When choosing mortar, the impulse may be to purchase the strongest type available. This is often a bad idea: mortar is used to hold brick together but should also be able to absorb impacts allow for a little give, allowing the entire brick structure to stand. Below is a primer on choosing mortar as well as the five most common mix types you will encounter at your local home improvement store.Mortar is bought as a combination of Portland cement and sand. Water is added, creating a chemical reaction that creates a curing process similar to concrete. Each type of mix has specific strengths and weaknesses. A particularly strong mortar may not work well with some brick projects and be difficult to work with. A mix that is easier to work with may sacrifice some strength, but allow the user to create a better project overall.
Type N is of medium strength, which means it is the best choice for projects with bricks that are not load bearing. Garden walls, chimneys, and barbeques are common applications for this mix. Type N is also preferred for soft stone masonry. This is the mortar most often used by home owners. It is easy to work with and is appropriate for most brick projects that the typical home owner would attempt.
Type S is known for its strength and is used outdoors. Patios, foundations, and retaining walls all use Type S, which is known for its ability to absorb most impacts. Type S is still an easy product to work with, but homeowners should have some experience working with brick before beginning any type of project that requires this product.
----The strongest mix that you will find in a home improvement store, Type M is typically used only with stone.Type M is preferred with stone because the strength of the mortar typically mimics that of the stone being used. It is also used in situations where being able to bear heavy loads are important, such as retaining walls.