than its thickness, with an absolute minimum of 10 cm, as per Clause 4.3.

How should a stone lintel be oriented during placement?

The stone should be placed on its edge, so that the natural bedding planes are vertical and at right angles to the direction of the span (Clause 5.3).

What is the required compressive strength for a sandstone lintel?

A minimum of 35 N/mm² when tested according to IS 1121 (Part 1), as per Table 1.

IS 9394

: 1979

stone lintels

CurrentSpecializedSpecificationBIMStructural Engineering · Stones

Download PDF BIS Portal Google

This standard specifies the requirements for materials, dimensions, finish, and physical properties for stone lintels made from natural stones like sandstone, limestone, and granite. It provides criteria for workmanship and sets minimum physical requirements like compressive strength and water absorption to ensure durability and performance.

stone lintels

Quick Reference Values

Minimum thickness of lintel7.5 cm

Minimum bearing length10 cm (or thickness of lintel, whichever is more)

Minimum compressive strength for Sandstone35 N/mm²

Minimum modulus of rupture for Sandstone3.5 N/mm²

Maximum water absorption for Sandstone (by weight)5%

Dimensional tolerance in length± 5 mm

Dimensional tolerance in width/thickness± 2 mm

Practical Notes

Crucially, the natural bedding plane of the stone must be placed vertically and perpendicular to the span to maximize its load-bearing capacity, as specified in Clause 5.3.

Stone lintels are best suited for relatively small spans. For larger openings, consider composite (e.g., stone-faced RCC) or alternative structural lintels.

Ensure the minimum bearing of the lintel on the supporting masonry is provided to prevent local crushing or shear failure at the supports.