Mortar Mixing for Clay Brick — The Right Ratios for Ghana

Why mortar mix matters

Mortar should be slightly weaker than the brick. When the wall moves — and every wall moves a little, with temperature, humidity, and settlement — the mortar should absorb the movement, not the brick.

If mortar is stronger than the brick (too much cement), the brick cracks instead. Cement-rich mortar is the most common cause of brick wall failures on Ghanaian sites.

The right mixes

For GBQS-certified clay brick in typical Ghanaian conditions:

• •Standard structural: 1 cement : 1 lime : 6 sand (by volume)
• •Lime-free alternative: 1 cement : 5 sand + plasticiser
• •Below-DPC / foundation masonry: 1 cement : 3 sand (stronger to resist ground moisture)
• •Decorative / pointing: 1 cement : 1 lime : 4 sand for crisper joint finishes

Water and workability

Add water gradually until the mortar holds shape on a trowel but spreads cleanly. Too wet and it sags out of joints; too dry and it doesn't bond.

Never re-temper mortar that has started to set by adding more water — its structural strength is already compromised. Mix small batches you can use within 90 minutes.

In Ghana's climate

In peak sun, shade the mortar and the bricks while you work. Hose bricks briefly before laying. If mortar is drying in the bed before you place the next brick, you're working too slowly or in too much sun — move the work.