R-Values for Natural Stone

It is also common to consider the heat transfer in heated pavement systems where the thermal conductivity of the stone affects the system’s ability to melt snow/ice. The chart below provides the measured thermal conductivity (k-value) and thermal resistance (R-value) of natural stone veneers.

RValue for Natural Stone Veneer

This chart provides the measured thermal conductivity (k-value) and thermal resistance (R-value) of natural stone veneers

Stone Type

K-Value (Terminal Conductivity) (W / MK)

R-Value Equivalent (R) (HR ⋅ ft² ⋅ °F / BTU)

Granite (High Value)

1.73

0.083

Granite (Low Value)

3.98

0.038

Granite (Barre)

2.79

0.052

Limestone (High Value)

1.26

0.114

Limestone (Low Value)

1.33

0.108

Linestone (Salem)

2.15

0.067

Marble (High Value)

2.07

0.070

Marble (Low Value)

2.94

0.049

Marble (Halston)

2.80

0.051

Sandstone (High Value)

1.83

0.079

Sandstone (Low Value - Berea)

2.90

0.050

Quartzite (Sioux)

5.38

0.027

This chart contains general guidelines. Quarry Mill is not responsible for any use or misuse that causes damage of any kind, including loss of rights, materials, and personal injury alleged to be caused directly or indirectly by the information contained in this document

The center column of the table provides the thermal conductivity values for natural stone veneers. The k-value represents the rate at which heat transfers through a solid material. (For example, a material with a k-value of 1.00 indicates that 1 square meter of the material, with a thickness of 1 meter, will transfer heat at a rate of 1 watt for every degree Kelvin of temperature difference between its opposite sides).

A higher k-value means the material is more conductive, while a lower k-value indicates it is more insulating. The right column lists the R-value equivalent (R) for the stone at a thickness of 1 inch, measured in hours per square foot per degrees Fahrenheit per British thermal unit. The high value reflects the highest test result from a range of samples, and the low value represents the lowest test result. This method is the standard for measuring the insulating properties of materials.

Sources:

Holman, J.P. Heat Transfer. 7th ed., New York: McGraw-Hill, 1900. and Introduction to Heat Transfer. 2nd ed. New York: John Wiley & Sons, Inc., 1990.

This document contains general guidelines. Quarry Mill is not responsible for any use or misuse that causes damage of any kind, including loss of rights, materials, and personal injury alleged to be caused directly or indirectly by the information contained in this document.