Technical Standards for Cast Stone

In the United States, the technical standards and guidelines for cast stone are primarily established by the Cast Stone Institute (CSI) and the American Society for Testing and Materials (ASTM). These organizations provide specifications and testing methods to ensure the quality and performance of cast stone products.

At Marcstone our cast stone is routinely tested to ensure that it exceeds CSI and ASTM standards. At a minimum our stone exhibits a compressive strength above 6,500 PSI and an absorption score less than 6%, and our test results consistently improve on these baseline specifications.  

Here are some of the key technical standards related to cast stone:

Cast Stone Institute (CSI) Standards: The CSI publishes a set of standards and guidelines for the manufacturing, testing, and installation of cast stone. These standards cover various aspects, including materials, mix design, fabrication, curing, quality control, and installation.

ASTM C1364 – Standard Specification for Architectural Cast Stone: This ASTM standard provides the minimum requirements for the physical properties, performance characteristics, and testing procedures of architectural cast stone. It covers aspects such as compressive strength, water absorption, freeze-thaw durability, and dimensional tolerances.

ASTM C1194 – Standard Test Method for Compressive Strength of Architectural Cast Stone: This ASTM test method specifies the procedures for determining the compressive strength of architectural cast stone. It outlines the testing equipment, specimen preparation, and testing procedure to assess the strength properties of cast stone.


ASTM C1195 – Absorption

ASTM C1528 – Standard Guide for Selection of Dimension Stone: This ASTM guide provides information on the selection of dimension stone, which includes cast stone. It offers guidance on factors such as stone properties, aesthetics, durability, installation, and maintenance.

It’s important to consult the latest versions of these standards, as they may be updated or revised over time. Additionally, local building codes and project specifications may include additional requirements for cast stone products, so it’s essential to consider those as well. When sourcing cast stone products, it is advisable to work with manufacturers or suppliers who adhere to these industry standards to ensure the quality and performance of the cast stone elements in your project.

The technical specifications for cast stone can vary depending on the specific manufacturer and project requirements. However, here are some general guidelines and considerations:

Raw Materials: Cast stone is typically made from a mixture of crushed natural stone (such as limestone, granite, or marble), fine aggregates (sand or other fillers), cementitious materials (cement or a combination of cement and lime), and water. The specific proportions of these materials may vary based on the desired strength, color, and texture of the cast stone.

Manufacturing Process: The manufacturing process for cast stone involves mixing the raw materials to form a homogeneous mixture. This mixture is then poured into molds, where it is compacted and cured to harden. Various techniques can be used to achieve the desired appearance, including the use of pigments, surface treatments, and texturing.

Compressive Strength: Cast stone is designed to have sufficient compressive strength to withstand the loads it will experience in its intended application. The minimum compressive strength requirement can vary, but it is typically in the range of 5,000 to 8,000 pounds per square inch (psi).

Density: The density of cast stone can range from 120 to 160 pounds per cubic foot (pcf), depending on the specific mix design. The density affects the weight of the cast stone elements and can influence factors such as installation, transportation, and structural considerations.

Absorption: Cast stone should have low water absorption to minimize the effects of moisture, freeze-thaw cycles, and staining. The maximum water absorption for cast stone is typically specified as a percentage of its weight, often ranging from 4% to 6%.

Color and Texture: Cast stone can be manufactured in a wide range of colors and textures to match the desired aesthetic. Pigments can be added during the mixing process to achieve the desired color, while various texturing techniques can be employed to mimic the appearance of natural stone.

It’s important to note that these specifications are general guidelines, and specific project requirements should be determined in consultation with the manufacturer or supplier of the cast stone. Additionally, local building codes and industry standards may provide additional guidance and requirements for the use of cast stone in construction projects.