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Richmortar Masonry Cement

Stone Mix Masonry Cements

Type S Gray & Buff
Clinchfield, Georgia

Product Description

StoneMix Masonry Cement is produced to meet the criteria of ASTM C91 “Standard Specification for Masonry Cements” for Type S (Table 1).

StoneMix Masonry Cement consists of a mixture of portland cement, limestone, and chemical admixtures to provide plasticizing properties and other enhanced performance attributes. These components are proportioned at the cement plant under controlled conditions to assure product consistency.

Basic Use: StoneMix Masonry Cement is used to produce a Type S mortar for the installation of natural and manufactured stone masonry, as defined in ASTM C270 “Standard Specification for Mortar for Unit Masonry.”

StoneMix Masonry Cement when mixed with the recommended volumes of sand (ASTM C144) will produce a mortar that will comply with the requirements of ASTM C270 for both the Proportion Specification (Table 2) and the Property Specification (Table 3).

Size: StoneMix Masonry Cement is available in one cubic foot sacks containing a plastic moisture barrier and in bulk via pressurized bulk containers.

Installation More

Mixing: Machine mixing should be used whenever possible. First, add most of the water and half of the sand. Next, add the masonry cement and the rest of the sand. After one minute of continuous mixing, slowly add the rest of the water. Mixing should continue for at least three minutes. Mixing up to five minutes improves mortar qualities.

No admixtures should be used without written approval. StoneMix Masonry Cements have an additive containing a water-repellent component which is interground with the cement during manufacture. No other additives are necessary, unless specified.

Water: All water should be clean and free from organic material and deleterious amounts of dissolved acids, alkalis and salts.

Retempering: To minimize retempering, mortar should not be mixed more than 15 minutes prior to use. Retempering will not adversely affect mortar quality if only evaporated water is replaced. Colored mortar should not be retempered.

Tooling of Joints: Tooling of mortar joints increases the density, durability and water tightness of the mortar surface. The moisture content of the mortar when tooled will affect the color; the drier the mortar, the darker its final color.

Specifications More

Table 1. ASTM C91 Masonry Cement

Physical Requirements of Masonry Cements
Masonry Cement Type Compressive Strength Min., psi (MPa) Water Retention Minimum % Air Maximum %
N 900 (6.2) 70 21
S 2100 (14.5) 70 19
M 2900 (20.0) 70 19

Table 2. Proportion Specification (Parts by Volume)

Mortar Type Masonry Cement Type N Masonry Cement Type S Masonry Cement Type M Masonry Sand
N 1 - - 2 ¼ - 3
S - 1 - 2 ¼ - 3
M - - 1 2 ¼ - 3

Table 3. Property Specification

Under the Property Specification, the cement-to-sand proportions are to be in the range of 1:2 ¼ to 1:3 ½, and should meet the requirements outlined in Table 3.

Mortar Type Compressive Strength Min., psi (MPa) Water Retention Minimum % Air Maximum %
N 750 (5.2) 75 20
S 1800 (12.4) 75 18
M 2500 (17.2) 75 18

No changes should be made in the field to the laboratory established proportions for mortar that has been tested and accepted under the property specification, except for the quantity of mixing water.

Materials with different physical characteristics than those used in the laboratory should also not be used in the field without testing for compliance with the property specifications.

Mortar Coverage Estimation More

Mortar Coverage Estimation Sheet

Type S
Unit Pieces per One Bag of Masonry
8x8x16 CMU 33 - 35
12x8x16 CMU 25 - 28

Type N
Unit Pieces per One Bag of Masonry
Modular Brick 125 - 133
Queen Brick 85 - 90
Utility Brick 77 - 81

*All estimates are approximate.

Building Materials Calculator More
Stone Mix coverage calculator
Area (sq. ft.) to cover:
Thin/Thick wall:
Number of bags needed:
Mortar bags needed for block count
Block count
Mortar Bags Required:
(add approx. 5% to the total for waste)
Block required
Length (ft)
Height (ft)
Total Block Required:
(add approx. 5% to the total for waste)
Sand amount needed for block count
Block count
Sand (tons) Required:
(add ½ yard to the total amount you will need)
Block fill
Block count
Block Size
6" 8" 12"
Cubic Yard Required:
(add ½ yard to the total amount you will need)

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