IS 1344 : 1981Masonry Cement - Specification

IS 1344:1981, as catalogued here, is a specification for masonry cement — a binder engineered for masonry mortars and plasters, not structural concrete. It belongs with the masonry-cement family (IS 3466): deliberately lower strength than OPC but with high workability and water retentivity so mortar bonds and cures against absorbent bricks instead of being sucked dry.

It sits in the masonry stack:

• IS 3466 — masonry cement (the principal masonry-cement specification) · IS 2250 — preparation & use of masonry mortars
• IS 10850 — water-retentivity apparatus (the defining-property test) · IS 269 — OPC (the *concrete* cement, not for mortar) · IS 456 — concrete

A good masonry mortar must be weaker and more workable than the units it joins and must hold its water against thirsty bricks. A masonry-cement specification controls a binder built for exactly that:

• Lower compressive strength than OPC by design — the mortar is the flexible, sacrificial, repointable element; a rigid, over-strong mortar cracks the units and the wall
• High water retentivity (IS 10850) — resists the brick's suction so the cement hydrates instead of drying to a chalky, debonded joint
• Good workability / board life — full, well-filled joints without segregation

The engineering point is the same as for IS 3466: the recurring masonry defects — cracked brickwork, hollow joints, crazed and falling plaster — come from using the wrong, too-strong, low-retention binder (typically neat rich OPC) for mortar. A masonry cement puts the deliberately weak, water-retentive, workable binder in the joint where it belongs. (Specify the current masonry-cement standard for new work and verify the actual product against it.)

Scenario: brick masonry plus internal/external plaster.

Step 1 — pick a masonry binder: masonry cement (IS 1344 / IS 3466) or properly cement–lime-gauged mortar per IS 2250 — *not* a rich neat-OPC mix.

Step 2 — proportion to IS 2250: a mortar grade matched to the masonry duty, deliberately weaker than the units.

Step 3 — exploit water retentivity: the masonry-cement mortar holds water against the bricks (still pre-wet very absorbent bricks) → full, bonded joints, long board life.

Step 4 — cure: moist-cure masonry/plaster — retentivity buys time, it doesn't replace curing.

Result: full, flexible, bonded joints and a plaster that doesn't craze. The endemic cracked-brickwork / falling-plaster complaint is the wrong, too-strong binder — exactly what a masonry-cement spec exists to displace.

1. Using neat rich OPC for mortar/plaster. Too strong, harsh, low water-retention → cracked masonry, hollow joints, crazed plaster.

2. Using masonry cement for structural concrete. It is deliberately low-strength — never for RCC/structural work.

3. Mortar stronger than the units. Reverses the intended sacrificial behaviour; cracks migrate into bricks/blocks.

4. No pre-wetting of absorbent bricks + no curing. Even a water-retentive mortar is overwhelmed by dry bricks and no curing.

5. Citing a withdrawn edition. Specify the current masonry-cement standard and verify the product; treat superseded years with care in specifications.

• IS 3466 — masonry cement (principal specification) · IS 2250 — preparation & use of masonry mortars
• IS 10850 — water-retentivity apparatus (defining-property test)
• IS 269 — OPC (concrete cement — not for mortar) · IS 456 — concrete
• IS 4031 Part 1 — cement physical tests (adapted for masonry cement)

Catalogued here as a masonry-cement specification, IS 1344 carries the same hard-won lesson as IS 3466: masonry failures are overwhelmingly mortar/plaster failures, and most come from the counter-intuitive habit of using the *strongest* binder available in the joint. The right masonry mortar is deliberately weaker, softer and more water-retentive than the units — the sacrificial, repointable element, not the hardest thing in the wall — and masonry cement is engineered to deliver exactly that. Specify a masonry binder (masonry cement or properly gauged cement–lime) per IS 2250, keep the mortar weaker than the units, exploit the water retentivity (still pre-wet thirsty bricks) and cure. For specifications, cite the current masonry-cement standard and verify the actual product, treating older editions with care. Get the binder right and the cracked-brickwork / falling-plaster complaint largely disappears.