Medium strength mortar suitable for exposed masonry above grade is classified as which type?

The classification of medium strength mortar suitable for exposed masonry above grade falls under Type N mortar. This type of mortar is well-regarded for its versatility and is specifically designed for general use in above-grade masonry, including brick and block work. Type N mortar has a balanced ratio of cement to lime, offering adequate strength and flexibility, which makes it ideal for use in applications where moderate compressive strength is required, such as in non-load-bearing walls and exterior veneers.

Type O, on the other hand, is a low strength mortar not suitable for most structural applications. Type M is a high-strength mortar, often used in heavy-duty load-bearing applications. Type S is a medium-strength mortar but is specifically designed for below-grade applications like foundations and retaining walls due to its superior bonding and weather resistance properties. Hence, Type N is the most appropriate classification for medium strength mortar meant for masonry that is exposed and situated above grade.