What is mortar and what is its function?

One of the most important materials that are essential for the success of many building projects nowadays is widely known as “mortar.”  Mortars are workable pastes that are specially made for construction use.

Most people can buy pre-mixed mortar in home improvement shops, and they can also mix it themselves. When the right amounts of ingredients are mixed, mortar can be made to be stronger or more durable to perform well. For example, a building that is several floors high must be constructed with quality materials. If mortar is necessary, the contractor will make sure that the mortar type and mix they use should hold for a long time.

To know more about the mortar used for masonry, its function, and how it is made, read on below. Understanding mortar should not only be for those people working in the construction industry. As a homeowner or building owner, knowing more about the materials that build your property and make it a safer place is absolutely worth your time, especially if you are planning to have one constructed in the future.

What mortar means

Mortar in itself is a confusing topic for those who have never seen one. Often, it can be called by others as “concrete” or “cement”, as they are usually seen in construction sites. Although it is common for cement and concrete to be mistaken as mortar, they cannot be called the same.




By definition, mortar is simply a paste made with water, cement, and aggregates to form the mixture. Just like the glue that we have used in many art projects since kindergarten, mortar is primarily used as a bonding agent that is used to bind objects together.

In construction, mortars bind masonry units (such as brick and concrete) when they are placed in between the gaps and spaces during the placement of the blocks. Back in the earlier years, mortars were commonly used in building necessary structures such as wells and houses.

What does mortar look like?

The regular or common type of mortar we usually see comes in a medium shade of gray. Due to differences in the mixture, the paste can be light gray or darker gray once it dries. In the present, mortar can come in different shades of white to maximize aesthetic appeal.

Because mortar is a paste that uses water as an ingredient, it is wet and sticky to touch. However, the consistency of the mortar will depend on the other additives that were mixed, as they can be made to be more workable, thicker, or thinner, for it to work with the project and material it will be used in.

What is mortar used for?

Mortar does a lot of things besides gluing things together. In construction, mortar has been a great help in working with brick, masonry, and other CMUs. (Concrete Masonry Units)

  1. It joins masonry construction materials together.

As was mentioned earlier, mortar is compared to glue because it works as an adhesive that binds two or more materials in one piece. The most common masonry units that mortar is compatible with are brick, marble, glass, and concrete.

  1. It helps in closing and filling gaps, joints, and holes.

When some parts of the walls are cracked and damaged, filling the space with mortar helps with closing the holes and smoothing out the surface.

Applying mortar to the joints in your walls makes it be more durable and makes it more resistant to weather-related problems in the future.

  1. It adds support to your structure.

When mortar is used to level the layers of your building, the result will be stronger and more durable. This also helps in distributing the weight it has to carry equally, which makes your building last longer.

What are the ingredients of mortar?

In the past, the ingredients that are required to make mortar are just mud and clay. This simple mixture has been tested and improved in the present to be able to stand against moisture and extreme weather. By adding more ingredients that are possible due to technological advancements, mortar can even be bought in sacks that are conveniently available in home improvement stores.

To make mortar, the ingredients are cement, sand, aggregates, and water. Adding other ingredients such as lime is optional. Depending on where it will be used, one can opt to buying dry mixed mortar or by having their contractor make it on site.

The purpose of cement in mortar is that it is an ingredient that makes the mortar bind. When in paste form, the mixture of water and cement will eventually harden when it dries, which makes the masonry units stick together.

The most common type that is used with mortar is the Portland Cement, as it is proven to be more durable and great for heavy structures.

The purpose of sand in mortar is that it is an ingredient that makes the mortar retain its structure and appearance in its dried form.

Sand does this by reducing the shrinkage during the setting and drying process. Using sand on mixtures can also cut the cost as it is significantly cheaper than other materials.

The purpose of aggregates in mortar is that it is an ingredient that makes the mortar mix stronger, cheaper, and more rigid. Sand is one example of an aggregate, but stone and gravel are also included in the category.

The reason why aggregates are often used is that they are cost-effective. When used as fillers, they are able to cover more areas, though using more aggregates than recommended lessens the strength of the mortar mixture.

The purpose of hydrated lime in mortar is that it is an ingredient that makes the mortar bind, just like how cement is used. Lime helps with the curing process of mortar, which can make it more workable compared to cement that dries quickly.

Nowadays, lime can be viewed as an optional ingredient by some people, as cement is more accessible and better with compression strength. Adding just the right amount of lime to your mix can make your project less susceptible to water damage.