Calcium Silicate

8 - calcium silicate


Calcium silicate insulation is composed principally of hydrous calcium silicate that usually contains reinforcing fibres; it is available in moulded and rigid forms.

Flexural and compressive strength is good. Calcium silicate is water absorbent; however it can be dried out without deterioration. The material is non-combustible and used primarily on hot piping and surfaces. Jacketing is field applied.

Historically, common practice was to use calcium silicate for applications with operating temperatures between 200 ºC and 650 ºC; however mineral wool can be used in the range 90 ºC to 425 ºC and has slightly better thermal resistance than calcium silicate at lower temperature ranges, and is typically less costly. However calcium silicate has better compressive strength and therefore is generally more durable.

Physical Properties

Installed Cost Ref Density Max Temp Thermal Conductivity
Low to medium 190 kg per cubic meter 647ºC 0.055 W/m*ºK
UV Resistance Flame Spread Smoke Developed  Compressive Strength
High 0 0 860 kPA (or 125 PSI)