Mortar

Q: What are the basic ingredients in masonry mortar?

A: Masonry mortar is composed of one or more cementitious materials, fine mason sand and sufficient water to produce a workable mixture. The cementitious material may be a portland cement/lime mixture or masonry cement. A typical mortar consists of 1 part cementitious material to 2 ¼ - 3 ½ parts sand by volume.

Q: When do you use mortar?

A: Mortar for unit masonry is intended to be used with brick, block and stone construction. The prime function of the mortar is to bond the individual masonry units into a consolidated mass. ASTM C270 is the Standard Specification for Mortar for Unit Masonry, which covers mortars for use in the construction of non-reinforced and reinforced unit masonry structures.

The three most commonly used types of mortars are designed as Type M, Type S, and Type N. Type M has a compressive strength of 2500 psi; Type S 1800 psi and Type N 750 psi . Type M is used only in special applications requiring high strength mortar. Type S is the most versatile and cost effective and can be used both above and below grade. Type N is limited to above grade construction.

Q: What can I use to repair mortar joints?

A: Deteriorated mortar should be chiseled out and replace with either Type N or S mortar. Sakrete Concrete & Mortar Repair can be used for small non structural repairs.

Q: Can Sakrete Glass Block Mortar Mix be used to lay brick?

A: Yes. Sakrete Glass Block Mortar Mix is a Type S Mortar and can be used to lay brick.

Q: What is mortarless block construction?

A: This type of construction allows the dry stacking of block without the use of mortar in the joints. Sakrete Surface Bonding Cement, with its interlocking fibers, can be used as a coating in place of mortar. Both sides of the wall must be coated. Check local regulations before using mortarless block construction.

Q: What is efflorescence and how can you correct it?

A: Portland cement, masonry cement and lime, as well as products containing these ingredients, such as concrete block, contain naturally occurring water-soluble salts. As moisture moves through the masonry, it dissolves and carries the salts to the surface of the masonry.

Once on the surface of the masonry, the water evaporates leaving a whitish deposit of salt on the surface. This natural formation of whitish surface staining is called “efflorescence.” When efflorescence is light, it can be removed with water and a brush. Severe cases will require the use of an acid.

Q: What is stucco?

A: Stucco is the term used to refer to an exterior plaster usually composed of a standard plaster sand, portland cement, and hydrated lime or masonry cement and sand. The same mixtures are also conveniently available as Sakrete Type S Mortar Mixes. Application traditionally consists of one, two or three coats - scratch coat (first), brown coat (second) and finish coat (third or final) or brown and finish in a two-coat application

Q: Can I use mortar mix or sand mix to repair or build a fireplace or BBQ pit?

A: No. Repairs or construction requiring high heat tolerances need a special refractory mortar.