CeraTex® Ceramic Fiber R-value

In some applications of CeraTex® products people may want to use ceramic fiber “R-value” to calculate what size is needed.

R-value is related to the following factors:

  • Thermal conductivity (k) of the material,
  • Thickness,
  • Tightness of the material (how much it is compressed)
  • Working Temperature

As so many variables affect the R-value, manufacturers normally only give customers thermal conductivity value (provided in data sheet) instead of R-value. If all the factors are known, R-value can be calculated from the thermal conductivity:


T: thickness in inches, k: thermal conductivity in BTU/sqft F/inch

14 Comments on “CeraTex® Ceramic Fiber R-value

  1. I am building a fiber-insulated ceramic kiln and need a roll of ceramic fiber blanket 1″ x 24″ x 50 ft. 8-pound density. What is the cost including shipping to Nashville TN 37013?
    Thank you
    Charles Hooper

  2. So what would be the R-value for CeraTex® 3170 at 1/4 inch at 130ºF?

    I can see Working Temperature listed as 0.05 at 500ºF but dont see any lower figures.

    • CeraTex paper is meant for high temp heat insulation applications. If the working temp is only 130ºF, you really don’t need this insulation. The working temperature is the temperature of the hot side. When you convert to R value, you need to use the thermal conductivity in BTU unit.

  3. I see this product used in van and bus conversions as part/all of the insulation system. Is this product appropriate for this application and will it provide insulation, radiant heat reflection to a level that is worth using this product. Do you recommend cera tex for this application.

    • Our CeraTex sales for bus/van conversions have been growing and these customers are satisfied with the product. CeraTex ceramic fiber paper has been a popular insulation choice for these customers due to its durability and its thickness (thinness). CeraTex seems to be an attractive option for customers who need to insulate an area where space is tight.

      Many bus/van conversions will use some sort of reflective material (similar to a car’s windshield shade) to address radiant heat. CeraTex is not a reflective material, but it is an excellent insulator.

      We certainly recommend this product for insulation, especially when the application area has a limited amount of space. Please let us know if you have any more questions.

      • I got some 1/8′ thick ceratex fiber paper for my bus conversion. When I follow the formula to find the R value I got a decnal number below 1. I guess my math is off. What is the R value of 1/8″ thick ceratex paper please?

        • Hi Roman,

          I apologize for not having a manufacturer’s R-value readily available for this product.

          Assuming you calculated R value = material thickness (in.) / thermal conductivity (imperial units), what value did you use for thermal conductivity in your calculation?

    • I’ve used it with great success in my bus conversion. Not only does it stop the dreaded thermal bridging, but also is good at sound deadening.

      • Thanks for sharing your experience with CeraTex. Really like what you did with the bathroom in the GMC 4905 bus conversion!

  4. A few questions were posted above about R value and Thermal conductivity but I don’t see the answer..
    What is T (or R with thickness specified) for MinSeal Ceramic fiber (this page is titled ceramic-fiber-r-value after all!).
    You can give me the T (Thermal conductivity or R (if you specify thickness. I would appreciate a clearly stated number on either one or both. Thanks.

    • Ceramic fiber blanket is used for high temperature applications. It is not necessary to use it for home insulation.