How we supply it: AAC blocks are arranged through a partner block supplier who quotes, supplies and bills them and pays us a referral commission. If you would rather build with solid blocks or bricks, those come from our own stock yards at factory-direct wholesale prices, and either way we deliver the M-Sand and P-Sand for mortar and plaster.
In one line: An AAC block is a precast walling unit of cement, lime, fly ash or sand and a little aluminium powder, foamed into countless small air cells and cured under steam pressure in an autoclave.
What makes AAC light
An AAC block is a precast walling unit of cement, lime, fly ash or sand and a little aluminium powder, foamed into countless small air cells and cured under steam pressure in an autoclave. The air cells make it roughly a third the weight of brick masonry for the same volume.
IS 2185 (Part 3) covers these blocks and groups them into density classes. Common house-site blocks sit around 550–650 kg/m³ when dry (typical).
Sizes and where each goes
| Thickness | Trade name | Blocks per m³ | Typical use |
|---|---|---|---|
| 100 mm | 4 inch | 83 | Bathroom and wardrobe partitions |
| 150 mm | 6 inch | 56 | Internal room walls |
| 200 mm | 8 inch | 42 | External infill walls |
| 230 mm | 9 inch | 36 | External walls matching 9-inch brick lines |
AAC vs red brick vs solid concrete block
| Point | AAC block | Red clay brick | Solid concrete block |
|---|---|---|---|
| Wall weight | Lightest | Heavy | Heaviest |
| Joints per m² of wall | About 8 | About 50 | About 12 |
| Jointing | 2–3 mm thin-joint adhesive | 10–12 mm cement mortar | 10–12 mm cement mortar |
| Heat through the wall | Lowest | Moderate | Highest |
| Fixing heavy shelves | Needs AAC anchors | Ordinary plugs | Ordinary plugs |
| Who supplies it | Partner, arranged | Our stock yards | Our stock yards |
Blocks per wall: the arithmetic
Typical estimate: from the 600 × 200 mm face (0.12 m² per block). Thin joints are ignored; add 3–5% for cutting and breakage.
Plaster over AAC is thinner than over brick, so the P-Sand quantity drops too. Ask your mason for the thickness he plans before ordering sand.
- 100 sq ft of wall (9.29 m²): about 77 blocks, 80–81 with wastage, at any thickness
- One room of 12 × 10 ft, 10 ft high, minus a door and window (about 40 sq ft): 440 sq ft net, about 340 blocks before wastage
- By volume, one 600 × 200 × 200 mm block replaces about 12 modular bricks laid in mortar
Checks when the blocks arrive
- Measure five blocks: length, height and thickness should match within a few millimetres, with sharp edges.
- Weigh one block: a dry 600 × 200 × 200 mm block at 600 kg/m³ is about 14.4 kg; a much heavier one is wet or of a denser class.
- Count broken and chipped blocks per pallet and note them on the delivery slip.
- Ask for the lot's test certificate showing density class and compressive strength to IS 2185 (Part 3).
- Check the jointing adhesive bags are the type meant for AAC, with a packing date.
Handling and stacking
- Unload by hand or forklift; tipping from a lorry breaks corners.
- Keep pallets on level, dry ground and cover them in the rains; soaked blocks shrink as they dry and crack the plaster.
- Lay blocks dry with only a light surface wetting, never saturated.
- Store adhesive bags like cement: raised and covered.
AAC mistakes masons make
- Laying in thick cement mortar like bricks; the joints shrink differently and crack.
- No mesh at the junction of AAC walls with RCC columns and beams before plastering.
- Thick plaster on AAC without a bonding coat.
- Hanging kitchen cabinets on ordinary plastic plugs.
- Leaving out lintels and the RCC band where the drawing shows them.