AAC blocks and red bricks compared
| AAC blocks | Red clay bricks | |
|---|---|---|
| What it is | Autoclaved aerated concrete: cement, lime, fly ash or sand and an aerating agent, cured under steam pressure | Clay, moulded or wire-cut and fired in a kiln |
| Indian Standard | IS 2185 Part 3 | IS 1077 |
| Common size | 600 × 200 mm face; 100–200 mm thick | 9 × 4 × 3 inch (about 230 × 110 × 75 mm) |
| Typical density | About 550–700 kg/m³ | About 1,600–1,900 kg/m³ |
| Joints | Thin-bed adhesive or a thin mortar joint; few joints | 10 mm cement mortar; many joints |
| Laying speed | Fast: one block covers the face of 6–12 bricks | Slower |
| Heat | Air cells insulate, so rooms gain heat more slowly | Denser, passes heat more readily |
| Fixings and chases | Needs anchors made for AAC; cuts easily with hand tools | Holds ordinary plugs; chases take longer to cut |
| Weather | Must be plastered or coated outside | Wire-cut bricks can be left exposed |
| Who supplies it | Arranged through local partner suppliers | Our stock: factory-direct from Gummidipoondi SIPCOT |
Verdict: AAC suits upper-floor infill walls in framed buildings where weight and speed matter, if your engineer agrees and your mason has laid it before. Red bricks suit small houses, compound walls, exposed brickwork and sites where masons prefer bricks.
From our team
Notes, photos and examples added by the M&B Chetty team, with the author and the date.
How many bricks equal one AAC block?
Count by wall face, because that is how walls are built. With 10 mm joints a 9 × 4 × 3 inch brick covers about 240 × 85 mm of face, so one square metre takes about 49 bricks in a 4.5-inch wall and 98 in a 9-inch wall.
| AAC block | Replaces, by wall face | AAC blocks per 100 sq ft |
|---|---|---|
| 600 × 200 × 100 mm (4-inch) | ≈ 6 bricks in a 4.5-inch wall | ≈ 76 |
| 600 × 200 × 200 mm (8-inch) | ≈ 12 bricks in a 9-inch wall | ≈ 76 |
Before openings and wastage. AAC sizes vary by maker; confirm the face size on the partner supplier's quote.
Questions to settle before you switch to AAC
- Engineer: lighter walls change the loads on beams; let the structural engineer confirm the design and the block grade.
- Mason: AAC needs thin-bed adhesive or a careful mortar joint and its own cutting tools. Ask whether your mason has laid it before.
- Fixings: list the heavy items (lofts, water heaters, wall-mounted TVs) and buy anchors made for AAC.
- Plaster: plan the plaster or coating for outer walls; AAC is not left exposed.
Who supplies what
- Red clay bricks and fly ash bricks: our stock, factory-direct from Gummidipoondi SIPCOT, delivered from the nearest of our six yards. Red chamber bricks per 1,000, before GST and delivery: ₹10,350 per 1,000 bricks.
- AAC blocks: arranged through local partner suppliers, who pay us a referral commission. Our AAC block rate page shows an indicative Chennai market rate per block; the partner supplier confirms the day's rate when you order.
Stock items: Factory-direct wholesale prices — usually lower than retail dealers; final price negotiable on quantity.