Masonry can refer to either the building of a structure from masonry units (brick, concrete block, natural stone among other materials) or the masonry units themselves. We do not distribute the units but we do sell a variety of mortars or grouts for use with masonry units. Different types of mortars are suitable for various masonry units and it is important that the correct mortar is chosen for end-use requirements. These mortars differ in their compressive strengths, flexibility and bonding properties and are chosen on the basis of specifications, site conditions and any special job requirements.
Type N Mortars
Typically a Type N mortar is used above grade in an exterior or interior wall with non-load bearing purposes. It is generally used for clay brick or soft stone walls. Often you will see the term 1-1-6 in relation to Type N mortars, which refers to the mix design consisting of 1 part Portland cement, 1 part lime and 6 parts sand. It has a relatively low compressive strength that allows the mortar to crack under stress rather than the masonry unit itself cracking as it is much easier to repair the mortar than the masonry units.
Type S Mortars
Type S mortars are for use below grade with typical examples being masonry foundation walls, retaining walls, sewers and manholes and brick pavers. Type S is much stronger than Type N with compressive strengths generally ranging from 12 to 21 MPa (1800 - 3000 psi). The mix design for Type S is 2-1-9, 2 parts Portland cement, 1 part lime and 9 parts sand.
Masonry grouts or core fill grouts are used to reinforce hollow concrete masonry units (CMU’s), commonly referred to as concrete block walls. The grout is poured into the hollow cavities of the block wall during construction. It is a fluid, cementitious, non-shrink material designed to reinforce CMU’s to increase the strength of the wall as well as bonding the adjacent CMU’s to each other and any steel reinforcement that may be used within the wall.
There are also specialty mortars that are used occasionally, Type O, M and rarely Type K. The Type O features low compressive strength at around 2.4 MPa (350 psi), used typically for interior non-load bearing walls, similar in use to Type N. Type O however is primarily used in repointing applications due to it’s nice consistency and easy application for that type of work. Type M is generally used below-grade for heavy applications with natural stone as the compressive strength is similar to the stone at around 17 MPa (2500 psi). The rarely used Type K is designed for use with historical restoration projects and has an extremely low compressive strength as was typical when ancient or historical buildings were built.