Type M: This is the strongest mortar available to the average person. It is very often used in stonework because the chemical composition is similar to stone and the adhesion properties for stone are superior. Since its compressive strength is great, it is an outstanding choice for foundations, below grade brickwork, weight bearing walls and driveways. Although it has excellent adhesion for stone, it often is a poor choice for certain types of brick. Although this mixture is very strong, it is considered very difficult to use.
Type N: This mixture is of medium strength, and is ideal for chimneys, garden or landscape retaining walls. It is good for above grade and can withstand the elements, including severe cold and heat. It is considered easy to use. This type of mortar takes approximately one month to cure, at which time it reaches its maximum strength.
Type O: This mortar has the lowest compressive strength and normally is best used indoors. When it is applied outside it should be used only above grade and in non-load bearing situations. It is very easy to use.
Type S: This mortar has relatively high compressive strength, yet is somewhat easy to work with. It is often used below grade including for the use of foundations.
The above explanation is only a very basic overview of the varying types of mortar. When applied to the different types of bricks, one mortar might work very well while another won’t. This is usually due to the water absorption rates of diverse types of brick. An experienced brick repair artisan such as Casey Thebolt of CTV3 Enterprises should be consulted if there are any questions about which type of mortar to use. To learn more about CTV3 Enterprises, visit: http://ctv3enterprises.com/ or call 248-906-2883.