Type N Mortar Mix

Type N mortar is useful for exterior and above-grade walls which are uncovered to harsh weather and high heat. Type N mortar mix contains a medium compressive strength and it is made of 1 part Portland cement, 1 part lime, and 6 parts sand. It is treated as a general-purpose mix, suitable for above grade, exterior, and interior load-bearing installations. It is also very effective for soft stone masonry. Type N is commonly utilized by the homeowners and is ideal for general application.

It usually attains 28-day strength in the range of 750 pounds per square inch (psi).


Type O Mortar Mix

Type O mortar mix contains comparatively low compressive strength, at only about 350 psi. It is mainly applied for interior, above-grade, non-load–bearing walls. Type O is a good substitute of Type N for some interior applications, but its exterior application is restricted because of its low structural strength. It is not suitable for the areas prone to high winds. However, type O mortar mix is useful for repointing and same type of repair work on subsisting structures, owing to its uniformity and smooth application.