Mortar is classified into four basic types. Type M mortar is a high strength mortar and recommended for use below the grade where it will be in contact with the earth.
Type S is usually specified for exterior use above the grade and especially where there are lateral forces on the wall. Type S is used in both reinforced and unreinforced masonry. It develops a high tensile bond and is often used where mortar is needed between facing and backing.
Type N mortar is for general use above ground where high compressive or lateral strengths are
not needed. It is a medium strength mortar. It is usually used for parapet walls, chimneys and exterior walls with severe exposure.
Type O mortar is a low strength mortar recommended for load bearing walls only where the compression does not exceed 100 pounds per square inch and where the masonry is not subjected to freezing and thawing. Type O is recommended for non-load bearing walls and for general interior use.
Many other types of specialty mortars are available. There is refractory mortar for laying fire
brick: Gypsum mortar and tuck pointing mortar for laying gypsum block and tuck pointing respectively; dirt resistant mortar that resists staining; grout used in reinforced walls, bond beams or inside the masonry cells themselves; latex mortar; epoxy mortar; ready-mix mortars; and more.
Bon Tool Co. has made a serious effort to provide exact and current information, but does not guarantee the accuracy of the data. Bon Tool Co. cannot assume responsibility for the application of information nor guarantee results.
