Mortar in construction of buildings

•         Mortar is the material used in bedding, jointing and pointing bricks and blocks in masonry walling. The use of mortar in brickwork or masonry is to bind together the bricks or stones, to afford them a soft resting-place, which prevents their inequalities from bearing upon one another.

•          Thus to cause an equal distribution of pressure over the beds.

•          It also fills up the spaces between the bricks or stones and renders the wall weather-tight. The quality of mortar depends upon the description of materials used in its manufacture, their treatment, proportions, and method of mixing. 

Mortar consists of:

• Sand.

• Ordinary Portland cement.

• Water.

• Plasticizer.

• Retarders.

• Accelerator.

• Pigments or colouring agents.

• Hydrated lime.

Requirements of a Mortar Mix

The main requirement of a good mortar mix is workability.

Bricklayers require a mortar mix which is described as ‘fatty’. This means it hangs on the trowel without being sticky, it spreads easily and it does not stiffen too quickly or too slowly.

The mortar should meet other requirements to ensure that it retains its strength and durability during the life of the brickwork or block work.

These requirements include:

• Adequate compressive strength.

• Adequate bond strength between mortar and bricks.

• Durability – resistance to frost and chemical attack.

• Joints sealed against wind-driven rain.

• An attractive appearance.

The ability of the mortar to meet these requirements will depend upon:

• The materials specified for the mix.

• The workmanship of the bricklayer.

• The protection of the materials and brickwork against adverse weather.