AAC is a factory product, which makes it easy to check objectively. Five minutes with a tape and a scale at the gate catches most problems.
The Seven Checks
| Check | How | Good result |
|---|---|---|
| Size | Measure length, height, thickness of several blocks | Consistent within a few mm |
| Weight | Weigh a few blocks | About 14 kg (8 inch), 11 kg (6 inch), 7 kg (4 inch) dry |
| Edges and corners | Visual | Sharp, few chips |
| Cracks | Visual, tap | None through the block |
| Texture | Look at a cut or broken face | Uniform fine cells, no large voids |
| Moisture | Feel, weight | Dry or slightly damp, not soaked |
| Certificate | Ask the supplier | Density and strength results for the batch |
Why Size and Weight Matter
- Size accuracy is what lets masons use 2–4 mm adhesive joints. Inconsistent blocks force thicker joints, which waste AAC's insulation and invite cracks.
- Weight tells you about density and moisture. Much heavier than expected means the block is wet (it will shrink as it dries in the wall) or denser than specified (less insulation).
Handling and Storage
- Unload by hand or on pallets, never by tipping.
- Stack on level ground, off the soil.
- Cover during rain.
- Count against the invoice per pallet.
What to Reject
- Broken or split blocks.
- Heavily chipped blocks beyond a small allowance.
- Blocks with through-cracks.
- Soaked blocks, unless they can dry before use.
The Short Version
Tape, scale, eyes and a certificate: consistent size, expected weight, clean edges, no cracks, not soaked. Good blocks make good thin joints.
