New block makers often blame the machine when blocks come out poorly. In practice, most problems come from the material or the routine around it. Check these common mistakes first.

1. Skipping the soil test

Using whatever soil is nearest can lead to cracked or crumbly blocks. Spend a day on the simple soil tests before you commit to a source.

2. Not sieving the soil

Stones, lumps and roots create weak spots and stop the mix from filling the mould evenly. Sieve the soil and break up all lumps before mixing.

3. Inconsistent cement dosing

Estimating cement “by eye” gives blocks of different strengths in the same wall. Measure with the same container or by weight every time, and record the ratio.

4. Poor mixing

Dry mix until the colour is uniform, then add water gradually. Streaks of unmixed cement or soil mean the batch is not ready.

5. Wrong moisture level

Too wet and blocks slump or stick to the mould. Too dry and they crumble and have rough edges. Use the squeeze-and-drop check described in our cement ratio guide.

6. Machine not stable

A manual press has to be properly mounted so it can transmit the pressing force into the ground rather than rocking. Fix it firmly to a solid base and check the fixings regularly.

7. Uneven filling and pressing

Fill the mould the same way each time and use a consistent, full pressing stroke. Variations show up as blocks with different heights and densities, which makes wall building harder.

8. Letting blocks dry too fast

Sun and wind ruin otherwise good blocks. Follow the routine in our guide to curing stabilised soil blocks.

9. Stacking and using blocks too early

Young blocks are weak. Give them time to gain strength before stacking high or building with them.

10. No quality checks

Keep a simple log: date, soil source, cement ratio, number of blocks and any problems. Test a few blocks from each batch by soaking and by breaking. A written record lets you trace a problem back to its cause.

If you are still struggling with block quality after working through this list, contact our team and describe what you are seeing.

• block making
• quality control
• troubleshooting