What type of mortar would generally be used for non-structural applications?

The use of Type O mortar is suited for non-structural applications primarily due to its lower compressive strength and flexibility compared to other types of mortar. Designed with a maximum compressive strength of around 350 psi, Type O mortar provides adequate bonding for light-duty projects such as interior non-load bearing walls, historical masonry work, and repointing of brick in certain non-structural contexts.

In applications where high strength and durability are not critical, Type O mortar allows for easier tooling and is more forgiving in terms of movement or slight settling of masonry elements. This characteristic makes it a preferred choice for interior or renovation projects where the structural integrity is primarily provided by other systems and the mortar serves mostly for adhesion and weathering protection.

The other mortar types, such as M, N, and S, are formulated with higher compressive strengths and are generally used in structural or load-bearing applications where robustness and durability are necessary.